Amalgam Fillings: Do Dental Patients Have a Right to Informed Consent?

By Michael A. Royal


An individual may seek the services of a dentist for any number of reasons. After examination, the dentist may determine that the patient has a cavity and inform the patient that the cavity must be filled.

Dentists usually do not consult patients to determine what materials to use. Most feel that dialogue with the patient on this issue is unnecessary. However, some materials may be hazardous under certain conditions. There is considerable controversy regarding the use of mercury amalgam or “silver.”

However, the American Dental Association (ADA) supports the use of such fillings and assures “the American people that dental amalgam is safe.”1 The ADA claims that since mercury amalgam has been used for over 150 years, its safety should not be disputed.2While its position remains largely unsupported by scientific evidence, the ADA challenges those opposed to the use of amalgam fillings (anti-amalgamists) to produce scientific evidence that its use is harmful to humans.3 This challenge has been accepted. The anti-amalgamists have countered by challenging the ADA to demonstrate that safe levels of mercury in human tissues exist before endorsing its use.4 The ADA has yet to respond. Both sides do, however, agree that ” [mercury] is one of the most poisonous elements known to man, and mercury amalgam may cause ill effects in those people who are mercury sensitive.”5

The mercury used in fillings is hazardous before and during their preparation.6 Also, scrap materials pose an environmental hazard when discarded.7 Research over the past decade demonstrates that their use poses a potential health hazard to a significant number of the estimated 200 million Americans with amalgam fillings.8 Amalgam continues to be the primary filling material in the U.S., largely due to the ADA’s endorsement.9

This article will first examine the history and general issues involved in the use of amalgam fillings. Second, it will review available research to demonstrate the potential health hazards. Third, it will briefly investigate environmental issues and suggest that potential risks extend beyond those posed for patients. Ultimately, the article will address whether, whatever uncertainty may be present, patients do not have a right to be informed of potential risks and of available alternatives.

History of Amalgam Fillings

Opponents of amalgam have challenged its use in dentistry since its introduction over 150 years ago.10 The first reported use in dental restorations was in 1818.11 Since then, concerns over the toxic effects of mercury have persisted.12 The American Society of Dental Surgeons, formed in 1840,13 so abhorred the use of amalgam that it required its members to sign pledges that they would not use it.14 In 1848, The Society of Dentists of the City and State of New York suspended eleven of its members for “malpractice,” because they used amalgam.15 Internal strife over the use of mercury in dentistry led to the formation of the ADA, whose leaders did not oppose its use.16

In the late 1920’s, anti-amalgamists challenged the use of amalgam again, as evidence surrounding the toxic effect of certain mercury compounds “appeared indisputable.”17 Despite this, the use and popularity of amalgam in dentistry continued to grow rapidly.18Questions about its safety arose again about fifteen years ago and continue unabated.19 Nevertheless, mainstream dentistry believes it is “most unlikely” that the current “anti-amalgam crusade” will succeed in eliminating its use.20

Amalgam fillings typically comprise 50% pure elemental mercury, 35% silver, 13% tin, 2% copper, and a trace of zinc.21 The metal powders react with liquid mercury to produce an amalgam (or alloy)22 that provides a flexible material that can be easily packed and shaped.23 Amalgam fillings are often called silver fillings because of appearance and composition.24

The ADA prefers the use of amalgam because fillings are inexpensive and durable, while gold and other composite materials are more expensive and more difficult to fit.25 Because of its flexibility, the use of amalgam arguably requires less skill. Thus, dentists can usually fill a cavity in less time.26 Some, however, believe that alternatives that have been available for several years, may be even stronger and more durable.27 One author proclaimed over fifteen years ago that since “satisfactory alternative tooth-filling materials are available, … the use of amalgam fillings should be discouraged.”28 However, the ADA maintains that there are no acceptable substitutes,29 although it admits, “the use of composite resins as a posterior restorative material may eventually replace amalgam restorations.”30 In fact, the ADA recognizes that once an “acceptable” replacement for amalgam is found, that “even the possible hazard to dental office personnel of high levels of mercury vapor from mercury spills could be eliminated.”31

The ADA adamantly defends mercury usage in tooth restorations whenever others suggest that it poses a potential health threat on the basis that it has been used “safely” over the past 150 years.32 Other reasons behind its support of amalgam may include: 1) ease of use; 2) low cost; 3) additional training and equipment required to use alternative materials;33 and 4) potential liability associated with acknowledging the dangers of amalgam previously used. Unfortunately, the cost of a vast array of chronic, degenerative, mental and physical diseases related to mercury exposure in patients, dentists, dental personnel and society appears to be immeasurable.

Mercury Toxicity

Mercury has been known to be a poison for thousands of years,34 whether “ingested, inhaled, or absorbed through the skin.”35 In the 1800’s, British workers who used mercury in the hat making process developed symptoms of mental deterioration on an industry-wide basis.36 The expression, “mad as a hatter,” originated from that.37 Also, citizens of Minamata, Japan, endured ten years of misery, crippling deformities and agonizing deaths before industries ceased polluting the local harbor with mercury.38 The mercury was transferred to Minamata citizens when they consumed fish from the polluted harbor. This resulted in more than 10,000 cases of “Minamata disease,” which had a 10% mortality rate.39 Today, according to those involved in research, human exposure to mercury is primarily through dental amalgam.40

Mercury has been found to accumulate in vital organs and tissues, such as the liver, brain, and heart muscle.42 Major symptoms of mercury toxicity include emotional instability, tremors, gingivitis, and kidney failure.43 Some also believe mercury may be linked to multiple sclerosis44 and epileptic seizures.45 Further, its effect on the body’s immune system is potentially devastating,46 possibly contributing to diseases such as leukemia and hematopoietic dycrasias.47

No direct connection to any specific diseases has yet been made, primarily “because no one has really looked.”48 However, as research continues, evidence is accumulating. Dental fillings may yet prove to have effects many times greater than those found at Minamata.49

Patient Exposure to Mercury from Amalgam Restorations

Dentists maintain that mercury in “amalgam becomes inert once the fillings have been allowed to set for several days, and that long-term danger to the patient from [mercury] vapor is therefore remote.” 50 The New England Journal of Medicine recently reported, “Many important medical questions concerning mercury toxicity remain to be answered.”51 The ADA, by contrast, continues to assert that it has enough information to guarantee its safety for use.52

Nevertheless, dentists admit that there is exposure to mercury vapor,53 and the ADA acknowledges that an allergic reaction poses “small but possible risk to the patient.”54 However, approximately eleven million Americans are mercury sensitive.55 Further, the ADA agrees that the removal of amalgam fillings “can release relatively large amounts of mercury into the mouth and that may be harmful.”56

While de-emphasizing possible risks to patients, the ADA has taken affirmative steps to inform dentists and their personnel of the potential hazards57 of mercury and has established strict guidelines for storing and handling amalgam.58 One author suggests that dentists have both a “moral” and a “legal” duty to protect dental personnel.59 Because the primary danger in dental offices is “the atmospheric mercury vapor,”60 the ADA presents an interesting paradox in its position on amalgam. The organization considers the mercury vapors which threaten dental personnel are “insignificant.”61

Recent studies have found that substantial amounts of mercury vapor are released from dental amalgam after chewing gum for just ten minutes.62 Studies have also shown that mercury vapor can be released by “brushing the teeth with commercial toothpaste,”63“chewing food, drinking hot beverages, and smoking cigarettes.”64 Therefore, mercury vapor is continually present.65

Mercury Toxicity from Amalgams

Although amalgam subjects dental patients to dangerous mercury vapor,66 when asked if mercury is poisonous, the ADA recommends that dentists answer patients in the following manner: “Not when used as amalgam…. [W]hen mercury is combined with other metals… it reacts with them to form a biologically inactive substance.”67 The ADA instructs its dentists not to inform patients that amalgam continuously releases mercury _ even if patients inquire.68 No governmental agency has established safe standards for mercury intake from dental amalgams. Some experts believe “there is no safe level of mercury exposure.”69

The ADA investigated the possible effects of amalgam fillings in 1984 and assured the nation that, “although there is no evidence of a health threat, we will pursue the question of safety until the matter is resolved to the satisfaction of the American people.”70 The 1984 Workshop on The Safety and Biocompatibility of Metals in Dentistry concluded that mercury is released from amalgam fillings.71 Nevertheless, the ADA maintained that 
no health problems could result from such a small amount of exposure.72 When subsequent studies surfaced linking amalgam fillings to several incurable diseases, the ADA denied all claims that amalgam could possibly be responsible73–while reassured those concerned that it would “continue” to do everything in its power to resolve any questions as to its safety.74

In response to claims concerning amalgam hazards in 1987, the ADA boldly responded that such claims are unfounded,75 “unsubstantiated, undocumented, and unproven.”76 However, numerous studies performed since 1981, “demonstrate a positive correlation between dental amalgams and mercury levels in the human brain.”77

Other countries have taken action to limit or prohibit the use of amalgam fillings. Two years ago, the Swedish government “recommended that dentists stop using amalgam to fill the teeth of pregnant women.”78 Since then, Swedish authorities determined to ban the use of all mercury, including its use in amalgam fillings, by 1991, have urged that its use in pregnant women cease immediately.79 Viking Falk, division chief of the Swedish Social Welfare and Health Administration, said, “We now realize that we have made a mistake. This has caused people to suffer unnecessarily.”80 The ADA “quickly regarded [this report] as “bogus”81 However, the Swedish ban was subjected to public hearings and subsequently upheld.82 In fact, in November, 1990, the Swedish government passed a law providing its citizens the opportunity to have their amalgam fillings removed under the national dental plan.83 Also, legislation has been introduced in Germany to ban the use of amalgam.84 In Japan, dentists have likewise sought to use alternatives to amalgam.85

Current research demonstrating strong evidence of chronic mercury toxicity in patients with amalgam fillings has done little to persuade the ADA to reevaluate its position. Some dentists have suggested that their patients consider changing their amalgam fillings and replace them with nontoxic materials, based on current research. The ADA has labeled the actions of these dentists “unethical,” stating that dentists engaging in this practice raise “a question of fraud or quackery in all but an exceedingly limited spectrum of cases.”86However, current research has prompted groups, such as the Environmental Dental Association (EDA), to call for a ban on any use of mercury in dental materials.87 The EDA contends that using amalgam without informing the patient of associated risks and alternatives is “unethical.”88 A summary of recent scientific findings, which follows, suggests that health threats from amalgam exist in laboratory animals and probably in humans.

Current Research

Researchers from the departments of medicine, pathology and physiology from the University of Calgary, Alberta, Canada, performed revealing experiments during 1989 and 1990 regarding the safety of amalgam fillings. Two studies examined the effects of amalgam fillings on sheep, while a third studied its effects on monkeys. The 1989 study placed amalgam fillings into the mouth of a four-years-old ewe for 29 days.89 At the end, mercury was absorbed in the lungs90 (due to “continual breathing of the `intraoral air’ having mercury vapor”), the stomach91 (through “the mixing of intraoral Hg vapor, amalgam microparticles, and dissolved mercuric ions with saliva and food before swallowing”), the jaw92 (“some tissues in the jaw… and tooth root and surrounding bone”), “the brain and several endocrine glands.”93 The kidneys had high concentrations of mercury,94 which disproves earlier theories that mercury is excreted.95 The study concluded that, because about 8% of inhaled elemental mercury vapor is absorbed into the blood in humans, it immediately “becomes available for tissue retention.”96 Since the study found problems resulting from mercury exposure so quickly, amalgam fillings “remain[ing] in human teeth for eight to ten years… would allow an extended opportunity for body tissues to be continuously exposed to Hg [mercury].”97 The study concluded: “dental amalgams can be a major source of chronic Hg [mercury] exposure.”98

Another study, at the University of Calgary in 1990, investigated the effect of amalgam fillings on a fetus.99 Five pregnant ewes had amalgam placed in their teeth at 112 days gestation. This study demonstrated that mercury from amalgam fillings appear in maternal and fetal blood and the amniotic fluid within two days after placement of the dental restorations.100 The study concluded that amalgam also accumulates in maternal and fetal tissues.101 These results prompted the researchers to conclude: “Dental amalgam usage as a tooth restorative material in pregnant women and children should be reconsidered.”102 Mercury exposure is of particular concern in the developing fetus and in children due to their low body weight.103

A study performed ten years ago concluded that pregnant women should avoid exposure to mercury.104 Previous studies have also demonstrated that mercury exposure from amalgam can deteriorate the immune system.105 Although the Calgary studies did not show whether kidney functions returned after removal of the amalgam, Fritz L. Lorscheider, who was involved in both of the Calgary studies, concluded: “We know that mercury is highly toxic and that it concentrates in certain parts of the human body. From the sheep, we know it can alter kidney function in animals. That should be enough to get it banned...106

The University of Calgary studies were the first to demonstrate that changes in body functions occur following the implantation of amalgam.107 Shortly after publication, the findings were reported on the front page of the Chicago Tribune on August 15, 1990.108 The article quoted a Food and Drug Administration (FDA) representative as saying, “In light of emerging scientific data, the FDA needs to reexamine the use of amalgam. It may be necessary to reclassify amalgam and take various regulatory actions.”109 The FDA allowed the use of amalgam to continue in 1976 because the substance was already widely in use.110 Some believe the FDA’s decision to do so was largely because of the ADA’s influence within the FDA.111 However, after the animal tests at Calgary, the FDA would probably not allow amalgam to be used if it were a new product.112 Some Chicago dentists took exception to the Chicago Tribune’s decision to give the story so much prominence.113 The ADA has been accused by anti-amalgam dentists of actively seeking to avoid problems of liability which might arise through any admissions.114

A more recent study completed by the University of Calgary found that monkey kidneys, like sheep kidneys, concentrated large amounts of mercury when given amalgam fillings.115 Another study of two adult monkeys at the University of Georgia, in cooperation with the University of Calgary, concluded that bacteria normally present in the digestive tracts of monkeys were disrupted.116 The normal bacteria were replaced by a strain of mercury-resistant bacteria that recycle the metal in the body instead of allowing the monkey to excrete it.117 Preliminary research in human subjects indicates that people with silver fillings also develop bacteria that can use mercury.118 One researcher from the University of Georgia study stated, “This may… explain why not all mercury entering the body is excreted and high levels are found in certain organs. … It proves that mercury is `bio-available’– something that dentists have been denying for years.”119 However, the ADA dismissed the above “animal studies as irrelevant to humans,”120 although a monkey’s “dentition, diet, feeding regimen, and chewing pattern closely resemble those of humans.”121

The battle over use of amalgam appears to have become one of “medical science vs. dental opinion.”122 However, once the studies are duplicated and receive greater acceptance in the scientific world, David Eggleston of the University of Southern California School of Dentistry admits, “positions could change.”123

Amalgam and the Environment

Dental amalgam is classified as a hazardous material in the work place by OSHA, and excess dental amalgam must be disposed of according to OSHA’s Material Safety Data Sheet.124 However, the health threat of amalgam scraps may potentially reach far beyond the work place in the dental office. Although most of the industrial uses of mercury have been reduced, dental offices serve as a major source of mercury contamination in our environment. This occurs when dental personnel improperly dispose of scrap dental amalgam. For example, it can pollute ground and drinking water,125 or vapors released through incineration can pollute the air.126

Pima County, Arizona Dentists Suspended

Recently, the Pima County (Arizona) Wastewater Management Department, in cooperation with the Environmental Protection Agency (EPA), determined that local dentists were illegally dumping mercury into treated sewer water.127 Tucson experts discovered excess mercury in the Santa Cruz River, downstream from the county’s two sewer treatment plants.128 Officials traced the source to local dental offices, which were temporarily closed as a result.129 As of October 1989, 71 of the reported 73 mercury violations in Pima County (Tucson), since 1985, were directly traced to dental offices.130

The reason behind the strict Arizona environmental law lies in the delicate ecological system of the Santa Cruz River.131 However, local dentists maintained that the mercury must have come from other sources, and that amalgam poses no environmental threat. Richard Simoneaux, a Tucson dentist and Southern Arizona Dental Society President remarked, “There is mercury in the amalgam, but it’s OK to put amalgam in your mouth and it’s OK to put it in a landfill…. [W]e don’t want to pollute the environment and we don’t think what we are doing is wrong_we’re dumping amalgam, not free mercury.”132 The EPA does not agree.

EPA Takes Action in Connecticut

In 1988, a group of 58 New England dentists, the owners of a chemical company, an “amalgam broker,” and two dental supply companies incurred liability under Sec. 107 of the Comprehensive Environmental Response Compensation and Liability Act (CERCLA)133for improperly disposing of amalgam at two different waste sites.134 An EPA settlement resulted in payment of $69,812 –about 10% of the cleanup cost of $710,000.135

The U.S. filed suit,136 after which the other defendants eventually settled.137 The U.S. stated earlier in the pleadings that amalgam is an environmental hazard. In its complaint, the government averred that since “mercury, silver, copper and zinc are listed as hazardous substances under CERCLA… [and] these elements make up dental amalgams, [then] amalgam is itself a hazardous substance.”138

Before the consent decree, the ADA filed to appear, introduce evidence and make oral argument as amicus curiae on November 7, 1988. 139 The ADA hoped to have some influence on “whether dental amalgam is a regulated material under the provisions of CERCLA, and whether dental amalgam can be classified as a `hazardous substance’ pursuant to CERCLA.”140 After the settlement, the ADA confidently declared that the government’s position and the subsequent outcome had no affect on “[w]hether amalgam is safe for use in the mouth.”141 One of the dental supply defendants circulated a letter  following the settlement, interpreting the result as an official declaration by the government that amalgam was a hazardous substance.142 In an effort to squelch this misunderstanding, the ADA responded that, although the EPA considers amalgam to be hazardous, “[t]here has not been a decision by any court that finds dental amalgam to be a hazardous substance.”143 The ADA’s interpretation of the law appears to be in direct conflict with the government’s in the pleadings and consent decree.144 As for the circulated letter, the ADA fears it “has tripped an alarm that may be difficult to silence.”145

The ADA appears to be in a precarious position. While its stated purpose, as set forth in Bourdeaudhui,146 is “to advance the health of the public and to promote the art and science of dentistry…,”147 it incorrectly represents that dental amalgam has been “proven to be safe and effective….”148 Scientific research over the past several years is at odds with the ADA’s latter representation. The ADA’s refusal to seriously consider scientific findings regarding the hazards of amalgam fillings appears to be in conflict with its purpose as an organization.149 If amalgam fillings are hazardous to the public when dumped or otherwise disposed of, then they potentially threaten the community at large.150 In order to remain a credible organization, the ADA should welcome scientific research involving amalgam and other dental materials, and be willing to change its position when the health and welfare of dental patients and the public are compromised by dental procedures or dentists.151

Do Patients Have the Right to Know?

It would be prudent for the ADA, at this juncture, to reconsider its position. It should consider that many dental patients, once properly informed, might prefer some other substance as a filling material. For example, a physician has a duty to disclose to the patient the contents of a prescription and any potential side effects.152 Affirmative efforts are now being directed toward requiring dentists using amalgam to obtain informed consent from their patients. However, the ADA opposes any legislation designed to accomplish this.153

Traditionally, the law of informed consent “insists that an individual’s wishes be honored under all but a very few circumstances.”154 Justice Cardozo recognized that “Every human being of adult years and sound mind has a right to determine what shall be done with his own body….”155 Doctors were held to have a duty to inform patients in Salgo v. Leland Stanford, Jr., Univ. Bd. of Trustees,156 where the California Court of Appeals found that a physician has a duty to disclose “any facts which are necessary to form the basis of an intelligent consent by the patient to the proposed treatment.”157 Providing sufficient information to allow patients the opportunity for making informed decisions is one of the specific duties placed upon doctors as part of their responsibilities in providing professional care of their patients.158 This duty arises primarily from the doctor-patient relationship, because this “one-to-one relationship” facilitates “personal consultation and discussion.”159

Neither the ADA nor any American dentists are currently under a specific duty to inform patients of potential hazards of amalgam fillings, or to offer patients an option of available alternative materials. No affirmative duty will exist without state or federal legislation or without a resolution from a judicial proceeding. Generally, a duty usually exists where “reasonable persons would recognize it and agree that it exists.”160 Because the ADA “produces most of the dental health education material in the United States…,”161 and steadfastly refuses to acknowledge the dangers of mercury exposure through amalgam fillings, related health hazards may continue to go largely unnoticed.162 The ADA’s present posture in defense of mercury in dentistry has disastrous implications. While insisting that this “very serviceable, low-cost restorative material should [be made] available to the public,” the ADA fails to acknowledge the importance of providing information to patients about the dangers of amalgam. The public should be informed by dentists of the possible dangers associated with amalgam, and provided the opportunity to select other available materials. If the cost of dental treatment is of prime importance, then the patient should have the benefit of weighing the low-cost benefits of amalgam against potential hazards associated with chronic mercury exposure. Once a patient knows the risks, perhaps a more expensive substance would become more desirable.

Often, litigation of this kind arises from a doctor’s failure to disclose material information to the patient.163 Courts presume that people do not desire to be harmed or incur the risk of being harmed.164 This presumption requires the doctor to demonstrate that the patient was informed of and consented to the risk.165 In order to succeed in a suit for informed consent based on negligence, the plaintiff must establish that a duty to disclose exists.166 Once a duty is established, a clear nexus between causation and the resulting harm must be shown.167 While research may provide enough evidence for a victim of mercury toxicity from amalgam fillings to demonstrate potential hazards, the causation element poses the biggest obstacle for the plaintiff. Absent a statute, expert testimony is necessary in order to establish a duty and then to show that the nondisclosure resulted in the harm under negligence doctrine.168

Most states use an objective standard of causation in such cases.169 However, jurisdictions differ as to who may establish the standard. The majority rule compels a doctor “to disclose facts which a reasonable medical practitioner in a similar community and of the same school of medical thought would have disclosed to his patient regarding the proposed treatment.”170 This standard requires the plaintiff to demonstrate the necessity of disclosure through expert testimony.171

One minority approach views the nondisclosure from the patient’s point of view. In the decision making process, based on what the doctor knew or should have known about the patient’s position, courts using this approach weigh whether a reasonable person under similar circumstances would have been likely to attach significance to the information provided.172 This latter standard does not require expert testimony, but leaves “the court to look only at what the reasonable person deems to be material in making an informed decision.”173 A noted trend has been to follow the minority view, which adheres to the rule that “the duty to disclose should be measured by the patient’s need for information rather than by the standards of the medical profession.”174

Dentists who continue to use amalgam, despite scientific data raising questions as to its safety, may argue that the patient needs no informed consent because “the procedure is simple and the danger remote and commonly appreciated as remote.”175 However, the plaintiff may dispute this defense with expert testimony.

A suit brought on grounds of products liability would be difficult since the patient never sees and never handles the amalgam. Therefore, no labels with warnings to patients would be effective.176 However, the FDA may soon reclassify amalgam “so that sometime in the future manufacturers of these particular products would have to provide safety and effectiveness data.”177 Still, the dental patient is wholly reliant on the dentist to provide information and facts relating to inherent risks and other alternatives.178

Class Action Suit Against ADA179

How will the courts determine whether a dentist, or an organization, has acted reasonably? Is the dentist who strictly adheres to the doctrine of the ADA reasonable? What about the dentist who concludes from available research that amalgams present a significant risk for patients? For him, being reasonable may result in harassment by the ADA and loss of licensure to practice, as determined by his peers on the state licensing board. A federal court will likely decide this issue in the near future. On September 20, 1990, a class action suit (hereinafter Kennedy) was filed in federal court.180 Forty anti-amalgam dentists have charged the ADA with fraud for continuing to claim that amalgam fillings are safe.181 The Kennedy action also alleges that the ADA has harassed the plaintiff dentists and attacked their professional reputations as a direct result of the plaintiffs’ efforts to expose hazards of amalgam fillings.182 The plaintiffs further charge the ADA with continuing to deceive the American public with assurances about amalgam fillings, despite vast scientific evidence, “because they feared the embarrassment and liability of being proven wrong, and because they feared that admission of their misrepresentations would result in a public relations disaster for themselves.”183 The plaintiffs in Kennedy are seeking compensatory as well as punitive damages, an injunction enjoining the ADA from discriminating or otherwise “intimidating” the plaintiffs, together with an order requiring the ADA “to correct their wrongdoings.”184

One attorney writes: “[t]he most expeditious way to bring about change is to resort to the courts for punitive damages in certain cases that involve suppression or destruction of evidence, or fraud by manufacturers on the public or in the medical profession.”185However, several groups are taking the legislative route to change, proposing laws requiring informed consent.

Legislative Efforts to a Solution

The EDA has called for a ban on the use of mercury in dental fillings and is actively promoting informed consent legislation in several states.186 Colorado may emerge as the leader in strengthening rights of dental patients. This year, new legislation has been introduced imposing a specific duty on dentists to provide informed consent to their patients before placing dental amalgams in their teeth. The proposed legislation would impose strict liability on dentists who fail to obtain informed consent from dental patients.187 In addition, the proposed legislation has sought to relieve dentists of any liability to the state dental board for recommending the removal of amalgam fillings in the interest of the patients’ health.188 Arguably, the existence of a health hazard should be brought to the attention of patients through informed consent. Patients need to know about the availability of safer alternative materials, despite higher costs and alleged inferior quality.189 Inasmuch as patients must accept the consequences of the fillings placed in their teeth, the proposed legislation in Colorado would leave the decision to the patient, not the dentist.

Commentary supporting the proposed amendments suggests that dentists should be under the same obligations as other Colorado health providers who perform treatment or procedures which expose the patient to a significant risk.190 Proponents of the Colorado legislation reason that “[b]ecause the potential harm is great, and minimal effort is needed to inform patients of this potential harm, it would be reasonable for dentists to provide this information to their patients before using amalgam.”191 In addition, advocates admonish state leaders that, at a minimum, this legislation will protect “those persons who are more susceptible to or affected by toxic poisons.”192 Specifically, the proposed statute would require dentists to inform patients that mercury is in amalgam fillings, the mercury can have toxic effects, alternative materials are available and the patient has the right to choose an alternative material.193 Previous Colorado legislation in this area has failed because representatives of the Colorado Dental Association, like the ADA, have said they do not believe silver fillings are a health threat.194 The ADA has labeled such legislation as “A wolf in legislative clothing.”195

In Alaska, State Senate majority leader Pat Rodey reported that enough evidence exists to establish “reasonable doubt” as to the safe use of dental amalgam.196 He therefore introduced a senate resolution, similar to the Colorado proposal, which would require informed consent from dental patients before the use of amalgam fillings in patients.197 The Alaska Department of Health and Social Services advised in a “Concept Paper” in January, 1989, “persons who have had a large number of amalgam fillings, who have experienced symptoms commensurate with chronic low level mercury exposure and who have tried traditional treatments may wish to consider replacement therapy.”198 The proposed Alaska legislation did not pass as introduced initially,199 but is being reintroduced again this year.

Last year, the Illinois House of Representatives adopted a House Resolution which requested that 200 the Illinois Department of Public Health review the studies that have examined the health risks of mercury in dental fillings and report to the General Assembly by March 1, 1990, its finding about such risks as well as its recommendations for providing a means by which dental patients may be informed of the findings and of the alternatives to mercury content in fillings when seeking dental treatment.

The resolution was referred to the committee on assignment. No study was performed, and the bill died in committee. However, it will likely reappear in future sessions. North Carolina is another state which has considered legislation structured to provide dental patients with information about amalgam fillings.201

The legislative process is often slow and “replete with economic and political considerations and often falls wide of the mark.”202 Over the past decade, the ADA has postured itself to fight and discredit scientific research, rather than seek a cooperative venture with fellow scientists to resolve the matter in good faith.203 It is difficult to understand why the ADA does not favor informed consent legislation, since “Empirical evidence suggests that even when undesirable medical outcomes occur, the greater the degree to which the patient participates and is informed, the less likely she is to file a malpractice claim.”204 By endorsing informed consent, however, the ADA would have to alter its position on amalgam fillings, and would give credence to advocates opposing the use of amalgam materials.205 The ADA’s position that amalgam is safe based on 150 years of use is weak at best.206 The ADA has not produced scientific data which demonstrates the safety of amalgam fillings. In so doing, it has arguably failed in its duty to protect the public, as well as its own membership, from personal harm due to amalgam usage.207

The ADA may fear the flood gates of litigation will burst when the American people have all the necessary information about the potential harmful effects of mercury in amalgam. Intense litigation often follows when the public discovers it has been unnecessarily exposed to toxic substances.208

Historically numerous common products were thought to be safe; for example[,] asbestos, lead, and DDT. In each case the scientific concerns were immediately discounted by the industry responsible for the production or use of the material and often the assertions of safety were initially supported by the responsible government agencies. After a period of time as the evidence became overwhelming and legal liability impossible to ignore, they were regulated or withdrawn from the market. Each of these products demonstrated pathology after a latency period of chronic low dose exposure[,] as does mercury.209

Perhaps the Kennedy210 case will provide swifter resolve to the amalgam issue and result in adequate information concerning the risks of amalgam fillings being disseminated to dental patients. Freedom of choice means patients must receive the information necessary to allow the best possible opportunity to make an informed decision as to what dental procedures or materials will be used.211 This should no longer be a decision reserved for the dentist’s sole discretion.


One author of a dental text advocates the use of amalgam fillings based on a risk/benefit analysis, because “the benefit from the treatment far outweighs any side effects from operative procedures and dental materials.”212 However, with so many alternative materials available, this risk/benefit approach makes little sense. Since the ADA’s declarations of the safety of amalgam fillings is based on tradition and remains unsubstantiated by research, dentists should reassess their legal and ethical positions. With respect to recent scientific findings about amalgam fillings, dentists can no longer expect credible support from the ADA, and should perform due diligence in obtaining knowledge and information on this subject.213 While the FDA anticipates regulatory changes based on recent research, one reporter writes: “Until then, add amalgam fillings to the list of risks Americans must decide whether or not to bear.”214 However, no rights to make such an informed decision are currently afforded to individuals in this country by law.

Legal implications for dentists using the amalgam fillings are mounting. Evidence of amalgam toxicity and the availability of safer alternative materials, arguably, substantially increases the liability of the ADA and pro-amalgam dentists. One attorney has predicted that mass tort litigation from amalgam poisonings will soon become a “major courtroom event.”215 The class action suit in Kennedy216 may only be the tip of the litigation iceberg. Depending on the outcome of this case, “the mass litigation which will follow may well exceed other mass toxic tort cases….”217 The evidence available suggests, “the mercury amalgam issue is an internal Love Canal waiting to be exposed.”218 If this is correct, then the ADA, its members and other pro-amalgam dentists may soon have an opportunity to defend their position in the courts. Ultimately, it may take federal legislation to save traditional dentistry from financial ruin.219


  1. H Queen, Chronic Mercury Toxicity, New Hope Against an Endemic Disease 24 (1988) (quoting Dr. Donald E. Bentley, ADA President, Bureau of Communications, 211 East Chicago Avenue; Chicago, Illinois 60611) (Special News Release II: ADA President Underscores Safety of Dental Fillings, 1983). See also, Council on Dental Materials, Instruments, and Equipment, Council on Dental Therapeutics, Safety of Dental Amalgam, 106 J.A.D.A. 519, 520 (1983) (“the use of mercury in dental amalgam restorations is safe for patients.”) [hereinafter Safety of Dental Amalgam].
  2. See infra note 139.
  3. See Friedman, Safety of Dental Amalgam, 260 J.A.M.A. 2295, 2296 (1988) (“There is no evidence that the presence of amalgam restorations poses any risk to the patient.”). See also, Special Report: When Your Patients Ask About Amalgam, 120 J.A.D.A. 398 (1990) [hereinafter Special Report].
  4. H. Queen, supra note 1, at 24. “Suspected chronic exposure to mercury from dental amalgam should no longer be questioned.” Id. at 22 (citing Vimy & Lorscheider, Serial Measurements of Intraoral Air Mercury: Estimation of Daily Dose from Dental Amalgam, 64 J. Dent Res 1072 (1985)). See also, H. Huggins & S. Huggins, It’s All In Your Head 9 (1985) (“In the hundred of articles we have accumulated on mercury in the body[,]… we have not been able to find even one that would support the claim that mercury is harmless to the patient.”); Hahn, Kloiber, Vimy, Takahashi & Lorscheider, Dental `Silver’ Tooth Fillings: A Source of Mercury Exposure Revealed By Whole-Body Image Scan and Tissue Analysis, 3 Federation AM, Societies for Experimental Biology J. 2641 (1989) [hereinafter Dental `Silver’ Tooth Fillings] (footnotes omitted) (“[C]lear experimental evidence regarding its safety has not been demonstrated.”); International Academy of Oral Medicine and Toxicology, a Scientific Response to the International Academy of Oral Medicine and Toxicology, A Scientific Response to the American Dental Association’s Special Report and Statement of Confidence in Dental Amalgam 1 (1990) (“In the interest of public safety, we reaffirm our 1985 position that the use of… mercury/silver fillings should be discontinued until such time as primary pathological evidence of amalgam safety is produced.”); CBS News,”Is There Poison In Your Mouth?”, 14 60 Minutes 2, 3 (CBS television broadcast, Dec. 16, 1990) (transcript may be obtained from CBS News, 60 Minutes Transcript, 542 West 57th Street, New York, New York 10019; transcript on file at Princeton University General Library, University of Michigan General Library, and University of Iowa General Library) [hereinafter 60 Minutes] (Dr. Murray Vimy, researcher and dentist at the University of Calgary Medical School stated: “This issue is, chronic exposure, low dose, to a heavy metal…. [N]o one has ever really looked at that aspect of mercury exposure.”).
  5. H. Queen, supra note 1, at 24. See W. Shafer, M. Hine & B. Levy, A Textbook of Oral Pathology 578 (4th ed. 1983) (“A toxic reaction from absorption of mercury in dental amalgam has been reported on a number of occasions…. [T]his exposure may suffice to bring about allergies manifestations in patients sensitive to the mercury….”); D. Smith & D. Williams, 3 Biocompatibility of Dental Materials 29 (1982).
  6. R. Craig, W. O’Brien & J. Powers, Dental Materials: Properties and Manipulation 94 (4th ed. 1987) (“If mercury is improperly handled in the dental office, a health hazard may result from (1) systemic absorption of liquid mercury through the skin, (2) inhalation of mercury vapor, and (3) inhalation of airborne particles.”).
  7. See infra note 140.
  8. See infra note 55.
  9. Lee, Two Studies Suggest Risk From Silver Fillings, Chicago Tribune, Aug. 15, 1990, section 1, at 1, col. 2.
  10. H. Queen, supra note 1, at 15.
  11. D. Smith & D. Williams, supra note 5, at 20. See Dental Fillings Cited as Environmental and Health Hazard, PR Newswire, Raleigh, N.C., Apr. 5, 1990 (The use of amalgam fillings won popularity as a substitute for gold and toxic lead fillings); J. TAYLOR, The Complete Guide to Mercury Toxicity From Dental Fillings 189 (1988) (“Although the detrimental effects of mercury were well known in the 1800’s, there was no inexpensive substitute for gold fillings except for the silver mercury fillings.”).
  12. D. Smith & D. Williams, supra note 5.
  13. J. Taylor, supra note 11, at 189.
  14. Id.
  15. Id. at 188 (citing M. Ring, Dentistry: an Illustrated History (1985)).
  16. Id. at 188.
  17. I. Mjör, Dental Materials: Biological Properties and Clinical EVALUATIONS 22 (Oslo, Norway, 1985).
  18. Id.
  19. Id.
  20. Id. See also, R. Craig, W. O’Brien, J. Powers, supra note 6, at 94 (“Until more esthetic restoratives that can function in stress-bearing areas are developed, amalgam will continue to be used.”).
  21. Dental `Silver’ Tooth Fillings, supra note 4, at 2641.
  22. R. Craig, W. O’Brien, J. Powers, supra note 6, at 94. “The hardening of the amalgam is the result of two phenomenon — solution and crystallization. When mercury initially comes into contact with the alloy, the particles are moistened by the mercury and they begin to absorb it…. The final result… is an amalgam with… superior properties.” Id. at 97.
  23. Id. at 94.
  24. Id. (“Mercury is a dense liquid metal that is highly toxic. Mercury of high purity possess a shiny surface.”). See also, D. Smith & D. Williams, supra note 5, at 21 (“The purity of dental mercury in the ADA specification is defined by the surface appearance, the residue after pouring, and the nonvolatile residues. Mercury that has a clean surface with mirror-like appearance and pours cleanly can be used satisfactorily for dental purposes.”).
  25. Special Report, supra note 3. See also, “County Says Dentists Are Dumping Excess Mercury”, Arizona Daily Star, Oct. 16, 1989, at B1, col. 1. “If we can’t use the mercury amalgam, we’ll have to use gold _and a $30 filling will cost $200 or more.” Id. (quoting Richard Simoneaux, a Tucson dentist and Southern Arizona Dental Society President).
  26. See generally id.
  27. See Choulos & Weiner, It is More Probable Than Not That We will Soon Become Mad As Hatters, or The Legal and Health Effects of the Use of Dental Amalgams, 4 San Francisco Barrister 10, 13 (Jun. 1985).Advantages of Using Enamel and Dentin Bonding composites vs. Amalgams: They contain no mercury…. They are more thermally insulating and protect the pulp better from temperature changes. They attain full strength very quickly and thus reduce failure from lack of strength and permit finishing and polishing to be done during one placement and appointment. Preparations may be more conservative with less tooth structure lost; little mechanical retention necessary by bonding to tooth structure; and tooth strength increases rather than decreases. No corrosion products are created. Composites have very good esthetics. There is extremely limited marginal leakage.Id. (quoting M. Ziff, D.D.S., J.E. Hardy, M.D., presentation to Florida Academy of General Dentistry (July 23, 1983)) (emphasis added). See also, Peterson, FDA May Take Closer Look at Silver Fillings’ Safety, USA Today, Oct. 24, 1990, at D4, col. 1 (David Eggleston of the University of Southern California School of Dentistry stated that, “Dental amalgams will [soon] be phased out because of better materials that will be available at the same cost.”).
  28. L. Dickey, Clinical Ecology 295 (1976).
  29. One ADA expert writes: “The profession has been using amalgam for more than 150 years, and some of these newer materials have been around for only a decade or less, so we don’t have the longstanding of safety with them that we have with amalgam.” Special Report, supra note 3, at 396.
  30. National Instititute of Dental Research, Workshop: Biocompatibility of Metals in Dentistry, 109 J.A.D.A. 469, 471 (1984) [hereinafter Biocompatibility].
  31. Safety of Dental Amalgam, supra note 1, at 520.
  32. Supra note 29.
  33. “If you took amalgam off the market tomorrow, a good 40 percent of the American dentists who belong to the American Dental Association would have to be retrained, because in their practices, the prime [material] that they use is dental amalgam.” 60 Minutes, supra note 4, at 10 (quoting Dr. Murray Vimy, researcher & dentist from University of Calgary Medical School).
  34. D. Smith & D. Williams, supra note 5, at 20 (Mercury toxicity was observed in humans as early as 380 B.C.).
  35. H. Queen, supra note 1, at 15 (emphasis in original).
  36. L. Dickey, supra note 28, at 294.
  37. Id. at 294 (The Mad Hatter, in Alice in Wonderland “had the characteristic slurred speech of the worker in the industry.”). See also, H. Queen, supra note 1, at 16.
  38. Ingalls, Endemic Clustering of Multiple Sclerosis in Time and Place, 1934-1984, 7 Am. J. Forensic Med. & Pathology 3, 6 (1986).
  39. Id.
  40. See Vimy, Luft & Lorscheider, Estimation of Mercury Body Burden from Dental Amalgam Computer Simulation of a Metabolic Compartment Model, 65 J. Dent. Res 1415 (1986); Drilling for Danger?, Newsweek, Oct. 15, 1990, at 80 (“fillings can be the largest single source of exposure to inorganic mercury”). See also, Mercury_ An Element of Mystery, 323 New Eng. J. Med. 1137, 1139 (editorial by Thomas W. Clarkson, Ph.D., M.D.) (“Amalgam tooth fillings are… possibly the chief source of exposure of a large segment of the U.S. population.”).
  41. D. Smith & D. Williams, supra note 5, at 33. See also, Eggleston & Nylander, Correlation of Dental Amalgam with Mercury in Brain Tissue, 58 J. Prosthetic Dent 704 (1987) (“Organic mercury compounds and elemental mercury vapor can cause central nervous system damage, and long-term exposure to inorganic (metallic) mercury vapor from dental amalgam may increase the brain tissue concentration of the neurotoxic metal.”); Mercury–An Element of Mystery, supra note 40, at 1138 (“Autopsy data indicate that brain mercury levels are approximately twice as high in people who have had fillings for many years as in those with no fillings….”).
  42. H. Queen, supra note 1, at 20.
  43. D. Smith & D. Williams, supra note 5, at 20. See also, Vimy, Takahashi & Lorscheider, Maternal-Fetal Distribution of Mercury (203Hg) Released From Dental Amalgams, 27 Am. J. of Physiology: Regulatory, Integrative & Comparative Physiology, 944 (1990) [hereinafter Maternal-Fetal Distribution] (footnote omitted) (“Both kidney and liver were shown to be major sites of Hg deposition when human subjects inhaled [mercury] vapor from a nonamalgam source, and kidney and brain are considered to be critical target organs for Hg vapor effects.”).
  44. See Ingalls, supra note 38, at 3. See also, Lee, supra note 9; 60 Minutes, supra note 4, at 4-5 (clinical evidence demonstrated some sufferers from multiple sclerosis were dramatically cured or relieved soon after removal of their amalgam fillings).
  45. H. Queen, supranote 1, at 253.
  46. Eggleston, Effect of Dental Amalgam and Nickel Alloys on T-lymphocytes: Preliminary Report, 51 J. Prosthetic Dent. 617, 619 (1984) (footnotes omitted) (“An abnormal T-lymphocyte percent of lymphocytes or a malfunction of T-lymphocytes can increase the risk of cancer, infectious diseases, and autoimmune diseases.”).
  47. Huggins, Proposed Role of Dental Amalgam Toxicity in Leukemia and Hematopoietic Dycrasias, 11 IntJ. Biosocial & Med. Res. 84 (1989). See also, Royal, When Traditional Oriental or Modern Medicine Fail: Could Dental Amalgams Be Contributing to Our Declining Health ?, 18 Am. J. Acupuncture 205, 210 (1990) (“Chronic mercury intoxication, like syphilis, can mimic many different diseases as it slowly destroys cells, tissues and organs….”).
  48. See Drilling for Danger?, supra note 40.
  49. “It is believed that dental amalgams constitute the major source of exposure to inorganic Hg in the general population.” Hahn, Kloiber, Leininger, Vimy & Lorscheider, infra note 115, at 3256 (footnote omitted).
  50. Dental `Silver’ Tooth Fillings, supra note 4, at 2641 (footnote omitted). See also, R. Craig, W. O’Brien & J. Powers, supra note 6, at 97. It should be clearly understood… that once amalgamation occurs, for all practical purposes, no free (unreacted) mercury is associated with the amalgam restoration. The mercury in an amalgam is alloyed with silver or tin and no longer has the toxic properties of unreacted mercury. If, however, amalgam is heated beyond approximately 80 C, liquid mercury can form on the surface of the amalgam, and its vapor can present a health hazard. Id. But see Biocompatibility, supra note 30, at 470 (“Additional studies in this area are required to more accurately assess the possible risk to patients.”); International Academy of Oral medicine and Toxicology, supra note 4, at 3 (citing Stock, Die Gefahrlichkeit des quecksiberdamphes, 39 Z. Agnew Chem. 461 (1926)) (“Published experimental evidence as early as 1926 has demonstrated that mercury is not locked in, but is released from fillings.”).
  51. Mercury — An Element of Mystery, supra note 40, at 1138.
  52. Supra note 1.
  53. One author writes: [T]here are ample experimental data which show that measurable amount of mercury vapor is released from both newly placed and aged amalgams…. [However,] the available evidence suggests that the health hazards of mercury to patients from amalgam restorations are negligible, with the exception of allergic reactions…. The potential danger to patients from mercury vapor inhalation in the dental office is considered remote because of the short duration of the office visit. D. Smith & D. Williams, supra note 5, at 28-29.
  54. R. Craig, W. O’Brien, J. Powers, supra note 6, at 95. See W. Shafer, M. Hine & B. Levy, supra note 5.A toxic reaction from absorption of mercury in dental amalgam has been reported on a number of occasions…. [A] thorough review of the literature and numerous studies on the absorption and excretion of mercury [indicates] that the amount of estimated exposure to mercury from dental amalgam is not sufficient to cause mercury poisoning in the conventional sense. Nevertheless this exposure may suffice to bring about allergies manifestations in patients sensitive to the mercury….Id. See also, I. MJÖR, supra note 17, at 24 (“allergy to mercury is a real, reported, and documented side effect. However, its frequency is low and the clinical symptoms are usually of insignificant nature.”).
  55. See Dental `Silver’ Tooth Fillings, supra note 4, at 2645 (footnote omitted) (“In North America 5.4% of the population display contact hypersensitivity to Hg [mercury].”).
  56. Richards, Maverick Dentists Question Safety of Typical Fillings, Wall St. J., Nov. 28, 1988, at B1, col. 5. See also, Biocompatibility, supra note 30, at 470 (“Studies have demonstrated that patients are exposed to mercury vapor when amalgams are placed as a restoration….”); Peterson, supra note 27 (quoting David Eggleston, researcher and dentist with the University of Southern California School of Dentistry) (“when amalgam is removed, `there is a temporary elevation of mercury in the blood…. The first trimester of pregnancy would be of particular concern.”); infra note 79 (regarding threats to pregnant women and mercury exposure).
  57. See ADA Advertisement, Protect Yourself and Your Staff… Against One of the Hazards of Your Profession With the ADA’s Mercury Testing Service (copy available from American Dental Association, Council on Dental Research, 211 East Chicago Ave., Chicago, Illinois, 60611 1985); Brodsky, Cohen, Whitcher, Brown, Jr. & Wu, Research Reports: Occupational Exposure to Mercury in Dentistry and Pregnancy Outcome, 111 J.A.D.A. 779, 780 (1985) (“For dental personnel, mercury is absorbed directly into the body through handling and by inhalation of mercury vapors.”).
  58. ADA RecommendationsMercury has a high vapor pressure and should be stored in a cool place. Baseboard heaters should be avoided since spills collect at the edges of rooms and the higher temperature at the baseboard will raise the mercury vapor level above the safe limit. Carpeting of operatories is not recommended to avoid absorption of any spilled mercury. A no-touch technic of handling mercury should be used. Water spray and high-volume evacuation should be used when removing old amalgam restorations or finishing new ones since heating releases some mercury vapor. A face mask should be used to avoid breathing amalgam dust.R. Craig, W. O’Brien & J. Powers, supra note 6, at 95. The ADA also recommends “a yearly mercury urinalysis of all dental office personnel.” D. Smith & D. Williams, supra note 5, at 23 (footnote omitted). However, “urinary mercury levels appear to have little or no diagnostic significance, and are useful only as a convenient means of assessing whether mercury exposure has occurred.” Id. at 26. See also, Biocompatibility, supra note 30, at 470 (“there appears to be little correlation between levels in urine, blood or hair, and toxic effects.”).WARNING: If mercury is improperly handled in the dental office, a health hazard may result from (1) systemic absorption of liquid mercury through the skin, (2) inhalation of mercury vapor, and (3) inhalation of airborne particles.”R. Craig, W. O’Brien & J. Powers, supra note 6, at 94. Recent surveys suggest that one out of ten dental offices in the U.S. may be in technical violation of the mercury exposure limit as recommended by the National Institute for Occupational Safety and Health (NIOSH) at 0.05 mg of mercury per cubic meter of air determined as a time-weighted average for an 8 hr. work day. D. Smith & D. Williams, supra note 5, at 23 (footnotes omitted).
  59. D. Smith & D. Williams, supra note 5, at 22.Occupational exposure of personnel to potentially hazardous levels of mercury vapor is a very real concern to the practicing dentist in the U.S. because of (1) moral responsibility to protect self and employees from any source that may constitute a serious threat to health and welfare, and (2) legal responsibility as an employer under the Occupational Safety and Health Act [OSHA] of 1970. … Currently, OSHA enforces a standard of 0.1 mg mercury per cubic meter of air in the work place.” Id. (emphasis added).
  60. Id. at 21. “Inhalation of mercury vapor in the atmosphere is the major exposure route in dental personnel….” Id. at 33.
  61. See Choulos & Weiner, supra note 27, at 11.With approximately 85 percent of the population in the United States carrying mercury and nickel amalgam fillings in their teeth, the American Dental Association… [is] very emphatic in precautioning dentists and technicians to protect themselves from known hazards of working with mercury compounds. Yet, this august body continues to recommend the use of mercury in the oral cavities of patients, including children.Id. (emphasis in original). See also, H. Huggins & S. Huggins, supra note 4, at 11 (“the dental association is telling us that the only safe place to store amalgam is in the mouth.”).
  62. Dental `Silver’ Tooth Fillings, supra note 4, at 2641 (footnote omitted) (mercury levels were six times higher than before gum chewing). See also, Maternal-Fetal Distribution, supra note 43, at R939 (“In humans, the continuous release of Hg vapor from dental amalgam tooth restorations is markedly increased for prolonged periods after chewing.”); Mercury — An Element of Mystery, supra note 40, at 1138 (“The vaporization of mercury is stimulated during chewing and for several minutes thereafter.’).
  63. Dental `Silver’ Tooth Fillings, supra note 21, at 2641 (footnote omitted).
  64. H. Queen, supra note 1, at 22-23. Another researcher concludes: “If the capacity of mercury vapors to inflict central nervous system injury is a proven fact, so, too, the capacity of lead fumes to deliver the metallic poison through inspired air is incontestable.” Ingalls, supra note 38, at 6 (1986) (citing Putman, Quicksilver and Slow Death, Natl. Geographic 507 (Oct. 1973)).
  65. See infra note 96.
  66. Choulos & Weiner, supra note 27, at 12 (“the growing concern is the possibility of immune suppression and other serious effects of mercury leaching from dental fillings.”).
  67. Special Report, supra note 3, at 395 (emphasis added). See also, International Academy of Oral medicine and Toxicology, supra note 4.It is a fallacy that mercury is neutralized when it is combined with other components of silver dental amalgam…. Mercury is diluted by the other components of amalgam in what may be considered a solid solution. Although the vapor pressure of mercury is reduced, mercury vapor is still released. Id. at 2 (quoting Dun, Harmful Vapors in the Office: A Report of the Findings of the 1985 ODA/RCDS Survey of Mercury Vapor in Dental Offices in Ontario, Ontario Dentist 37-38 (1988)).
  68. Special Report, supra note 3, at 395-96 (dentists are instructed to say, “no evidence exists that associates this minute amount of mercury vapor with any toxic effects.”). See also, Friedman, supra note 3. But see infra at 157 (research demonstrates that low doses of mercury have toxic effects).
  69. Lee, supra note 9 (citing mercury toxicity experts Thomas Clarkson of the University of Rochester Medical School and Lars Friberg of the Karolinska Institute in Stockholm, Sweden). See H. Queen, supra note 1, at 15 (“While acceptable limits are often quoted by the federal regulatory agencies and health agencies, mercury is a poison at any level….” (emphasis in original)). See also, Lee, supra note 9 (Michael Ziff, an Orlando dentist, stopped using amalgam about nine years ago and believes “[t]he ADA should stop the use of this material until it can prove amalgam is safe.”); International Academy of Oral medicine and Toxicology, supra note 4, at 3 (“Toxicology experts maintain that there is no threshold level of mercury exposure which can be considered totally harmless.”).
  70. H. Queen, supra note 1, at 253 (quoting Edgar W. Mitchell, Ph.D., secretary to the ADA’s Council on Dental Therapeutics, ADA News Release I: Experts to Review Safety of Metals in Dentistry (Dec. 1983)).
  71. H. Queen, supra note 1, at 253 (citing National Institute of Dental Research, Workshop: Biocompatibility of Metals in Dentistry, 109 J.A.D.A. 469 (1984)).
  72. H. Queen, supra note 1, at 253 (author’s note) (“To my knowledge, no further research (funded by either the ADA or NIDR) has been stated, or even planned, as a result of this workshop.”).
  73. Id. at 254 (quoting John Stanford, Ph.D., biochemist and secretary to the ADA Council on Dental Materials, Instruments and Equipment, ADA News Release I: Experts to Review Safety of Metals in Dentistry (Dec. 1983) (“There is no evidence relating dental amalgam to… diseases and afflictions [such as multiple sclerosis & epileptic seizures]. To our knowledge, no cause-effect relationship has ever been established.”).
  74. Id. (quoting Edgar W. Mitchell, Ph.D., secretary to the ADA’s Council Dental Therapeutics, ADA News Release I: Experts to Review Safety of Metals in Dentistry (Dec. 1983) (“We wish the public to be as certain as we are that dental amalgam is safe, and we will pursue this matter until that certainty is assured.”).
  75. Id. (quoting ADA president, Dr. Donald E. Bentley, ADA News Release II: ADA President Underscores Safety of Dental Fillings (Dec. 1983)). See also, Peterson, supra note 27 (ADA spokesman Chuck Green said, “There is no reason for the public to be concerned and no reason to seek removal of fillings.”).
  76. H. Queen, supra note 1, at 256 (quoting Richard Asa, ADA Manager of Media Services for the ADA, telephone interview in the spring of 1987).
  77. Eggleston & Nylander, supra note 42, at 704 (footnotes omitted). (“The ADA bases its position on studies performed in 1957 by Frykholm, indicating there is little or no risk to the patient. … However, Frykholm’s study did not address long-term accumulation of mercury on the brain tissue.”).
  78. Richards, supra note 56.
  79. 2 Dental & Health Facts 1 (Nov. 1989) (citing Atterstam, Socialstyrelsen Stops Amalgam Use, Svenska Dagbladet (May 20, 1987). See also, Eggleston & Nylander, supra note 42, at 706 (footnotes omitted).(“The temporary high levels of mercury in the blood immediately following the removal and placement of dental amalgam has been documented…. The removal and insertion of dental amalgam for gravid patients, or women of child-bearing age with the possibility of pregnancy, should be avoided whenever practical.”). See also, Peterson, supra note 27.
  80. Dental & Health Facts, supra note 79.
  81. S. Res. 12, 16th Leg., 1989 Alaska 1st. Sess. (“Concept Paper”).
  82. Id.
  83. 60 Minutes, supra note 4.
  84. Id. at 11 (re: Swedish laws) (“A total ban [in Germany] is expected within the year.”).
  85. Richards, supra note 56 (citing Nobumasa Imura, a professor at Kitasito University in Tokyo).
  86. The ADA has defined “quack” as “an ignorant or dishonest practitioner.” What Can Be Done About Dental Quackery?, 115 J.A.D.A. 679 (1987) (quoting Webster’s Medical Desk Dictionary.) However, it is unclear whether ADA members or other pro-amalgam dentists who continue to use amalgam fillings and refuse to acknowledge research pertaining to the safety of amalgam are sufficiently “ignorant” under the ADA’s accepted definition. But see International Academy of Oral medicine and Toxicology, supra note 4, at 9 (emphasis added) (“The ADA… is apparently suggesting that dentists deliberately violate their own code of ethics and withhold vital information from their patients and the public. Such action cannot help but intentionally violate the patients right to full informed consent.”); infra at 168.
  87. Dental Ethics and Mercury, Spotlight, Oct. 22, 1990, at 15, col. 1.
  88. Id. (EDA President Joyal Taylor, DDS: “Since no one knows just how little mercury it takes to cause permanent damage, as little exposure as possible [to] this powerful poison is the logical and moral course to take.”).
  89. Dental `Silver’ Tooth Fillings, supra note 4, at 2642.
  90. Id. at 2644.
  91. Id.
  92. Id.
  93. Id.
  94. Id. “The kidney and endocrine glands are known sites of autoimmune disorders, which brings into question the long-term implications of Hg [mercury] concentration in these tissues from dental amalgams….” Id. at 2645 (quoting Murray Vimy of University of Calgary). See Peterson, supra note 27 (“The average loss of kidney function [in the sheep] was 50%.”).
  95. Dental `Silver’ Tooth Fillings, supra note 21, at 2644. See also, infra notes 117 and 119.
  96. Id. (footnote omitted). See also, International Academy of Oral medicine and Toxicology, supra note 4, at 3. “[The] continual release of mercury will inevitably result in measurable exposure from the 17,000 breaths that a person inhales daily. Once this mercury is inhaled 74% to 100% of the mercury is absorbed from the lung into the blood stream and distributed throughout the body.” Id. (citing Goldwater, Ladd & Jacobs, Absorption and Excretion of Mercury in Man; VII Significance of Mercury in Blood, 9 Arch Env’t Health 735 (1964)).
  97. Dental `Silver’ Tooth Fillings, supra note 4, at 2645.
  98. Id. (footnote omitted) (“Our laboratory findings in this investigation are at variance with the anecdotal opinion of the dental profession, which claims that amalgam tooth fillings are safe. Experimental evidence in support of amalgam safety is at best tenuous.” (emphasis added)). See also, Hahn, Kloiber, Leininger, Vimy & Lorscheider, infra note 115, at 3256.
  99. Maternal-Fetal Distribution, supra note 43, at R939.
  100. Id. Highest concentrations of Hg from amalgam in the adult occurred in [the] kidney and liver, whereas in the fetus the highest amalgam Hg concentrations appeared in the liver and pituitary gland. The placenta progressively concentrated Hg as gestation advanced to term, and milk concentration of amalgam Hg postpartum provides a potential source of Hg exposure to the newborn. Id.
  101. Id. A study being prepared for publication, sponsored in part by Sweden’s Karolinska Institute, demonstrates that mercury penetrates the placentas of mothers. The mercury accumulates in infant brain tissue. Peterson, supra note 27. “There is a transportation of fairly high concentrations of mercury from the mother to the brain of the fetus…. And that is a warning.” Id. (quoting Dr. Magnus Nylander of Stockholm).
  102. Maternal-Fetal Distribution, supra note 43, at R939.
  103. International Academy of Oral medicine and Toxicology, supra note 4, at 3. See also, Dental Ethics and Mercury, supra note 87. But see Peterson, supra note 27 (Former president of the American Academy of Pediatric Dentistry disagrees with findings suggesting amalgam can be harmful, especially to children, and continues to use amalgam with the following endorsement: “I want nothing but the best for the children I see.”).
  104. World Health Organization: Recommended Health-Based Limits on Occupational Exposure to Heavy Metals. Report of a WHO Study Group, 467 WHO Tech. Rep. Ser. 1 (1980) (“Exposure of women of child-bearing age to mercury vapor should be as low as possible because elemental mercury readily passes the placental barrier.”). See also, Macdonald, Occupational Hazards in Dentistry, 12 J. Calif. Dent.. A. 17 (1984).
  105. Eggleston & Nylander, supra note 42.
  106. Lee, supra note 9. See also, Drilling for Danger?, supra note 40 (Researcher Murray Vimy of the University of Calgary said that “Mercury `seriously compromises’ organ systems in test animals… and `should be banned immediately'”); Peterson, supra note 27 (Murray Vimy of the University of Calgary research team challenged the pro-amalgam dentistry world “to investigate thoroughly the possible ramifications of [amalgam’s] use in humans.”).
  107. Peterson, supra note 27.
  108. Id.
  109. Id. (quoting Gregory Singleton, senior dental regulatory reviewer for the federal Food and Drug Administration). See also, Peterson, supra note 27 (the FDA may soon require manufacturers of amalgam to “provide safety and effectiveness data.”).The FDA’s Dental Products Panel recommended on March 15, 1991 that, while it was confident that amalgam fillings pose no threat to most people, more research must be done to “allay the fears of the public.” Panel Takes the Teeth out of Fears over Dental Fillings, Deseret News, March 16, 1991, at A3, col. 6. Dr. Manville G. Duncanson, Jr., chair of the panel, stated that although “animal studies show significant mercury absorption from dental fillings…, no studies have been done in humans and there is no evidence that amalgam fillings cause disease.” Id.
  110. Peterson, supra note 27. See also, Dental Ethics and Mercury, supra note 87; 60 Minutes, supra note 4 (“The FDA remains confident in the value of amalgams in dental care. It says it could ban them, but it won’t do that until it is satisfied there is a health risk.”).
  111. 60 Minutes, supra note 4.[T]he FDA’s dental division has been platooned full of American Dental Association people. The entire committee is made up of people from dental institutions, practicing dentists and people from the dental industry who make the dental materials. There is virtually no medical input or basic science input for medicine on that committee. [Thus], anything the ADA wants they pretty much get through the FDA. Id. at 9. (quoting Dr. Murray Vimy).
  112. Peterson, supra note 27 (citing Murray Vimy of the University of Calgary).
  113. See Voice of the People: Baa, baa, baa, Chicago Tribune, Aug. 29, 1990, section 1, at 15, col. 3 (“As a result of this alert journalism, I am confident that no dentist will ever again do a silver filling on a sheep.”). See also, Voice of the People: Silver Fillings, Chicago Tribune, Sept. 9, 1990, section 4, at 2, col. 3 (“Why then do you give so much exposure and implied credence in what happened to the kidneys of six sheep in Canada? … Would you call a test on six sheep in Canada significant?”).
  114. Richards, supra note 56. See also, infra note 179.
  115. Vimy, Boyd, Hopper & Lorscheider, Glomerular Filtration Impairment By Mercury Released From Dental “Silver” Fillings In Sheep, 33 The Physiologist A-94 (Abstracts) (Aug. 1990); Hahn, Kloiber, Leininger, Vimy & Lorscheider, Whole-Body Imaging Of The Distribution Of Mercury Released From Dental Fillings Into Monkey Tissues, 4 Federation Am. Societies For Experimental Biology J. 3256 (1990) (“This study clearly demonstrates that the phenomenon of high Hg accumulation in body tissues after dental amalgam placement which we previously reported in sheep (footnotes omitted) is not unique to that species, and is readily demonstrable in primates as well.” Id. at 3258-59).
  116. See Summers, Wireman, Vimy & Lorscheider, Increased Mercury Resistance In Monkey Gingival and Intestinal Bacterial Flora After Placement of Dental “Silver” Fillings, 33 The Physiologist A-116 (Abstracts) (Aug. 1990) (mercury was found to attack the primate immune system) [hereinafter Increased Mercury Resistance]; see also, 60 Minutes, supra note 4.
  117. Increased Mercury Resistance, supra note 116 at A-116.
  118. Lee, supra note 9.
  119. Id. (quoting bacteriologist Anne Summers of the University of Georgia).
  120. Drilling for Danger?, supra note 40.
  121. Hahn, Kloiber, Leininger, Vimy & Lorscheider, supra note 115, at 3256 (“The dental profession’s advocacy of silver amalgam as a stable tooth restorative material is not supported by these findings.”).
  122. Peterson, supra note 27 (quoting Murray Vimy of the University of Calgary).
  123. Peterson, supra note 27.
  124. OSHA to Begin Enforcing “Hazard” Rule, 19 Am. Dental A. News 1 (Aug. 1, 1988).
  125. Infra notes 127 and 134.
  126. See infra note 150.
  127. County Says Dentists Are Dumping Excess Mercury, supra note 25.
  128. Id.
  129. Id.
  130. Id.
  131. Id. “Mercury, which can kill as it attacks the central nervous system of animals, `accumulates in vertebrates.'” Id. (quoting Bruce Palmer of the Arizona Game & Fish Department).
  132. Id.
  133. 42 U.S.C. Sec. 9607 (as amended by the Superfund Amendments and Reauthorization Act of 1986, Pub. L. No. 99-499, 100 Stat. 1613 (1988)).
  134. EPA, Dentists Settle in Mercury Cleanup Case, 19 Am. Dental A. News 1 (Aug. 15, 1988) (Both sites required the removal of twelve hundred ten (1,210) tons of mercury contaminated soil).
  135. Id. The dentists settled with the EPA pursuant to 122(h) of Cercla, 42 U.S.C. Sec. 9622(h) (1988).
  136. U.S. v. Eugene L. Bourdeaudhui, Elsie Bourdeaudhui, Edward Battle, Benco Dental Supply Co., Inc., Ott Dental Supply Co., and Smith-Holden, Inc., A. Levanthal & Sons, Inc., Civ. No. H-88-354 (AHN) (D. Conn. June 3,1988), Dept. of Justice file No. 90-11-2-362, EPA Region I Site Numbers 74 & 76 [hereinafter Bourdeaudhui].
  137. Id. (Consent Decree, signed July 28, 1989); 1989 EPA Consent LEXIS 14, Civ. No. H-88-354 (AHN) (D. Conn. 1988) (Consent Decree), Dept. of Justice file No. 90-11-2-362, EPA Region I Site Numbers 74 & 76 (LEXIS, Envirn library, Cases file).
  138. Bourdeaudhui, supra note 136 (complaint at 4) (citing 42 U.S.C. Secs. 9602 & 42 U.S.C. 9601(14)) (1988) (emphasis added). For purposes of Sec. 107 of CERCLA, amalgam is a mercury compound, a zinc compound, a silver compound and a copper compound. Id. See 40 C.F.R. Sec. 302.4 at 930, 944, 955, 962 (1987). The U.S. also noted that mercury is a hazardous air pollutant under Sec. 112 of the Clean Air Act, 42 U.S.C. Sec. 7412 (1988), 40 C.F.R. Sec. 61.01 (1990), and a toxic pollutant under Sec. 307(a) of the Clean Water Act of 1977, 33 U.S.C. Sec.1317(a) (1988) and 40 C.F.R. Sec.401.15 (1990). Bourdeaudhui, supra note 136 (complaint at 4) (citing 33 U.S.C. Sec. 1317(a) (1988), 40 C.F.R. Sec. 401.15 (1990) (also listing mercury and compounds, silver and compounds, copper and compounds, zinc and compounds)). The EPA has reasoned that “`any substance that contains a listed hazardous substance is itself a hazardous substance.'” Court OKs ADA Appearance in Amalgam Case, 20 Am. Dental A. News 1 (Jan. 16, 1989).
  139. Bourdeaudhui supra note 136 (Motion to Appear, Introduce Evidence, File Brief and Make Oral Argument as Amicus Curiae). The ADA wrote:The issues involved in this action are of paramount importance to the members of the ADA as well to the general public since their resolution will have a vital impact on the general public and on the manner in which the members may practice their profession in the United States, in that the handling and recycling of dental amalgam is being challenged in the United States. Dental amalgam is the primary restorative material utilized by dentists for the restoration of the teeth of patients.Id. at 4. As part of its effort to establish the safety of amalgam fillings, the ADA reiterated its resolve that “Dental amalgam has been safely used in the United States for over 150 years and dates back several centuries in other countries.” Id.
  140. Id. See also, Court OKs ADA Appearance in Amalgam Case, supra note 138 (“In appearing as a friend of the court, the ADA is doing what it can to ensure that its position on the safety of scrap amalgam is made clear.”).
  141. EPA, Dentists Settle in Mercury Cleanup Case, supra note 134 (quoting Mary K. Logan, ADA associate general counsel). The ADA feared the case could set off a legal declaration that dental amalgam could be declared a hazardous substance by a federal court, as it clearly was by the EPA. “In a worst case scenario, scrap amalgam could be declared an environmental hazard, but that is the extent of it.” Id.
  142. Court OKs ADA Appearance in Amalgam Case, supra note 138.
  143. Id. (quoting Kenneth D. Walma, ADA legal affairs director,”That’s not a federal court talking,” said Mr. Walma. “That’s the EPA; the court has said nothing of the sort.”).
  144. See, supra note 137.
  145. Court OKs ADA Appearance in Amalgam Case, supra note 138.
  146. See supra note 137.
  147. Id. (Motion to Appear, Introduce Evidence, File Brief and Make Oral Argument as Amicus Curiae at 2).
  148. Id.
  149. Supra note 147.
  150. A new environmental hazard was recently identified in Britain as a result of the effects of burial funerals to cremation. Dr. Allan Mills, of Leicester University, says that poisonous mercury vapor is being released into the air from the dental fillings of the cremated. Mills, Mercury and Crematorium Chimneys, Nature (London) 615 (Aug. 16, 1990).
  151. One of the ADA’s “signs” as to “how to spot a quack” is whether a dentist “supports claims with articles published in obscure, pseudoscientific journals or the public media.” How to Spot a Quack, 115 J.A.D.A. 681 (1987). However, no definition of “pseudoscientific” was provided.
  152. See infra note 157.
  153. The ADA’s position is simple: Since there is no risk involved, informed consent is unnecessary. See 60 Minutes, supra note 4, at 9-10 (Dr. Heber Simmons, ADA spokesman).
  154. Kotler, Utility, Autonomy and Motive: A Descriptive Model of the Development of Tort Doctrine, 58 U. Cinn L. Rev. 1231, 1260 (1990) (citing Schloendorff v. Society of New York Hosp., 211 N.Y. 125, 105 N.E 92 (1914) (Cardozo, J.)). See also, Note, The Doctrine of Informed Consent Applied to Psychotherapy, 72 GEO. L.J. 1637, 1640 (1984) [hereinafter Doctorine] (footnotes omitted) (“The doctrine of informed consent is the means by which individuals are informed of, and may assert their preferences for, alternative forms of available medical treatment.”).
  155. Kotler, supra 154, at 1260 (quoting Schloendorff v. Society of New York Hosp., 211 N.Y. 125, 129-30, 105 N.E. 92, 93 (1914) (Cardozo, J.)).
  156. 154 Cal. App. 2d 560, 573-75, 317 P.2d 170, 181 (Dist. Ct. App. 1957).
  157. Id.
  158. Shultz, From Informed Consent to Patient Choice: A New Protected Interest, 95 Yale L.J. 219, 226-27 (1985) (footnote omitted).
  159. Kotler, supra note 154, at 1252 (quoting Shultz, From Informed Consent to Patient Choice: A New Protected Interest, 95 YALE L.J. 219, 280 (1985)).Doctors are universally conceded to be fiduciaries; as such they have special duties to serve their clients’ interests. Patients have been redefining their interests in the direction of more active participation in decision making. In the wake of such redefinition, the nature of fiduciary obligation must also change to stress more advising and less deciding. Id. at 279 (footnotes omitted).
  160. W. Keeton, R. Keeton, D. Dobbs & D. Owen, Prosser and Keeton on The Law of Torts (5th ed. 1984) 359 (footnotes omitted) (for example, dentists could be held liable for studies of which they are aware or those which, by reasonable diligence, should be aware). “The evidence is here, and [the public] should say that if it’s not reasonably safe… [it should not be put into a] child’s mouth.” 60 Minutes, supra note 4, at 10 (quoting Dr. Alfred Zamm, allergist & dermatologist).
  161. Bourdeaudhui, supra note 136 (Motion to Appear, Introduce Evidence, File Brief and Make Oral Argument as Amicus Curiae at 2).
  162. Peterson, supra note 27 (quoting ADA President R. Malcom Overbey).
  163. Shultz, supra note 158, at 226-27 (footnote omitted).
  164. Kotler, supra note 154, at 1252.
  165. Id.
  166. See supra note 159.
  167. Doctrine, supra note 154 at 1642. See Twerski & Cohen, Informed Decision Making and the Law of Torts: The Myth of Justiciable Causation, 1988 U. ILL. L.R. 607 (1988). See also, Choulos & Weiner, supra note 27. “The proof of proximate may be difficult, but in cases with clearly manifested injuries it is not impossible if expert testimony is up to standard on causation.” Id. at 15.
  168. Shultz, supra note 158, at 226-27 (footnote omitted).
  169. Comment, Informed Consent: Patient’s Right to Comprehend, 27 How. L.J. 975, 978 (1984) [hereinafter Informed Consent] (quoting Karp v. Cooley, 493 F.2d 408 (5th Cir. 1974), cert. den., 419 U.S. 845 (1974) (majority view)). See also, Shultz, supra note 158, at 248 (footnote omitted).
  170. Informed Consent, supra note 169, at 978.
  171. Id. at 982 (footnote omitted).
  172. Id. at 981 (footnotes omitted). See also, Shultz, supra note 158, at 226-27 (footnote omitted) (This standards requires the patient to establish that the nondisclosed information would not only have induced him, but any reasonable patient to withhold consent).
  173. Informed Consent, supra note 169, at 982 (footnote omitted).
  174. Id. at 982-83 (footnotes omitted).
  175. Id. at (citing Salis v. U.S., 522 F. Supp. 989 (M.D. Pa. 1981)). See supra note 50.
  176. See Comment, The Drug Manufacturer’s Duty to Warn — To Whom Does It Extend?, 13 FLA. ST. U. L. REV. 135, 156 (1985) [hereinafter Drug Manufacturer’s Duty (footnote omitted) (“In order for a product warning to be effective, the following criteria must be met: (1) the warning must be received; (2) the warning must be understood; and (3) the individual must act in accordance with the warning.”). See also, Dental Ethics and Mercury, supra note 87 (after recently banning the use of mercury recently in all interior latex paint products, the EPA now requires all latex exterior paint be clearly labeled as to its mercury content).
  177. Peterson, supra note 27.
  178. Drug Manufacturer’s Duty, supra note 176, at 156 (footnote omitted) (suggesting that since patients rarely receive proper warnings from doctors that a direct manufacturer-to-patient to warn in lay language might be a better way to inform patients). See also, Dental Ethics and Mercury, supra note 87 (the EDA contends dentists who fail to inform patients of mercury-laden fillings are acting unethically).
  179. David Kennedy, D.D.S., et al. v. American Dental Association, Civil Action No. 1-90 Civ. 1692 (N.D. Ohio 1990).
  180. Id. at 2 (complaint).
  181. Id.
  182. Id. at 4-7.
  183. Id. at 12.
  184. Id. at 12-13.
  185. Choulos & Weiner, supra note 27, at 13. “The prospect of punitive damages makes a potential offender take notice, particularly when the measure is a portion of corporate profits and has made corporate executives vulnerable to criticism from stockholders who face reduced dividends.” Id. at 13-14.
  186. Dental Ethics and Mercury, supra note 87.
  187. H.R.J. Res. 1001, 57th Leg., 1990 Colo. 1st Sess. (Proposed 1990 amendment to 12-35-103 Colo Rev. Stat Sec. 5 (1985 Repl. Vol.)) [hereinafter H.R.J. Res. 1001].(1.7) “Informed consent” means written consent given by a patient prior to any dental procedure or treatment which involves the placement or implant of mercury amalgam or any other dental prosthetic containing mercury, and which is obtained after the patient is sufficiently informed as to the procedures or treatment to be used and all associated risks which a reasonable patient would consider significant in making a decision of whether to undergo the procedure or treatment, including any special risks involved of which the dentist knows or should reasonably know.(2)… the use of amalgam or any other dental prosthetic containing mercury in the preparation and implant of dental fillings is expressly prohibited where prior written informed consent from the patient is not obtained…. A dentist shall be strictly liable for any injury which results from the placement of mercury amalgam into a patient where written informed consent is not obtained prior thereto. Id. (emphasis added).
  188. Id.(2)… No dentist shall be sanctioned, reprimanded, punished or otherwise prohibited from practicing dentistry by any entity or organization where the dentist has determined, within his or her professional judgment, that the removal and replacement of a mercury amalgam filling is reasonably necessary to restore or protect the patient’s health and safety, and where the dentist proceeds to remove and replace such filling after making this determination….Id. See also, Consent and Authorization, H.R.J. Res. 1001, 57th Leg., 1990 Colo. 1st Sess.
  189. See supra note 29.
  190. Supra note 187 (Commentary to proposed 1990 amendment to 12-35-103 Colo Rev. STAT Sec. 5 (1985 Repl. Vol.) at 1).Within the dental profession, studies have provided substantial scientific evidence that dental amalgam containing mercury can endanger the health and safety of patients who receive amalgam fillings…. At present, dental patients are not typically informed of the potential risks which exist when mercury amalgam is used for dental fillings. The proposed Act seeks to assure the health and safety of all dental patients by requiring dentists to give their patients basic information regarding the risks involved when mercury amalgam is used…. [Disclosures as to the potential risks of mercury amalgam] would undoubtedly be greatly appreciated by the patients, and further strengthen the trust and confidence that the patient has in their dentist. Id.
  191. Id.
  192. Id.
  193. H.R.J. Res. 1001, supra note 187.WHEREAS it is a common dental practice in the state to use an amalgam of materials for dental fillings; andWHEREAS this dental amalgam is thought by most persons to be made only of silver, but its composition is actually 50 percent mercury; andWHEREAS some studies have shown that toxic mercury vapors can leak from the fillings into the patient’s blood system and lead to mercury poisoning, particularly in chemically sensitive or allergic persons; andWHEREAS dental patients should have the right to choose which materials are used for their dental fillings, but they often lack basic information from the dentist that would help them make an informed choice; Resolved… dentists will inform their patients that:a. mercury is contained in most dental filling material;

    b. mercury in fillings can have toxic effects on some persons;

    c. there are alternative materials that could be used for dental fillings that could have other effects on the person; and

    d. they have a right to insist that an alternative material be used. Id.

  194. Dentist Says Silver Fillings Bad, UPI, Jun. 8, 1983 (AM cycle).
  195. A Wolf in Legislative Clothing, 120 J.A.D.A. 397 (1990) (specifically referring to proposed legislation in Alaska).
  196. S. Res. 12, 16th Leg., 1989 Alaska 1st Sess.; see also, 60 Minutes, supra note 4. “When I measured mercury coming off of fillings, that was `reasonable doubt’ in my mind.” Id. at 3 (quoting Dr. Murray Vimy). “There’s a lot of things we don’t know, but I do know that it’s not safe to put something in somebody’s mouth that has a question.” Id. at 7 (quoting Dr. Alfred Zann).
  197. S. Res. 12, 16th Leg., 1989 Alaska 1st Sess.
  198. Id.
  199. A Wolf in Legislative Clothing, supra note 195 (specifically referring to proposed legislation in Alaska).
  200. H.R. Res. 1084, 86th Leg., 1989 Ill. 1st Sess. (Offered by Rep. Cowlishaw; Adopted on November, 1, 1989. Signed Michael J. Madigan, Speaker of the House and John F. O’Brien, Clerk of the House); reprinted in 6 Bio-Probe Newsletter 3 (Jan. 1990). WHEREAS, It is a common dental practice in Illinois to use an amalgam of materials for dental fillings; and WHEREAS, This dental amalgam, thought by the public to be made only of silver, is actually 50% mercury; and WHEREAS, Studies have shown that toxic mercury vapors can leak from fillings into the blood system and cause serious health problems, particularly in persons with allergies or chemical sensitivities; andWHEREAS, Dental patients often lack information that would enable them to avoid having mercury used for their fillings; therefore be itResolved, by the House of Representatives of the Eighty-Sixth General Assembly of the State of Illinois, that this body hereby requests that the Illinois Department of Public Health review the studies that have examined the health risks of mercury in dental fillings and report to the General Assembly by March 1, 1990, its finding about such risks as well as its recommendations for providing a means by which dental patients may be informed of the findings and of the alternatives to mercury content in fillings when seeking dental treatment; and be it furtherResolved, That a copy of this preamble and resolution be presented to the Director of the Illinois Department of Public Health. Id.
  201. A Wolf in Legislative Clothing, supra note 195 (referring to Alaska and North Carolina).
  202. Choulos & Weiner, supra note 27, at 13.
  203. See Drilling for Danger?, supra note 40 (“Over the last 10 years, researchers have shown that mercury escapes from fillings and winds up in body tissues”).
  204. Shultz, supra note 158, at 296 (footnote omitted).
  205. While the ADA claims that dental amalgam is safe and effective, it also “believes that dentists should choose the best possible restorative material for each patient on an individual basis. The professional judgment of the dentist and the desires of the patient should be the foundation on which that choice is based.” Special Report, supra note 3, at 398. But see International Academy of Oral medicine and Toxicology, supra note 4, at 9 (suggesting that the ADA Principals of Ethics and Code of Professional Conduct are in conflict because they specifically disapprove of informing patients of the dangers of amalgam fillings, while placing a duty on dentists to report investigations leading to public health threats); 60 Minutes, supra note 4, at 6 (Dr. Murray Vimy says the effect of the ADA’s position that informing patients of the dangers of amalgam is unethical infringes upon “the Constitutional rights of dentists and the rights of patients. [Patients] no longer have freedom of choice and [dentists] no longer have freedom of expression.”); supra note 86.
  206. Supra note 29.
  207. See supra note 147.
  208. H. Queen, supra note 1, at 24.In the U.S., because of the legal aspect, dental authorities who today must set guidelines of acceptable dental protocol may be reluctant to speak out against the use of mercury when such action is warranted. They may fear that dentists who have followed their previous guidelines will become liable…. An extension of this concern may also affect research. Whatever progress is made in getting closer to the truth would most likely be met with a great deal of resistance.Id. (emphasis added).
  209. International Academy of Oral medicine and Toxicology, supra note 4 at 6.
  210. Supra note 179.
  211. Kotler, supra note 155, at 1260 (citing Schloendorff v. Society of New York Hosp., 211 N.Y. 125, 105 N.E. 92 (1914) (Cardozo, J.)).
  212. I. Mjör, supra note 17, at 24 (because “individual case reports often prevail as evidence… the problem should be dealt with on an individual basis rather than by prohibiting the use of a serviceable dental material.”).
  213. See F. Royal, supra note 47 at 210.
  214. Drilling for Danger ?, supra note 40 (emphasis added); see supra note 27.
  215. Choulos & Weiner, supra note 27 at 14.
  216. Supra note 179.
  217. Choulos & Weiner, supra note 27 at 14.
  218. Id. at 15.
  219. Editor’s note: Readers who are personally concerned about this problem should see The Mercury in Your Mouth, 56 Consumer Reports 316 (1991) — published just before this issue went to press.

Copyright 1991 by the Franklin Pierce Law Center; Michael A. Royal

Reprinted with permission.


Dentists Sue State Licensing Boards

Over First Amendment Rights

In May 2001, five dentists and seven patients filed a suit in federal court against state regulators claiming injury from the mercury in their fillings. The plaintiffs argue that dental regulators use “control of dental licenses to punish, or to threaten punishment of, dentists who criticize mercury amalgam,” violating the dentists’ First Amendment rights. In 1999, for example, the suit claims that the Maryland Board of Dental Examiners ordered dentist Bill DeLong to stop testing his patients to determine whether mercury vapor was coming off their fillings. (The case was eventually dropped.)

Plaintiffs want the court to order licensing boards to stop enforcing any policy that “prevents, limits, or intimidates dentists” from discussing the controversy or advocating “mercury-free” dentistry. The suit also seeks certification as a defendants’ class action naming 50 of the country’s 52 licensing agencies.

The dental establishment maintains that some dentists have used the controversy over mercury’s safety to encourage patients to remove amalgam fillings and replace them with more expensive materials such as gold, porcelain and a tooth-colored resin composite. Resin, the least expensive alternative, costs as much as 25% more than fillings containing mercury.

J. Rodway Mackert Jr., a professor at the Medical College of Georgia who is an ADA spokesman. says that discussing mercury when patients are in the dentist’s chair would be a disservice to them. “If you have one side claiming it isn’t safe, that doesn’t mean that side is right,” he says.

Nevertheless, state legislatures in New York and Maine are debating bills that would require dentists to disclose to patients the makeup of their fillings. New York Assemblyman Richard Brodsky’s bill would also ban dentists from filling cavities in pregnant women and children with mercury. A Vermont bill would require dental offices to track how much mercury they use in fillings. And California’s dental board is considering spelling out the pros and cons of different fillings in a consumer fact sheet.

Meanwhile, the Maryland board is proposing a new rule that states that removing “serviceable mercury amalgam restorations” is unprofessional without informed consent that includes telling the patient that “there are no verifiable systemic health benefits resulting from the removal.”

Source: The Wall Street Journal


Dental Amalgam

Use and Benefits

September 2001—Dental amalgam, in widespread use for over 150 years, is one of the oldest materials used in oral health care. Its use extends beyond that of most drugs, and is predated in dentistry only by the use of gold. Dental amalgam is the end result of mixing approximately equal parts of elemental liquid mercury (43 to 54 percent) and an alloy powder (57 to 46 percent) composed of silver, tin, copper, and sometimes smaller amounts of zinc, palladium, or indium.

Because of a general decline of dental caries among school children and young adults, the use of dental amalgam began to decrease in the 1970s. There are also changes in patterns of dental caries, largely the result of topical and systemic fluoride, sealant use, improved oral hygiene practices and products and possibly dietary modifications. In 1990, over 200 million restorative procedures were provided in the United States; of these, dental amalgam accounted for roughly 96 million, a 38 percent reduction since 1979. This trend is expected to continue.

There are also reports that carious lesions today are generally smaller, easier to treat, and managed by more conservative treatment that retains tooth structure. Because of this decrease in the frequency and size of dental caries, there has been a relative increase in the use of alternative dental restorative materials. The most commonly used and less expensive of the alternative materials, however, cannot be used for large lesions and need more frequent replacement. Also, there are currently many serviceable dental amalgam restorations that will need replacing in the future. Approximately 70 percent of the restorations placed annually are replacements. Most of these replacements will require amalgam or other metallic materials, because composite materials often lack sufficient strength or durability to be considered adequate substitutes.

Today, dental amalgam is used in the following situations:

  • in individuals of all ages,
  • in stress-bearing areas and in small-to-moderate sized cavities in the posterior teeth,
  • when there is severe destruction of tooth structure and cost is an overriding consideration,
  • as a foundation for cast-metal, metal-ceramic, and ceramic restorations,
  • when patient commitment to personal oral hygiene is poor,
  • when moisture control is problematic with patients,
  • when cost is an overriding patient concern.

It is not used when:

  • esthetics are important, such as in the anterior teeth and in lingual endodontic-access (root canal) restorations of the anterior teeth,
  • patients have a history of allergy to mercury or other amalgam components,
  • a large restoration is needed and the cost of other restorative materials is not a significant factor in the treatment decision.

Highlights of the Report on Dental Amalgam

Dental amalgam has been used as a dental restorative material for over 150 years. Amalgam remains popular because it is strong, durable and relatively inexpensive. Roughly 200 million restorative procedures performed in 1990 used amalgam. Nonetheless, amalgam use is declining because the incidence of caries is decreasing and because improved substitute materials are now available for certain applications.

Composition of Amalgam Alloy

Currently used alloys are composed of silver (40 to 70 percent), tin (12 to 30 percent) and copper (12 to 30 percent). They also may include indium (0 to 4 percent), palladium (0.5 percent) and zinc (up to 1 percent). The zinc improves the clinical performance of the amalgam. Although the role of zinc in enhancing clinical performance is not well-understood, it may be that the zinc inhibits corrosion. Although some researchers and clinicians believe that zinc causes delayed expansion of amalgam if contaminated with moisture, some research on high-copper amalgam indicates otherwise. Selection of a nonzinc alloy to avoid expansion of the amalgam is not indicated.

The alloy is mixed with mercury (43 to 50.5 percent by weight) to form the amalgam. The amalgam may be supplied as lathe-cut irregular particles, small spheres or a combination of the two. Handling characteristics of the amalgam vary depending on formulation and particle size and shape. The clinical performance of various formulations and particle sizes and shapes does not differ significantly.

Spherical alloys are less resistant to condensation, so it would seem that they should adapt easier to cavity walls. However, restorations made of spherical alloys exhibit greater microleakage because of poorer adaptation to the cavity and/or shrinkage of the amalgam as it sets. Thorough lateral condensation during placement will help to overcome this problem.

Dental amalgam, an intermetallic compound, contains lemental mercury that is emitted in minute amounts as vapor. Because vapor emitting from amalgam restorations can be absorbed by the patient through inhalation, ingestion, or other means, concerns have been raised about possible toxicity. At present, there is scant evidence that the health of the vast majority of people with amalgam is compromised, nor that removing amalgam fillings has a beneficial effect on health. It also is recognized that a total conversion from dental amalgam to alternative materials would cause a significant increase in U.S. health care costs. Nonetheless, the possibility that this material, as well as currently available alternatives, could pose health risks cannot be totally ruled out because of the paucity of definitive human studies.

Given the limitations of existing scientific data, a research program should be designed and implemented to fill as many gaps as possible in current knowledge about the potential long-term biological effects of dental amalgam and alternative restorative materials. The PHS should be a leader in this effort.

The PHS should also educate dental personnel and consumers about the risk and benefits of dental amalgam. An educational program should include information on all restorative materials to help dentists and their patients make informed dental treatment decisions, and encourage dental care providers to report adverse reactions. Such a program should promote the use of preventive measures such as fluoride and dental sealants to prevent caries and thus further reduce the need for dental restorations.

To exert greater control over dental amalgam use, the FDA should regulate elemental mercury and dental alloy as a single product. To help dentists identify patients who may exhibit allergic hypersensitivity to all restorative materials, including dental amalgam, FDA should require manufacturers to disclose the ingredients of these materials in product labeling.

Sweden, Denmark, and Germany have proposed restrictions on dental amalgam use to diminish both human exposure to and environmental release of mercury and not because of any documented health effects associated with exposure to dental amalgam.

The U.S. Public Health Service believes it is inappropriate at this time to recommend any restrictions on the use of dental amalgam, for several reasons. First, current scientific evidence does not show that exposure to mercury from amalgam restorations poses a 
serious health risk in humans, except for an exceedingly small number of allergic reactions. Second, there is insufficient evidence to assure the public that components of alternative restorative materials have fewer potential health effects than dental amalgam including allergic-type reactions. Third, there are significant efforts underway in the U.S. to reduce the amount of mercury in the environment. And finally, as stated previously, amalgam use is declining due to a lessening of the incidence of dental caries and the increasing use of alternative materials.

Source: Division of Oral Health Centers for Disease Control and Prevention, Sept. 2001


Consumer Update: Dental Amalgams

FDA and other organizations of the U.S. Public Health Service (USPHS) continue to investigate the safety of amalgams used in dental restorations (fillings). However, no valid scientific evidence has ever shown that amalgams cause harm to patients with dental restorations, except in the rare case of allergy.

The safety of dental amalgams has been reviewed extensively over the past ten years, both nationally and internationally. In 1994, an international conference of health officials concluded there is no scientific evidence that dental amalgam presents a significant health hazard to the general population, although a small number of patients had mild, temporary allergic reactions. The World Health Organization (WHO), in March 1997, reached a similar conclusion. They wrote: “Dental amalgam restorations are considered safe, but components of amalgam and other dental restorative materials may, in rare instances, cause local side effects or allergic reactions. The small amount of mercury released from amalgam restorations, especially during placement and removal, has not been shown to cause any other adverse health effects.” Similar conclusions were reached by the USPHS, the European Commission, the National Board of Health and Welfare in Sweden, the New Zealand Ministry of Health, Health Canada and the province of Quebec.

In January 1993, the USPHS published a broad scientific report about the safety and use of dental amalgam and other materials commonly used to fill dental cavities. These conclusions were reaffirmed by USPHS in 1995 and 1997. Since then, the National Institutes of Health (NIH), the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA) have continued to study the issue. The National Institute of Dental & Craniofacial Research at NIH has also provided money to study the safety of dental amalgams and to develop non-mercury alternatives. This effort includes research and clinical studies of dental amalgam use in children. These studies are ongoing and will require several years of follow-up in order to detect any subtle and long-range health effects if they are present.

Also, USPHS scientists analyzed about 175 peer-reviewed studies submitted in support of three citizen petitions received by FDA after the 1993 report. They concluded that data in these studies did not support claims that individuals with dental amalgam restorations will experience problems, including neurologic, renal or developmental effects, except for rare allergic or hypersensitivity reactions.

Although there is international agreement that the scientific data do not confirm the presence of a significant health hazard, several countries restrict the use of dental amalgams or have recommended limitations on their use. Some manufacturers now include these “contraindications” (against using) in their labeling of dental amalgams sold in those countries. If a manufacturer wishes to make a similar labeling change in its dental amalgam sold in the United States, FDA will require the manufacturer to submit a new marketing application with data supporting the change.

FDA plans to uniformly regulate dental mercury, amalgam alloy, and pre-encapsulated dental amalgam. To reduce allergic reactions from restorative materials, FDA will propose in labeling guidance that the product’s labeling list the ingredients in descending order of weight by percentage and include lot numbers, appropriate warnings and precautions, handling instructions and expiration dating. The labeling guidance will be most useful with new restorative materials.

While research, regulatory changes, and educational efforts are underway, the use of dental amalgams in the U.S. is declining. Pediatric dentists, in particular, are using resin (plastic); tooth-colored materials that are bonded to the tooth may release fluoride and are mercury-free. Other reasons for the decline in amalgam use include increasing use of sealants and community fluoridation, an expanding selection of fluoride-containing dental products, improved oral hygiene practices, and greater access to dental care.

For the foreseeable future, dental amalgam will continue to be used as a restorative material. The USPHS will continue gathering data about possible risks of dental amalgams and other restorative products and pursuing new methods of dental treatment and oral health. As an important part of this plan, USPHS will continue working with the dental profession to bring about changes in the delivery of oral healthcare based on valid scientific research.

Predictions for the Future of Dental Amalgam

The prediction that amalgam would not last until the end of the 20th century is not proving to be accurate. Its unesthetic appearance, its inability to bond to the tooth, concerns about mercury and the versatility of other materials have not led to the elimination of this inexpensive and durable material. As other materials and techniques improve, the use of amalgam will likely continue to diminish, and it will eventually disappear from the scene.

One report of dental insurance statistics shows a decline in the use of amalgam for posterior direct restorations from 85 percent in 1988 to 58 percent in 1997 (Maxwell H. Anderson, D.D.S., M.S., M.Ed., dental director, Washington Dental Service, Delta Dental, written and oral communication, May 21, 1998). Yet, amalgam continues to be the best 
bargain in the restorative armamentarium because of its durability and technique insensitivity

According to a report in the Journal of the American Dental Association, amalgam will probably disappear eventually, but its disappearance will be brought about by a better and more esthetic material, rather than by concerns over health hazards. When it does disappear’ it will have served dentistry and patients well for more than 160 years.


Dentists Are The Biggest Mercury Polluters, A New Study Finds

A new report shows that dentists are the largest single source of mercury pollution in waste water funneled into the nation’s treatment plants.

Coal-fired power plants are notorious for being the biggest source of mercury pollution in the air, which falls into streams and rivers. Many dentists flush it down their drains and it goes directly into waste-water treatment plants, which do not effectively filter it from the water.

In 1985 dental facilities used 3% of all the mercury used nationwide. Last year, although dentists used less mercury their use accounted for 20% of all uses. Only two other industries– wiring devices and switches and chloralkali–used more.

A 2001 study by the Assn. of Metropolitan Sewerage Agencies evaluated seven major municipal waste-water treatment plants and determined that dental uses were “by far” the greatest contributors to the mercury reaching their facilities. They were responsible for 40% of the load, three times more than the next largest contributor.

Several other countries regulate releases of dental mercury. In Canada, a new standard requires dentists to trap the pieces of filling before they go down the drain. The goal is to reduce releases by 95% by 2005.

In May, the New Hampshire Legislature became the first in the nation to pass legislation governing disposal methods for dental mercury.

Source: Los Angeles, Times, May 2002.  Mercury Policy Project.


Dental Materials Fact Sheet

Attention: California Dentist
The Dental Materials Fact Sheet (DMFS) was sent to all licentiates on October 31, 2001, as a 4-page pull-out. Business & Professions Code section 1648.15, effective January 1, 2002, requires the following

  1. The dentist must provide the fact sheet to every new patient and to patients of record before performing dental restoration work. The dentist needs to provide the fact sheet to each patient only once.
  2. The patient must sign an acknowledgment of receipt of the fact sheet and a copy of the acknowledgment must be placed in the patient’s dental record.
  3. If the Board updates the fact sheet, the updated fact sheet must be given to patients in this same way.
  4. The dentist must also provide the fact sheet to the patient upon request.
  5. The dentist is responsible for copying the fact sheet for distribution. The fact sheet is currently available only in English.

The dentist is responsible for copying the fact sheet for distribution. The fact sheet is currently available only in English. A Spanish version will be available sometime in May 2002.

Note: Suggested wording for “Patient Release Form” – “I have received a copy of the Dental Materials Fact Sheet as required by law” – Provide a line on the bottom of the label for signature and date . Or you may have a stamp made with appropriate wording, stamp the patient record and obtain a signature and date.

If you have not received your copy of the DMFS, or have questions, please call (916) 263-2300, ext. 2309 or go the Board’s website @ and click on News and Information.


Dental Materials Fact Sheet (DMFS)–Frequently Asked Questions

What is the Dental Materials Fact Sheet?

In 1992, the Legislature passed a law requiring the Dental Board to develop and distribute a fact sheet describing and comparing the various types of dental restorative materials used in repairing a patient’s teeth. The fact sheet is intended to encourage discussion between the patient and dentist regarding the materials and options. An independent consultant developed the fact sheet using a number of peer-reviewed scientific articles.

What if I disagree with the DMFS, do I still have to provide it to my patients?

Yes, SB 134, signed by Governor Davis in October 2001, requires each dentist to provide a copy of the DMFS to new patients or patients of record prior to any restorative work. The dentist must obtain a signed acknowledgment that the patient has received the fact sheet. The acknowledgment must be placed in the patient’s record. The suggested wording for the release form is “I have received a copy of the Dental Materials

Fact Sheet dated October 2001.” Provide space below for a signature line and date. Some of the dental societies are offering a pre-inked stamp with the proper language for a small fee. Call your local dental society to request the order form.

I don’t place amalgams, or I do only orthodontics –am I exempt?

No _ The law specifically states the DMFS should be provided prior to the performance of dental restoration work. This includes fillings, including amalgams, composites, crowns, bridges, onlays and veneers.

The majority of my patients are Hispanic. Is the DMFS going to be provided in Spanish or any other language?

Currently, the DMFS is available only in English. However, the Dental Board is translating the fact sheet into Spanish. The Spanish version should be available in May.

If your practice requires the DMFS in Spanish, please call Oralia Moya at extension 2328 for a copy. Meanwhile, you will have to explain dental materials options to the patient in the same way you would communicate to obtain patient history.

For further information, you may call (916) 263-2300, ext.2309.


Dental Materials Fact Sheet

As required by Chapter 801, Statutes of 1992, the Dental Board of California has prepared this fact sheet to summarize information on the most frequently used restorative dental materials. Information on this fact sheet is intended to encourage discussion between the patient and dentist regarding the selection of dental materials best suited for the patient’s dental needs. It is not intended to be a complete guide to dental materials science.

The most frequently used materials in restorative dentistry are amalgam, composite resin, glass ionomer cement, resin-ionomer cement, porcelain (ceramic), porcelain (fused-to-metal), gold alloys (noble) and nickel or cobalt-chrome (base-metal) alloys. Each material has its own advantages and disadvantages, benefits and risks. These and other relevant factors are compared in the attached matrix titled “Comparisons of Restorative Dental Materials.” A “Glossary of Terms” is also attached to assist the reader in understanding the terms used.

The statements made are supported by relevant, credible dental research published mainly between 1993-2001. In some cases, where contemporary research is sparse, we have indicated our best perceptions based upon information that predates 1993.

The reader should be aware that the outcome of dental treatment or durability of a restoration is not solely a function of the material from which the restoration was made.

The durability of any restoration is influenced by the dentist’s technique when placing the restoration, the ancillary materials used in the procedure, and the patient’s cooperation during the procedure. Following restoration of the teeth, the longevity of the restoration will be strongly influenced by the patient’s compliance with dental hygiene and home care, the diet and chewing habits.

Both the public and the dental profession are concerned about the safety of dental treatment and any potential health risks that might be associated with the materials used to restore the teeth. All materials commonly used (and listed in this fact sheet) have been shown – through laboratory and clinical research, as well as through extensive clinical use– to be safe and effective for the general population. The presence of these materials in the teeth does not cause adverse health problems for the majority of the population.

There exists a diversity of various scientific opinions regarding the safety of mercury dental amalgams. The research literature in peer-reviewed scientific journals suggests that otherwise healthy women, children and diabetics are not at increased risk for exposure to mercury from dental amalgams. Although there are various opinions with regard to mercury risk in pregnancy, diabetes, and children, these opinions are not scientifically conclusive and therefore the dentist may want to discuss these opinions with patients. There is no research evidence that suggests pregnant women, diabetics and children are at increased health risk from dental amalgam fillings in their mouth.

A recent study reported in the JADA factors in a reduced tolerance (1/50th of the WHO safe limit) for exposure in calculating the amount of mercury that might be taken in from dental fillings. This level falls below the established safe limits for exposure to a low concentration of mercury or any other released component from a dental restorative material. Thus, while these sub-populations may be perceived to be at increased health risk from exposure to dental restorative materials, the scientific evidence does not support that claim. However, there are individuals who may be susceptible to sensitivity, allergic or adverse reactions to selected materials. As with all dental materials, the risks and benefits should be discussed with the patient, especially with those in susceptible populations.

There are differences between dental materials and the individual elements or components that compose these materials. For example, dental amalgam filling material is composed mainly of mercury (43-54%) and varying percentages of silver, tin, and copper (46-57%). It should be noted that elemental mercury is listed on the Proposition 65 list of known toxins and carcinogens. Like all materials in our environment, each of these elements by itself is toxic at some level of concentration if it is taken into the body. When these elements are mixed together, they react chemically to form a crystalline metal alloy. Small amounts of free mercury may be released from amalgam fillings over time and can be detected in bodily fluids and expired air. The important question is whether any free mercury is present in sufficient levels to pose a health risk. Toxicity of any substance is related to dose, and doses of mercury or any other element that may be released from dental amalgam fillings falls far below the established safe levels as stated in the 1999 US Health and Human Service Toxicological Profile for Mercury Update.

All dental restorative materials (as well as all materials that we come in contact with in our daily life) have the potential to elicit allergic reactions in hypersensitive individuals. These must be assessed on a case-by-case basis, and susceptible individuals should avoid contact with allergenic materials. Documented reports of allergic reactions to dental amalgam exist (usually manifested by transient skin rashes in individuals who have come into contact with the material), but they are atypical. Documented reports of toxicity to dental amalgam exist, but they are rare. There have been anecdotal reports of toxicity to dental amalgam and as with all dental materials risks and benefits of dental amalgam should be discussed with the patient, especially with those in susceptible populations.

Composite resins are the preferred alternative to amalgam in many cases. They have a long history of biocompatibility and safety. Composite resins are composed of a variety of complex inorganic and organic compounds, any of which might provoke allergic response in susceptible individuals. Reports of such sensitivity are atypical. However, there are individuals who may be susceptible to sensitivity, allergic or adverse reactions to composite resin restorations. The risks and benefits of all dental materials should be discussed with the patient, especially with those in susceptible populations.

Other dental materials that have elicited significant concern among dentists are nickel-chromium-beryllium alloys used predominantly for crowns and bridges. Approximately 10% of the female population is alleged to be allergic to nickel. 2 The incidence of allergic response to dental restorations made from nickel alloys is surprisingly rare. However, when a patient has a positive history of confirmed nickel allergy, or when such hypersensitivity to dental restorations is suspected, alternative metal alloys may be used. Discussion with the patient of the risks and benefits of these materials is indicated.

1 . Dental Amalgam: A scientific review and recommended public health service strategy for research, education and regulation, Dept. of Health and Human Services, Public Health Service, January 1993.

2. Merck Index 1983. Tenth Edition, M Narsha Windhol z, (ed).

Adopted by the Board on October 17, 2001

Comparisons of Direct Restorative Dental Materials




General description Self-hardening mixture in varying percentages of a liquid mercury and silver-tin alloy powder. Mixture of powdered glass and plastic resin; self-hardening or hardened by exposure to blue light. Self-hardening mixture of glass and organic acid. Mixture of glass and resin polymer and organic acid; self hardening by exposure to blue light.
Principal uses Fillings; sometimes for replacing portions of broken teeth. Fillings, inlays, veneers, partial and complete crowns; sometimes for replacing portions of broken teeth. Small fillings; cementing metal and porcelain/ metal crowns, liners, temporary restorations. Small fillings; cementing metal and porcelain/metal crowns, and liners.
Resistance to further decay High; self-sealing characteristic helps resist recurrent decay; but recurrent decay around amalgam is difficult to detect in its early stages. Moderate; recurrent decay is easily detected in early stages. Low-moderate; some resistance to decay may be imparted through fluoride release. Low-moderate; some resistance to decay may be imparted through fluoride release.
Estimated durability (permanent teeth) Durable Strong, durable. Non-stress bearing crown cement. Non-stress bearing crown cement.
Relative amount of tooth preserved Fair; requires removal of healthy tooth to be mechanically retained; no adhesive bond of amalgam to the tooth. Excellent; bonds adhesively to healthy enamel and dentin. Excellent; bonds adhesively to healthy enamel and dentin. Excellent; bonds adhesively to healthy enamel and dentin.
Resistance to surface wear Low similar to dental enamel; brittle metal. May wear slightly faster than dental enamel. Poor in stress-bearing applications. Fair in non- stress bearing applications. Poor in stress-bearing applications; good in non- stress bearing applications.
Resistance to fracture Amalgam may fracture under stress; tooth around filling may fracture before the amalgam does. Good resistance to fracture. Brittle; low resistance to fracture but not recommended for stress-bearing restorations. Tougher than glass ionomer; recommended for stress-bearing restorations in adults.
Resistance to leakage Good; self-sealing by surface corrosion; margins may chip over time. Good if bonded to enamel; may show leakage over time when bonded to dentin; does not corrode. Moderate; tends to crack over time. Good; adhesively bonds to resin, enamel dentine; post-insertion expansion may help seal the margins.
Resistance to occlusal stress High; but lack of adhesion may weaken the remaining tooth. Good to excellent depending upon product used. Poor; not recommended for stress-bearing restorations. Moderate; not recommended to restore biting surfaces of adults; suitable for short-term primary teeth restorations.
Toxicity Generally safe; occasional allergic reactions to metal components. However amalgams contain mercury. Mercury in its elemental form is toxic and as such is listed on prop 65. Concerns about trace chemical release are not supported by research studies. Safe; no known toxicity documented. Contains some compounds listed on prop 65. No known incompatibilities. Safe; no known toxicity documented. No known incompatibilities. Safe; no known toxicity documented.
Allergic or adverse reactions Rare; recommended that dentist evaluate patient to rule out metal allergies. No documentation for allergic reactions was found. No documentation for allergic reactions was found. Progressive roughening of the surface may predispose to plaque accumulation and periodontal disease. No known documented allergic reactions; surface may roughen slightly over time; predisposing to plaque accumulation and periodontal disease if the material contacts the gingival tissue.
Susceptibility to post-operative sensitivity Minimal; high thermal conductivity may promote temporary sensitivity to hot and cold; contact with other metals may cause occasional and transient galvanic response. Moderate; material is sensitive to dentist’s technique; material shrinks slightly when hardened, and a poor seal may lead to bacterial leakage, recurrent decay and tooth hypersensitivity. Low; material seals well and does not irritate pulp. Low; material seals well and does not irritate pulp.
Esthetics (Appearance) Very poor; not tooth colored: initially silver-gray, gets darker, becoming black as it corrodes. May stain teeth dark brown or black over time. Excellent; often indistinguishable from natural tooth. Good; tooth colored, varies in translucency. Very good; more translucency than glass ionomer.
Frequency of repair or replacement Low; replacement is usually due to fracture of the filling or the surrounding tooth. Low-moderate; durable material hardens rapidly; some composite materials show more rapid wear than amalgam. Replacement is usually due to marginal leakage. Moderate; slowly dissolves in mouth; easily dislodged. Moderate; more resistant to dissolving than glass ionomer, but less than composite resin.
Relative costs to patient Low, relatively inexpensive; actual cost of fillings depends upon their size. Moderate; higher than amalgam fillings; actual cost of fillings depends upon their size; veneers & crowns cost more. Moderate; similar to composite resin (not used for veneers and crowns). Moderate; similar to composite resin (not used for veneers and crowns).
Number of visits required Single visit (polishing may require a second visit). Single visit for fillings; 2+ visits for indirect inlays, veneers and crowns. Single visit. Single visit.




General description Glass-like material formed into fillings and crowns using models of the prepared teeth. Glass-like material that is “enameled” onto metal shells. Used for crowns and fixed-bridges. Mixtures of gold, copper and other metals used mainly for crowns and fixed bridges. Mixtures of nickel, chromium.
Principal uses Inlays, veneers, crowns and fixed-bridges. Crowns and fixed-bridges. Cast crowns and fixed bridges; some partial denture frameworks. Crowns and fixed bridges; most partial denture frameworks.
Resistance to further decay Good, if the restoration fits well. Good, if the restoration fits well. Good if the restoration fits well. Good if the restoration fits well.
Estimated durability (permanent teeth) Moderate; brittle material that may fracture under high biting forces. Not recommended for posterior (molar) teeth. Very good. Less susceptible to fracture due to the metal substructure. Excellent. Does not fracture under stress; does not corrode in the mouth. Excellent. Does not fracture under stress; does not corrode in the mouth.
Relative amount of tooth preserved Good – moderate. Little removal of natural tooth is necessary for veneers; more for crowns since strength is related to its bulk. Moderate-high. More tooth must be removed to permit the metal to accompany the porcelain. Good. A strong material that requires removal of a thin outside layer of the tooth. Good. A strong material that requires removal of a thin outside layer of the tooth.
Resistance to surface wear Resistant to surface wear; but abrasive to opposing teeth. Resistant to surface wear; permits either metal or porcelain on the biting surface of crowns and bridges. Similar hardness to natural enamel; does not abrade opposing teeth. Harder than natural enamel but minimally abrasive to opposing natural teeth; does not fracture in bulk.


Glossary of Terms

General description–Brief statement of the composition and behavior of the dental material

Principal uses–The types of dental restorations that are made from this material.

Resistance to further decay –The general ability of the material to prevent decay around it.

Longevity/durability – The probable average length of time before the material will have to be replaced. (This will depend upon many factors unrelated to the material such as biting habits of the patient, the diet, the strength of the patient’s bite, oral hygiene, etc.)

Conservation of tooth structure – A general measure of how much tooth needs to be removed in order to place and retain the material.

Surface wear/fracture resistance – A general measure of how well the material holds up over time under the forces of biting, grinding, clenching, etc.

Marginal integrity (leakage) – An indication of the ability of the material to seal the interface between the restoration and the tooth, thereby helping to prevent sensitivity and new decay.

Resistance to occlusal stress – The ability of the material to survive heavy biting forces over time.

Biocompatibility – The effect, if any, of the material on the general overall health of the patient.

Allergic or adverse reactions – Possible systemic or localized reactions of the skin, gums and other tissues to the material.

Toxicity – An indication of the ability of the material to interfere with normal physiologic processes beyond the mouth.

Susceptibility to sensitivity – An indication of the probability that the restored teeth may be sensitive of stimuli (heat, cold, sweet, pressure) after the material is placed in them.

Esthetics – An indication of the degree to which the material resembles natural teeth.

Frequency of repair or replacement –An indication of the expected longevity of the restoration made from this material.

Relative cost – A qualitative indication of what one would pay for a restoration made from this material compared to all the rest.

Number of visits required – How many times a patient would usually have to go to the dentist’s office in order to get a restoration made from this material.

Dental amalgam – Filling material which is composed mainly of mercury (43-54%) and varying percentages of silver, tin, and copper (46-57%).


Position of the Academy of General Dentistry

What is dental amalgam?

Most people recognize dental amalgams as silver fillings. Dental amalgam is a mixture of mercury, and an alloy of silver, tin and copper. Mercury makes up about 45-50 percent of the compound. Mercury is used to bind the metals together and to provide a strong, hard durable filling. After years of research, mercury has been found to be the only element that will bind these metals together in such a way that can be easily manipulated into a tooth cavity.

Is mercury in dental amalgam safe?

Mercury in dental amalgam is not poisonous. When mercury is combined with other materials in dental amalgam, its chemical nature changes, so it is essentially harmless. The amount released in the mouth under the pressure of chewing and grinding is extremely small and no cause for alarm. In fact, it is less than what patients are exposed to in food, air, and water.

Ongoing scientific studies conducted over the past 100 years continue to prove that amalgam is not harmful. Claims of diseases caused by mercury in amalgam are anecdotal, as are claims of miraculous cures achieved by removing amalgam. These claims have not been proven scientifically.

Why do dentists use dental amalgams?

Dental amalgam has withstood the test of time, which is why it is the material of choice. It has a 150-year proven track record and is still one of the safest, durable and least expensive materials to a fill a cavity. It is estimated that more than 1 billion amalgam restorations (fillings) are placed annually. Dentists use dental amalgams because it is easier to work with than other alternatives. Some patients prefer dental amalgam to other alternatives because of its safety, cost-effectiveness, and ability to be placed in the tooth cavity quickly.

Why don’t dentists use alternatives to amalgam?

Alternatives to amalgam, such as cast gold restorations, porcelain, and composite resins are more costly. Gold and porcelain restorations take longer to make and can require two appointments. Composite resins, or white fillings, are esthetically appealing, but require a longer time to place the restoration. It should also be known that these materials, with the exception of gold, are not as durable as amalgam.

What about patients allergic to mercury?

The incidence of allergy to mercury is less than one percent of the population. People suspected of having an allergy to mercury should receive tests by qualified physicians, and, when necessary, seek appropriate alternatives. Should patients have amalgams removed? No. To do so, without need, would result in unnecessary expense, and potential injury to teeth.

Are staff occupationally exposed?

Dentists are using pre-mixed capsules, which reduce the chance of mercury spills. And newer, more advanced dental amalgams contain smaller amounts of mercury than before.

An interesting factor can be brought into this: Because dental staff are exposed to mercury more often, one would expect dental personnel to have higher rates of neurological diseases, such as multiple sclerosis. They do not.

What are other sources of mercury?

Mercury can be found in air, food, and water. We are exposed to higher levels of mercury from these sources than from a mouthful of amalgam.


Study Finds No Link Between Amalgam and Decrease in Mental Abilities

CHICAGO– Research published in the Journal of the American Dental Association (JADA) indicates amalgam fillings are not associated with lower mental performance, a precursor to age-related neurologic diseases including Alzheimer’s disease.

Dental amalgam, often referred to as silver filling, is a safe, durable and cost-effective material that dentists have used in tooth restorations for more than 150 years. It is composed of silver, copper and tin, with mercury chemically binding the other components into a hard, stable and safe restorative material.

The study tested the cognitive functions of a group of 129 Roman Catholic nuns between the ages of 75 and 102 for memory, language, the ability to judge distances, concentration and orientation. The research found that the number and amount of existing amalgams did not produce a lowering of cognitive functions.

“This study was conducted as a part of a larger study on aging and Alzheimer’s disease,” said J. Rodway Mackert, Jr., DMD, Ph.D., of the Medical College of Georgia, Augusta, Ga. and spokesperson for the American Dental Association. “It is significant because it is the first assessment of the effect of patients’ amalgam fillings on their cognitive function. The authors found no impairment of cognitive function on any of the tests as a result of dental amalgam fillings. The results of this study are further evidence of the safety of dental amalgam as a filling material.”

“In fact,” he continued, “the study found that the group of sisters with the highest amount of amalgam surface area in their teeth had the same mean test scores as the group of sisters that had dentures, and therefore no amalgams.”

The study focused on 129 nuns living in a retirement and health care facility in Elm Grove, Wis. The setting was ideal for the study because of a lack of confounding factors due to their similar lifestyles, including moderate use of alcohol, no tobacco use, similar housing, meals prepared from similar kitchens, and similar access to health care and other social supports.

Source: ADA News Release, Nov. 1995

American Dental Association Recommendations
Based on current evidence, ADA offers the following recommendations for dentists:

  • Continue to use amalgam as the material of choice if esthetic results are not of overriding concern;
  • Prepare the tooth as conservatively as possible, making access large enough only for removal of carious dentin and using resin sealants for noncarious fissures;
  • Use amalgam bonding systems, but continue to monitor research reports for the long-term effectiveness of such systems;
  • When clinical research demonstrates that tooth-colored restorative materials are as economical and effective in the long term as dental amalgam, switch to the more esthetically pleasing materials.


Position of the British Dental Association

This Fact file summarizes current thinking on the use of dental amalgam. To date, extensive research has failed to establish any links between amalgam use and general ill health. Those countries which are limiting the use of amalgam are doing so to lower environmental mercury levels. Most dentists are continuing to use amalgam for cavities where a very durable material is needed _especially in the chewing surfaces of posterior teeth.

What is amalgam?

A dental amalgam is produced by reacting the liquid metal, mercury, with metal alloys. Conventional silver-tin amalgam usually also contains small amounts of copper and zinc. High copper amalgams are prepared from either a mixture of silver-tin and silver-copper alloys or from a silver-copper-tin alloy. High copper amalgams have better clinical properties with a higher resistance to corrosion and marginal breakdown.

In many respects amalgam is an ideal filling material. As well as being very durable, it expands and contracts with temperature change at the same rate as the surrounding natural tooth. At their current level of development, and except for more expensive gold restorations, alternatives to amalgam do not performs so well in parts of the teeth which are subject to a lot of wear. Filling materials need to last as long as possible because replacement weakens the remaining natural tooth and may make more complex treatment necessary. Dental health is improving, however, so the number of amalgam fillings being inserted in the UK is falling.

Can mercury from amalgam fillings reach the rest of the body?

Like most bio-materials, dental amalgam is not inert. Amalgam fillings release mercury vapor, especially when teeth are chewed on or brushed. Some of the vapor is exhaled but some reaches the rest of the body through inhalation. Some also dissolves in saliva and is swallowed. The amount of mercury which reaches the rest of the body is very small and its relationship to the number of teeth with amalgam fillings is unclear.

Much of the mercury entering the body is excreted but some accumulates in certain organs – especially the kidneys but also in the brain, lungs, liver and gastrointestinal tract.

However, experts do not believe that the levels of mercury exposure resulting from amalgam fillings are of any general health significance. In 1986 the Department of Health’s Committee on Toxicity reviewed the evidence and concluded: “In our opinion the use of dental amalgam is free from risk of systemic toxicity and only a very few cases of hypersensitivity occur.”

Since 1986, more has been learned about the rate of release of mercury from fillings and about its destination in the body but extensive research has still failed to establish any links between amalgam use and general ill health. The Department of Health stands by the 1986 conclusion of the Committee of Toxicity, telling the BDA in November 1995: “The subsequent research findings and recent evaluations by several authoritative national and international expert committees are consistent with that advice.”

Do dentists say that amalgam is safe?

Whether amalgam can be called ‘safe’ is a matter for manufacturers of amalgam and for the Department of Health, and for the toxicologists and other scientists who advise them. Dentists comment on the dental properties of the material. If amalgam was found to harm general health dentists would stop using the material immediately. Dentists and their staff are concerned about their own safety too and research into their health can give insights into the likely safety of amalgam for patients.

It is never possible to say categorically that anything is safe in all circumstances. With amalgam, as with all bio-materials, there are risks and benefits to be balanced. Until all dental decay can be prevented, decayed teeth either have to be filled or, ultimately, extracted. Loss of natural teeth impairs eating, speaking and socializing. Also, use of an alternative to amalgam may raise the possibility of other complications and if the alternative is less durable it will fail more quickly and need to be replaced more often.

All dentists can do is keep abreast of the research and be prepared to change prescribing practices if new evidence emerges. However, it is worth pointing out that the establishment of a link between amalgam use and a condition such as dementia in elderly people is, in principle, a feasible subject for research if long-term dental records are available and the study population is large enough. An important long-term study of ageing is currently taking place in an American convent. Initial findings show no link between mental cognitive performance and numbers of amalgam fillings1.

But mercury is toxic, isn’t it?

Mercury is certainly toxic at large enough doses but the research does not indicate that the small exposures which result from the use of dental amalgam are harmful. Many substances are toxic at certain dose levels and for certain people, depending on individual susceptibility. Some people are even allergic to ingredients in foods such as bread and milk. About 3% of the population are estimated to suffer from mercury sensitivity2. Reactions sometimes occur in the soft tissues of the mouth next to fillings, not only with amalgam but with other restorative materials too. Amalgam is not especially allergenic and true sensitivity reactions are very rare. They may resolve spontaneously or after a change of restorative material. Suspected allergies are investigated by dermatologists/allergists and by oral medicine departments of dental hospitals, on referral from the dentist.

Who regulates dental filling materials?

The Department of Health’s National Health Service approval systems are now giving way to European regulation. Currently, manufacturers of dental amalgam can volunteer their products for CE marking, which demonstrates compliance with the Essential Requirements of the Medical Devices Directives. From June 1998 it will be a requirement that they do this, if products are to be used within the European Economic Area (EEA). The system requires an assessment of toxicological risks, with identification of all hazards being the first stage of this process.

In the end, no product can be proved safe, and new hazards can always be discovered. The courts ultimately decide the issue, rather than scientists. For example, breast implants were the subject of successful litigation, even though they had achieved wide acceptance following extensive use prior to the introduction of regulatory controls.

How much of our day-to-day mercury intake comes from dental fillings and how much comes from other sources?

Exposure to mercury depends on diet, any occupational exposure, and environmental mercury levels, as well as on amalgam fillings. On average, a UK adult absorbs about 9 millionths of a gram of mercury a day from all sources. About a sixth of this amount comes from amalgam fillings. Certain foods have high mercury content – fish, for example. Baseline mercury levels in Icelanders are about ten times higher than in the UK population because of the amount of fish eaten there.

How can patients find out about mercury exposure?

The mercury content of urine, hair, blood, breath or finger nails can be measured and dentists and their staff can monitor their own exposure by sending specimens for laboratory testing. Patients concerned about exposure to mercury could ask dentists to arrange testing in the same way but the test could not be provided under National Health Service dental arrangements. Also, the test would not necessarily identify the source of any mercury identified. Is it possible to remove mercury absorbed into the body?

Patients with severe mercury poisoning are sometimes prescribed ‘chelating agents’ which combine with mercury to produce a substance which can be more readily excreted. However, there is no evidence that removal of mercury through chelation has any beneficial effect for patients with symptoms believed to be caused by low exposure from amalgam fillings.

Chelation has side effects of its own. How should amalgam fillings be removed?

While there is no proof of a toxic effect during removal of amalgam fillings, there are the risks associated with the removal of any filling material_namely, inhalation of particles. With amalgam removal, there is also a potential hazard from inhaled mercury vapor. Risks can be minimized with copious use of water and adequate suction. The turbine spray can be supplemented with a 3-in-1 syringe plus suction with a high volume wide bore tube. A rubber dam may also be used. Removal by piecemeal sectioning also helps to minimize risks.

Because the risk during amalgam removal is concerned mainly with particle inhalation, there is not an additional risk in removal of many amalgams at one session. However, subsequent restoration may be made more difficult because of occlusal contact problems, so removal of amalgams may take place over several visits.

Vitamin C is sometimes given in high doses for patients having amalgam fillings removed but there is no evidence that this has any benefit.

Should amalgam be used during pregnancy?

It is known that mercury can cross the placenta from mother to fetus and can also be detected in breastmilk but this does not mean that amalgam fillings should be avoided during pregnancy or breast feeding. There is no evidence of any link between amalgam use and birth defects or still births. Generally, it is sensible to minimize health interventions during pregnancy and breast feeding, where this is clinically feasible. Dentists would approach the placement or removal of amalgam fillings from the same precautionary standpoint.

Should amalgam be used for children?

Children who have a good diet and oral hygiene can usually be treated successfully using sealant resins and glass ionomer cements. But once a posterior cavity approaches one third of the occlusal width and once any mesial or distal extension is not bound by enamel glass ionomer fillings are not normally recommended and amalgam is an acceptable restorative material. Is there any group for whom amalgam should not be used?

Patients with proved amalgam sensitivity are the only group for whom the placement of new amalgam fillings is not advised.

Should amalgam fillings be kept below a safe maximum related to body weight?

Safety thresholds apply in many areas of health care and were considered for amalgam fillings last year by a report commissioned for the Canadian Government3. The concept is logical but the data available about rates of mercury release and about potential toxicity do not permit an amalgam filling safety threshold to be reliably identified. The Canadian Government has since said that current evidence does not indicate that dental amalgam is causing illness in the general population and no safety threshold has been approved.

What do other governments and health bodies say?

No government or reputable scientific medical or dental body anywhere in the world accepts, on present published evidence, that amalgam is a hazard to general health. The World Health Organization agrees that amalgam should continue in use. In America, the Public Health Service, the National Institute for Dental Research and the American Dental Association all support continued use. The Swedish Medical Research Council found no connection between health problems and amalgam use and the phasing out of amalgam in that country is for environmental reasons.

Should dentists explain current concerns about amalgam safety when suggesting its use?

Law and medical ethics require that patients are told enough about a proposed treatment and any associated material risks to enable them to reach an informed decision on whether to accept the treatment. The information given by the dentist will be a matter for personal judgement. In the case of a child with multiple allergies, the possibility of mercury or amalgam hypersensitivity might be raised, for example.

It is in the end for the courts to decide what is a reasonable level of information. However, based on recent legal decisions about the requirements for consent, and in the light of current scientific opinion and statements by the Department of Health, the BDA’s advice to dentists is that it is not necessary to discuss the alleged links between amalgam use and health problems with generally healthy patients. Until there is a reputable body of opinion which believes that there are material risks in amalgam use, consent given without discussion of side-effects can be regarded as `informed’. Dentists should, of course, be prepared to answer patients’ questions about the safety of dental amalgam.


  1. Saxe SR, Snowden NA, Wekstein MW, Henry RE, Grant FT, Donegan SJ and Werstein DR, Dental amalgam and cognitive function in older women. Findings from the nun study. Journal of the American Dental Association 1995; 126: 1495-1501
  2. Mackert JR, Dental amalgam and mercury, Journal of the American Dental Association 1991; 122 (9): 54
  3. Richardson GM, Assessment of mercury exposure and risks from dental amalgam, Report to Canada Health © British Dental Association, 64 Wimpole Street, London, W1M 8AL

Source: British Dental Association. 

Dental amalgam is a mixture of various metals, but is primarily composed of mercury, silver, copper and tin. Used in dentistry for more than 150 years, this material offers a number of important advantages. For example, it is inexpensive, highly durable, and easy to place. A decayed tooth can be treated in a single visit to the dentist in most cases.

A possible disadvantage of dental amalgam is its silver color. Some Canadians want their teeth to look completely natural. If this is a concern to you, talk to your dentist about alternative restorative materials.

Dental amalgam restorations release minute amounts of mercury vapor, especially with chewing. Some of this mercury may be absorbed by the body, reach various organs and, in pregnant women, cross the placenta.

The body also absorbs mercury from other sources, including air, water, soil and food.

For the vast majority of Canadians, the small amount of mercury released by dental amalgam is not a cause for concern. Despite more than 150 years of observation and investigation, scientists have found no sustainable evidence that dental amalgam causes illness.

Health Canada, which is the government body responsible for regulating the sale of medical devices and materials in Canada, considers dental amalgam to be a safe, efficacious dental material for the vast majority of Canadians. This scientific assessment is shared by most medical and dental researchers around the world.

A small number of people are allergic to dental amalgam, in much the same way that individuals are allergic to dairy products or bread. If you are concerned about allergies, talk to your dentist.

Your dentist may also suggest an alternative material, or possibly delaying treatment, if you are pregnant.

Canadians who suffer from immune system conditions, a neurological condition, or have impaired kidney function, may also wish to discuss alternative materials with their dentist. Although these conditions are not linked to dental amalgam in any way, mercury absorption may be of particular concern to these individuals. A position statement on dental amalgam, which was released by the Health Protection Branch of Health Canada in August 1996, recommends that, “whenever possible, amalgam fillings should not be placed in or removed from the teeth of pregnant women.”

This statement also recommends that “non-mercury filling materials should be considered for restoring the primary teeth of children where the mechanical properties of the material are suitable,” and that “new amalgam fillings should not be placed in contact with existing metal devices in the mouth, such as braces.”

In a subsequent information sheet, Health Canada recognized that “although it is preferable to avoid dissimilar metals in the mouth, there may be situations where there is no practical alternative.” The sheet also notes that the galvanic effects that may occur when dissimilar metals are used in proximity to one another are usually not severe enough to justify the removal of dental amalgam restorations, if it is necessary to place other metal restorations or devices, such as gold crowns, braces, or metal wires, in your mouth.

Dentists also consider a number of factors when they develop treatment plans for children and pregnant women. In many cases, dental amalgam is still the best treatment option available, depending on the location and extent of decay.


Health Canada Position Statement on Dental Amalgam

Health Canada advises dentists to take the following measures:

  1. Non-mercury filling materials should be considered for restoring the primary teeth of children where the mechanical properties of the material are suitable.
  2. Whenever possible, amalgam fillings should not be placed in or removed from the teeth of pregnant women.
  3. Amalgam should not be placed in patients with impaired kidney function.
  4. In placing and removing amalgam fillings, dentists should use techniques and equipment to minimize the exposure of the patient and the dentist to mercury vapor, and to prevent amalgam waste from being flushed into municipal sewage systems.
  5. Dentists should advise individuals who may have allergic hypersensitivity to mercury to avoid the use of amalgam. In patients who have developed hypersensitivity to amalgam, existing amalgam restorations should be replaced with another material where this is recommended by a physician.
  6. New amalgam fillings should not be placed in contact with existing metal devices in the mouth such as braces.
  7. Dentists should provide their patients with sufficient information to make an informed choice regarding the material used to fill their teeth, including information on the risks and benefits of the material and suitable alternatives.
  8. Dentists should acknowledge the patient’s right to decline treatment with any dental material.

Source: Canadian Dental Association


Can a Dentist Ethically Remove Serviceable Amalgam (Silver) Fillings?

CHICAGO –Can a dentist ethically remove serviceable amalgam fillings? That question is posed in the May 1996 issue of the Journal of the American Dental Association (JADA).

The JADA article, authored by ADA general legal counsel Peter Sfikas, asks the question as stories surface regarding the safety of dental amalgam (silver fillings). Interest in the topic of whether removing serviceable amalgams has any health benefits heightened recently with the case of Colorado dentist Hal Huggins, a proponent of the theory that dental amalgam is a source of mercury toxicity. The Colorado Board of Dentistry recently revoked Dr. Huggins’s dental license.

“The scientific community agrees that amalgam is a safe and durable tooth filling material,” Mr. Sfikas said. “The ADA’s ethics policy clearly states that `no dentist shall remove an otherwise serviceable amalgam filling for the sole purpose of curing a systemic disorder,'” he added. The ADA believes that when such treatment is performed only on the recommendation or suggestion of the dentist, it is unethical and improper, since removal of dental amalgam has not been shown to have any beneficial effect on the general health of the patients or their specific medical conditions.

“What’s unfortunate is that patients with serious, incurable diseases are the most vulnerable to these reports of supposed miracle cures, like the removal of serviceable amalgams,” Sfikas commented. “There is absolutely no scientific proof that removing amalgams for the alleged purpose of eliminating toxic substances from the body is beneficial, unless, of course, the person is allergic to the mercury.”

What should a dentist do if a patient asks the dentist to remove patient’s serviceable amalgams? Mr. Sfikas provides the following guidelines:

  1. A dentist is not ethically obligated to remove serviceable dental amalgams from the non-allergic patient at the patient’s request or even the recommendation of the patient’s physician.
  2. The dentist has the professional obligation to use his or her independent judgment about the dental treatment that is best for the patient.
  3. The dentist is free to suggest that the patient seek dental care elsewhere.
  4. If a dentist agrees to remove serviceable amalgam restorations from the non-allergic patient at the patient’s request:
  5. The dentist should take special care to obtain the patient’s informed consent to the procedure and thoroughly document that consent in the patient’s records.
  6. The dentist should review with the patient the current scientific thinking on the safety of dental amalgams –that there is no evidence that amalgams pose a significant health risk to non-allergic patients and that no known health benefits result from removal of dental amalgams.
  7. The patient should be informed of the risks involved in replacing amalgam restorations, including potential damage to healthy tooth structure and the loss of sound tissue in the process.
  8. The patient should also be informed of the risks and benefits of the replacement materials and the cost.

Finally, the dentist should clearly state that he or she promises no health benefits to the patient by removing serviceable amalgam restorations.

Mr. Sfikas answers the question posed in the article’s title by saying that serviceable amalgams can ethically be removed by a dentist but only under very limited circumstances and only if the patient provides informed consent to the procedure.

Source: ADA New Release, May 1996.


Dental Amalgam–Patient Teaching

Do amalgam fillings contain mercury? Yes.
Does mercury escape from amalgam fillings? Yes.
Have the levels of mercury released by amalgam fillings been shown through controlled scientific study to be dangerous? No.

Clearly, we need to be sensible about the information we provide to the public. Anecdotal information and simple facts quoted out of context without qualification and without correct interpretation can be misleading and alarming.
Mercury is a component of the amalgam used in silver-colored fillings. The other major ingredients are silver, tin, copper, and zinc. When mixed, these elements bond to form a strong, stable substance. The average content of mercury in an amalgam restoration is slightly less than 50 percent.
For more than 150 years, billions of amalgam restorations have been placed and a National Institutes of Health report states that only 50 documented cases of allergy to mercury have been reported in scientific literature since 1906. One hundred million people in the United States have amalgam fillings and 100 million amalgam fillings are placed each year.
Studies show that no filling material has been proven superior to amalgam in safety, durability, and cost effectiveness. Amalgam has been researched worldwide and no study has ever caused a professional dental organization or agency to recommend a ban of amalgam.
The amount of mercury ingested by someone with amalgam restorations is minuscule – well below established health safety standards. Mercury also enters the body through the ingestion of food (i.e., fish) and water, and through breathing air. Eventually, the body rids itself of mercury, but there is always a very low level of mercury present in the body.
In 1995, following a meeting of government health officials from nine European nations, the United States and Canada, the U.S. Public Health Service released a statement reiterating that there are “no scientifically compelling reasons either to discontinue or to curtail the clinical use of dental amalgam or to recommend removal of existing amalgam fillings,” without clear evidence of allergy or intolerance in individual patients.
A 1999 article in the Journal of the American Dental Association, reported that researchers found “no significant association of Alzheimer’s disease with the number, surface area or history of having dental amalgam restorations.” Other claims that the removal of amalgam fillings leads to recovery from multiple sclerosis or that the use of amalgam leads to arthritis are unsubstantiated and without scientifically established cause and effect.
The CDA does not believe that a dentist should prey upon the fears of people who have serious medical conditions by selling them dental treatment that may cost thousands of dollars and for which no cure has been proven.
In 1997, the World Health Organization stated that no controlled studies have been published demonstrating systemic adverse effects from amalgam restorations.
The long-term cost of two- or three-surface gold or composite restorations in permanent teeth is about four times greater than for amalgam restorations.
There is no sound scientific evidence to support any health benefits from the removal of amalgam. The ADA Council on Ethics, Bylaws and Judicial Affairs has stated that “Based on available scientific data, the ADA has determined…that the removal of amalgam restorations from the non-allergic patient for the alleged purpose of removing toxic substances from the body, when such treatment is performed solely at the recommendation or suggestion of the dentist, is improper and unethical.” Replacing dental amalgam for aesthetic purposes has its own risks and the dentist should discuss all of the risk/benefits with the patient before replacing serviceable amalgam restorations.
The Dental Board of California has prepared a Dental Materials Fact Sheet that describes the various restorative materials available to the dental profession for restoration of an oral condition or defect. The relative benefits and detriments of each group of materials are also provided. This information is being provided by an independent, qualified scientific consultant and is available to all licensed dentists in California to make available to their patients.

Source: California Dental Association, June 2001.