Contents Post-Test

THE EXTENDED DENTURE

The purpose of this course is to give a practical way of making fully extended maxillary and mandibular dentures that will hold in place without the benefit of adhesives. I have developed this technique over the last forty years.

The mandibular extended denture takes advantage of the divergent angle of the mandible. Distal to the mylohyoid line, the angle of the mandible diverges outward. By extending the denture into this area, the denture will incorporate an undercut.

The mandibular denture is brought forward into the undercut and slipped over the anterior alveolar bone. The mandibular denture is held in place by the amount of undercut and the lingual seal created by the tongue at the plica sublingualis. If the patient can tolerate this mandibular extension of the denture, the denture will be locked into place.

When the tongue lies on the lingual side of the anterior mandibular denture, it creates a seal similar to the post dam of the maxillary denture. How far the anterior lingual side of the mandibular denture can extend toward the plica sublingualis is determined by the muscles in the floor of the mouth. The more surfaces the tongue has to cover, the better the seal; however, the plica sublingualis should not be covered.

The undercut and the anterior lingual extensions of the mandibular denture are adjusted to accommodate the patient. Both areas will need to be shortened until the patient can tolerate the extension. This will vary with each patient. Before the shortened process becomes too aggressive, the patient should be given the opportunity to adjust to the extended denture. Most patients can tolerate at least a certain amount of the undercut and anterior lingual seal.

The maxillary-extended denture extends as high up on the tuberosity of the maxilla as the tissue will allow going from one side of the maxilla to the other side. The hard palate is completely covered with the beaded post dam, sealing the posterior portion of the denture in the tissue of the soft palate.

The seal of the denture depends on the beaded post dam and the amount of extension the patient can tolerate over the tuberosity of the maxilla. The goal in the construction of the maxillary denture is to create a suction that will hold the maxillary denture in place. Therefore, the maxillary denture is extended into the vestibule as far as the tissue will allow.

Anecdote

A patient came into my office requesting full maxillary and mandibular dentures. I removed the maxillary denture, but the mandibular denture would not move. I assumed the patient had used adhesives and started to pry the denture loose when it suddenly was released.

The examination revealed the patient had no lower mandibular ridge. The floor of the mouth was flush with the alveolar ridge. A small rib of tissue marked the location of the alveolar bone on the mandibular.

The patient had held the mandibular denture in place by creating suction. He had an extended denture that was constructed to cover a wide portion of the alveolar bone and the surrounding tissue to provide a surface for the suction. He did this by placing his tongue on the lingual side of the anterior portion of the denture, sealing it. He had learned how to hold his tongue in this area while he ate and talked. I could not remove the denture until he released the seal.

The Extended Denture is Made in Five Appointments:

First Appointment: The initial impression is taken to make the trays.

Second Appointment: The final impression is taken with preformed acrylic trays.

Third Appointment: The vertical dimension is established and the teeth are selected.

Fourth Appointment: The wax up with the teeth in place is tried in the mouth.

Fifth Appointment: The full denture is inserted.

Denture adjustments are done as needed until the denture is comfortable in the patientís mouth.

ORAL EXAMINATION

This is an opportunity to evaluate the patient and his denture. A thorough examination of the mouth is taken.

  1. The amount of alveolar bone on the ridges is evaluated.

    1. The more alveolar bone, the better the denture will fit.

    2. High tissue attachments will unseat the denture easily.

  2. The thickness of the alveolar mandibular ridge is normally an inch-and-a-quarter to an inch-and-a-half. If the ridge is down to a half-inch or less, you can expect the mental nerve to be on the ridge or very close to the ridge.

  3. The mandibular ridge is checked for lingual and buccal tori. These may need to be removed before the denture is constructed because the tissue over the tori is very thin, and it can be cut very easily with a hard denture. This injury can become very painful and take several weeks to heal.

  4. The third molar region on the mandibular ridge may show a sharp bony ridge on the lingual side from bone resorption. This may need to be smoothed before the denture is constructed.

  5. The palatal tori on the maxillary palate need to be evaluated. If the tori are smooth and do not go into the post dam area, they may not need to be removed.

  6. Occasionally, the maxillary alveolar bone has buccal tori in the molar areas. Usually these need to be removed if they present sharp edges and deep undercuts.

  7. If the palate exhibits a rise in bone other then in the midline of the palate, a neoplasm should be suspected.

  8. If papillary hyperplasia is present, it must be treated before the denture can be made. This is a condition brought on by the wearing of a loose-fitting maxillary denture. The condition will clear up with the removal of the old denture for two to three weeks. It can be surgically removed, but this is not the treatment of choice.

  9. The submandibular and parotid glands needs to be finger probed to ensure they are not swelled.

  10. The patientís current denture needs to be examined.

    1. Flat, worn teeth will indicate the patient is a grinder. You cannot give a patient with worn teeth replacement teeth with a steep anatomy.

    2. Multiple fractures in the acrylic would indicate the patient clenches. A thin denture will not work for this patient.

    3. A denture full of debris indicates the patient will not take care of his new denture unless he can be taught the proper care for it.

    4. Denture adhesives in the denture will indicate the patient has been experiencing bone loss. The age of the denture will tell you how severe this is. Usually a narrow mandibular denture will cause the bone to reabsorb at a faster pace then a full, extended denture.

    5. Is the patientís musculature distorting when he closes on his present denture? This would indicate the vertical is off and the denture is over closing.

  11. If the patient is going to have an immediate denture, the teeth to be extracted need to be evaluated. If the teeth are mobile and present no problems in the extraction phase, the denture can proceed. If one or two teeth are going to be extremely difficult, it is wise to extract these teeth before the denture is started.

A badly decayed maxillary cusp usually requires a tissue flap before it can be removed. This is not something you would want to leave under a denture. It is better to wait until the tissue is healed and the sutures are removed.

THE EXTENDED DENTURE:
FIRST APPOINTMENT:

The initial impression is taken to make the trays.

Materials needed:
  1. Alginate impression material.
  2. Maxillary and mandibular trays
  3. Green rubber mixing bowl and spatula

An alginate impression is taken of the maxillary and mandibular arches. The mandibular impression is taken first to allow the patient to become used to the material you are using. The patient lifts his tongue to allow the impression tray to slip below it. This should be practiced first without the alginate impression material in order to correct any problems the patient may experience.

If the patient has existing teeth (immediate dentures), the wet alginate impression material is scooped up with a finger and spread over the labial side of the mandibular anterior teeth. This is important to ensure the lower lip will not remove the alginate. This becomes especially important for patients with tight lower lips.

The maxillary impression is taken with the patient sitting almost all the way forward. He is instructed to breathe through his nose. Most of the gagging problems can be attributed to the patient trying to breathe through his mouth, which creates an air hole when the impression material is placed. The impression material slips down the air hole, causing the patient to gag.

The patient becomes anxious when he cannot breathe through his mouth and the loose impression material has moved down his throat. The patient is instructed to hold his breath, think of his nose, and then breathe through his nose. You may need to talk him through the process. The patient can breathe anytime he chooses through his nose while the impression material is in his mouth.

On extremely rare occasions, when the patient is going to regurgitate the impression material before it is completely cured, you might try to pull the offending piece of material from the patientís throat with a finger sweep.

No matter how much material enters a patientís mouth, he will tolerate it as long as it is not loose. If the patient feels something loose, he will attempt to swallow it so that he can breathe, bringing on the gagging reflex.

When the impressions are completed, they are wrapped in a wet paper towel, placed in a plastic zip-lock bag and sent to the laboratory. At this stage, it is good to do the lab work in the office for a quick turn around time.

LABORATORY:
The Acrylic Tray:
Materials:
  1. Coe Tray Plastic
  2. Porcelain Jar
  3. Spatula
  4. Scissors
  5. #2 round bur and hand piece.
  6. Emery Cloth Arbor Band and Chuck
  7. Balder Polishing Lathe
  8. Large acrylic round bur

The impressions are poured with wet plaster stone and placed on wet plaster stone bases. The bases are trimmed while the plaster stone is wet with the spatula. This will reduce or eliminate the need for model trimming later.

While the plaster stone is wet, the lingual extensions on the mandibular model are created by scraping a groove in the plaster stone deeper then the impression. The idea is to allow the tray to extend toward the angle of the mandible. The rough areas are smoothed and the plaster stone is allowed to dry.

The impression material is removed, leaving the plaster stone models. The rough edges are removed and the plaster stone models are placed under water to saturate the stone. A pencil is used to draw the periphery of the trays to be made on the stone models. The maxillary post dam should be identified and marked with the pencil.

Coe Tray Plastic is used to make the trays. One full measure of the powder is placed in a porcelain jar, and the liquid is added until the mixture is smooth and wet.

The Coe mixture will change from a creamy mixture to a doughy mixture. Make sure your hands are wet before touching the doughy mixture. If the mixture sticks to your fingers, you need to wait longer. When the mixture can be manipulated without sticking to your fingers, the doughy mixture is taken from the jar and split in half. Your hands must remain wet to keep the mixture from sticking to your fingers.

Maxillary Tray:

One-half of the doughy mixture is placed on a flat, wet surface. A small piece of the doughy mixture is snapped off for the handle, and the rest is flattened and shaped to fit over the wet maxillary stone model.

The doughy mixture is pulled from the stone model, and the excess material is cut off with a pair of scissors. The doughy mixture is placed back on the model and pressed to place. The idea is to keep a uniform thickness throughout the tray and to extend the tray into the periphery and post dam of the maxillary mold.

The small piece pinched off earlier is added to the maxillary anterior ridge for the handle, and then it is smoothed into the tray. It is important to keep the handle high on the ridge. The periphery of the tray needs to remain thin to allow space for the compound material to be added later.

Mandibular Tray:

The other half of the doughy mixture is placed on a flat wet surface, flattened and shaped to fit the wet mandibular plaster stone model. A small piece of the doughy mixture is snapped off for the handle.

The doughy mixture is pushed into the lingual groove created earlier to extend the tray. The handle is placed on the mandibular anterior ridge and smoothed into the tray portion of the doughy mixture. The periphery of the tray needs to remain thin to allow the compound to adhere later.

The doughy tray is pulled from the plaster stone model and trimmed with a pair of scissors. The doughy tray will distort in the process. This is corrected by placing the doughy tray back on the model and pushing the doughy tray to place.

If you are doing an immediate, the stone teeth need to be covered with a wet piece of paper towel to remove the undercuts before the doughy material is applied to the model.

Once the trays are hard, they are removed and trimmed with the emery cloth arbor band. The periphery needs to remain thin to allow room for the compound. The maxillary tray is trimmed back to the post dam marked on the stone model.

Using a #2 round bur, holes are punched through the plastic trays. The holes are spaced three millimeters apart and should cover the entire tray. This will allow the impression material to flow through the holes and lock to the tray.

A large acrylic round bur is used to remove any undercuts, allowing the tray to seat easily. The tooth impressions in the tray for the immediate dentures need to be burred well to remove the undercuts.

Possible Problems and their Solutions:
  1. The hands need to be wet through the whole process to keep the doughy mixture from sticking to your fingers.

  2. The doughty tray has a tendency to shrink and distort when it starts to cure. The material has to be constantly worked until the tray becomes hard.

  3. Two separate mixtures can be made for the maxillary and mandibular trays to allow more time to work the material.

  4. The handle for the trays can be formed by pulling up a portion of the tray material instead of pinching off a piece and adding it later. This will make the handle stronger and speed up the process.

Handle:

If you wish to make the handle separately, it can be added to the hard acrylic. A portion of the soft material is poured onto the surface where the handle will be placed. The handle is rolled, shaped and placed in the soft material on the tray. The handle is shaped and allowed to dry.

The handle does not need to be extended straight out. In fact, the handle usually works better slanting downward from the maxillary ridge or extending more upward and outward from the mandibular ridge. The handle needs to be fairly large. It will be your main point of thrust to remove the impression from the mouth.

SECOND APPOINTMENT:

The final impression is taken with the preformed trays.

Materials Needed:
  1. The newly constructed maxillary and mandibular trays
  2. Hot water (the coffee maker is convenient)
  3. Pan and cloth dipper to soften the compound in
  4. A package of red stick compound
  5. Hold Spray-on Tray Adhesive (Teledyne water pik)
  6. Alginate
  7. Bunsen burner
  8. Teledyne Water Pik - Hold Spray-on Tray Adhesive

The goal of the second appointment is to take a very detailed impression of the maxillary and mandibular alveolar surfaces and their extensions.

The trays are tried in the mouth and trimmed to fit. For immediate dentures, the trays occasionally may need more acrylic removed where the teeth are located. There should be enough room for the alginate to flow around the teeth. A slight hole in the tray can be tolerated, but an undercut will interfere with the impression.

Maxillary Denture Tray Impression:
Maxillary Tray:

The water is heated and poured into the pan with the cloth dipper. A stick of red compound is placed on the cloth dipper and lowered into the hot water for a few seconds. The cloth dipper carrying the red compound stick is removed from the hot water and placed across the pan. The hot water remaining in the cloth will continue to heat the compound.

When the red stick is pliable, it is lifted from the cloth dipper and applied to the acrylic tray. Starting at the anterior frenum, the compound is shaped over the edge of the acrylic tray and carried to the post dam area with moist gloved fingers.

The red compound on the tray is placed above the Bunsen burner and heated until the compound has a glaze. This will take only a second or two. Then the compound is blended in the acrylic tray with your wet, gloved fingers.

Another section is heated over the Bunsen burner. This is not an attempt to melt the compound. You are trying to make the compound more pliable. The compound is passed over the flame slightly to accomplish this. The wet fingers work the compound over the periphery of the acrylic tray. When the compound is secured to the acrylic tray, it is placed in the hot water for a few seconds to make the compound uniformly hot and to cool the hot spots from the flame. The compound should be touched with the back of your finger to insure the compound is not too hot to place in the patientís mouth.

The tray is placed in the patientís mouth, and the warm compound is pushed up into the vestibules. The cheek is pulled down across the compound to impress the contours of the attached tissue into the soft compound.

The tray is removed and inspected. The areas of overflow are heated briefly in the Bunsen burner flame and smoothed over. The tray is placed in the hot water for a few seconds and reinserted into the patientís mouth to contour the compound. Then the tray is removed and inspected. The compound should conform to the attached tissue. Always check the compound with the back of your finger before you place it in the patientís mouth.

In areas where the compound is short, more needs to be added. The end of the stick of compound is placed over the Bunsen burner flame. When it starts to melt, it is dripped over the compound on the tray where it is short.

When enough compound is added, it is shaped with a moist gloved finger. The tray is placed in the hot water bath a few seconds to cool the compound. Then the tray is placed in the mouth, and the cheek is stretched over the compound to contour it to the attached tissue.

The area of most concern is the posterior maxillary tuberosity as it flows into the post dam area. A good extension into this area will help to create a seal for the maxillary denture. If the compound is still short, more can be added until the compound has a good impression of the area.

The other side is done in a similar matter. If the compound is difficult to handle as one piece, it can be split in half. The first piece of compound starts at the frenum and works its way back toward the post dam. The second piece is added to the first piece and continues toward the post dam.

A piece of the red compound is heated and added to the post dam. The compound on the post dam is passed over the Bunsen burner flame until the compound has a glaze. The soft compound is shaped and pressed onto the tray with moist gloved fingers.

The compound is passed over the flame a second time to soften it more. Before the tray is placed in the mouth, it goes into the hot bath of water to cool the compound and give it a uniform temperature.

The temperature of the compound is checked once again with the back of your finger. When it will not burn the patient, the compound tray is placed in the mouth, and the post dam is pressed to the palate with moist gloved fingers. This will give a good impression of the post dam and ensure a tight fit.

The tray is sprayed with Spray-on Tray Adhesive and dried with the air syringe. It is now ready for the impression.

Maxillary Impression:

A small amount of alginate is mixed in the green bowl to a watery consistency. It needs to be thoroughly mixed. Then the thin mixture is poured into the acrylic tray. This impression does not require a large amount alginate. The tray already fits tightly to the palate. A thin layer of alginate is poured over the tray.

The patient is brought forward and reminded to breathe through his nose when the tray and impression material are placed. The excess alginate is removed, and the tray is inserted into the patientís mouth. The tray is pressed tight to the palate, starting from the post dam and going forward to move as much of the alginate to the anterior.

The alginate will flow through the bur holes in the acrylic tray to lock the impression in place. The excess alginate will flow into the patientís mouth, but if the patient is breathing through his nose, he will be able to tolerate the alginate in his mouth.

The alginate hardens and is removed from the patientís mouth by applying pressure on the handle. The impression should pop loose. The excess post dam alginate is cut free of the impression with a pair of scissors. The trimmed impression is wrapped in a wet paper towel and placed in a zip-lock bag.

Mandibular Tray Impression:
Mandibular Tray:

Compound is added to the mandibular tray in like manner as the maxillary tray, except the compound is carried into the lingual submandibular fossia (undercut). The right side is completely done before the left side is started. This will allow you to keep a point of reference when the tray is tried in the mouth with the compound.

The compound is heated in the hot water and applied to the buccal side of the tray. The compound starts at the mandibular frenum and works distally toward the triangular retromolar pad. The warm stick should be half the thickness of the cold stick.

Moist glove fingers work the warm compound onto the tray. The tray and compound are passed over the Bunsen burner flame. The compound glazes and adheres to the acrylic tray. Moist glove fingers can mold the compound before it is placed in the hot water to disperse the heat.

The compound is placed against the back of your finger. If the compound feels comfortable, the tray and compound are placed in the patientís mouth. Then the cheek and lips are pulled over the compound to make a mold of the attached tissue. After this, the tray is removed and examined, and compound is added or removed as needed.

The lingual portion of the tray is extended into the mandibular posterior undercut (angle) with the compound. The compound is heated in the hot water, and molded to the acrylic tray. It is glazed over the flame to seal the compound to the tray. The hot compound is cooled in the warm water and placed in the patientís mouth.

The gloved finger eases the compound over the mandibular ridge and retracts the tongue to allow the tray and compound to slip into the submandibular fossae (undercut). This extension should not incorporate the undercut. The impression will do this later.

More compound may need to be added to take the tray deeper into the submandibular fossae. The tray should extend along the floor of the mouth to the plica sublingualis. The mandibular lingual tray extension should be taken as low as the relaxed tissues will allow.

The tray should be extended on the buccal from the anterior frenum into the retromolar pad, and thence down into the lingual submandibular fossae. Once the right side of the tray can be inserted comfortably, the compound can be added to the buccal of the left side of the tray.

The same procedure is followed in extending the tray into the submandibular fossa. Care should be exercised when the flame is passed over the compound to avoid melting the compound on the right side.

The long extensions in the submandibular fossae need to be free of undercuts. The gloved finger will be needed to guide the soft compound into the fossae because the soft compound has a tendency to catch on the mandibular ridge and distort. Once the tray is in place, the gloved finger can push the compound back into position.

The tray should move in and out freely. The extensions on the lingual will appear as wings on the tray. The tray is sprayed with Spray-on Tray Adhesive and dried with the air syringe. It is now ready for the impression.

Mandibular Impression:

The alginate mix is very thin to allow easy flow of the material. The powder is well incorporated with the water until a smooth thin creamy mix is obtained. Then the compound tray is filled with the alginate impression material.

To keep the impression material on the compound tray you may have to movie it constantly. The patient raises his tongue and the tray is placed in his mouth and pressed into place. The impression material will flow out the bur holes and over the compound. The cheek, tongue, and lips are pulled free of the impression. The mental and anterior frenum attachments are worked through the impression material.

The fingers should be pulled free of the impression material when it starts to gel. Pressure needs to be continued, but you must use the handle. The impression is removed by lifting and pushing the tray distally.

The trayís impression material now has undercuts. To avoid distorting the impression, the tray is lifted slightly and pushed distally until the impression material is free of submandibular fossae. The tray is slowly removed from the patientís mouth, wrapped in a wet paper towel and placed in a zip-lock bag.

Possible Problems and their Solutions:
  1. It is very easy to over-flame the compound. You are only interested in a glaze. Also, you need to always go back to the warm water before placing the hot compound in the patientís mouth.

  2. When taking the maxillary impression, the post dam will extrude impression material. This needs to be carefully cut with scissors to avoid distorting the impression.

  3. The long, soft submandibular compound extensions on the mandibular tray tend to catch on the mandibular ridge and distort the material. This can be avoided by placing your finger on the ridge and guiding the soft extension into place.

  4. The alginate flows easily and gives a good impression, but it can also be very fragile. Other impression materials can also be used. Example: Kerr Extrude Wash.

  5. The compound sticks can be left in the hot water too long and distort into a flat blob. These can be redeemed by rolling the material back into a stick.

  6. Care needs to be exercised when placing more then one stick in the hot water. They may roll together and fuse.

  7. If the alginate is not thin enough on the compound tray when the impression is taken, the alginate will fill the tray and give a poor impression. The alginate needs to be paper thin across the tray and compound. The tray can always be scrapped clean of the alginate, and the impression can be retaken.

Laboratory:
Material Needed:
  1. Lab stone
  2. Green rubber bowl
  3. Spatula
  4. Four-by-four tile
  5. Lab knife

The maxillary and mandibular impressions are sent to the lab at this point. The impressions are poured and the bite blocks are made. Commercial laboratories can do this for you, unless you prefer to pour the models yourself.

We are taught in school to box the impressions and pour them. The commercial laboratories do not box the impressions. We will use the commercial process here.

Maxillary Pour:

The lab stone is mixed with water to a creamy consistency in order to incorporate all of the stone. The creamy mixture is removed from the bowl and placed inside three paper towels. The excess water is removed from the stone mixture by pressing the paper towels over the stone mixture.

Enough water is left in the mixture to allow the stone to flow easily into the impressions. Using the vibrator, the stone starts at the post dam and flows across the palate and into recesses. More stone is added until the stone protrudes above the impression.

Then a four-by-four inch tile is placed over the protruding stone. The tile and the stone-filled impression are turned over and placed on the bench.

The excess stone is pushed up around the impression with the spatula to cover the compound. The stone base should be at least a quarter of an inch thick.

When the stone begins to set, it is still very pliable. It should be shaped and trimmed from the impression using a spatula. The stone model needs to fit into the flask to process the denture. This should be kept in mind while you trim the stone from the impression. The stone is allowed to harden for several hours.

The cured stone model is placed in the hot water pan. The compound softens and the acrylic tray is removed. The model is lifted from the hot water and the soft compound is picked off the stone model.

Mandibular Pour:

The lab stone is mixed to a creamy texture, and the excess water is removed with paper towels. This technique removes the air bubbles incorporated in the stone while mixing. It leaves the stone pliable, and it gives it enough texture to hold its shape once it is poured into the impression.

The stone mixture is placed on one side of the impression and vibrated around the impression to the other side. To avoid injury to the impression, only the handle of the tray is vibrated.

Once the impression is covered, more stone can be added until it overflows. The impression filled with stone is covered with a four-by-four inch tile. The impression, stone and tile are turned over and placed on the bench. Then the spatula is used to pull the tray stone

material up around the impression. Attention needs to be paid to the lingual extensions to insure stone remains in the impression. Stone is added to the space between the extensions.

This impression is the most difficult one to pour because of the lingual extensions. There is a tendency to allow the extensions to push through the stone base. The peripheral compound border of the impression needs to be in the stone.

Once the stone begins to set, the spatula is used to trim the model. Repairs can still be made at this point. The excess stone is removed. The model needs to fit inside a flask later, which needs to be kept in mind during the trimming process.

The lingual extensions are worked free of the stone on the lingual side, and the stone is smoothed between the two sides. This will save you from digging the extensions out when the stone is hard. When the trimming and smoothing are completed, the stone is allowed to harden.

The cured stone model is placed in the hot water bath until the compound softens enough to remove the acrylic tray. The stone model is lifted out, and the remaining red compound is picked off. The stone model can be reinserted into the hot water to soften the compound more if necessary.

The stone models may need to be trimmed on the stone grinder to correct areas missed in the trimming. Usually a utility knife can make the minor corrections by smoothing over the sharp edges.

Possible Problems:
  1. The mandibular extensions may protrude out of the bottom of the base or be very thin in this area. More stone can be added to the base once the stone starts to set. The lab stone is mixed and drained of excess water with the paper towels. The tile and impres- sion full of stone is lifted off the bench. Taking the impression full of stone in your hand, turn them over. The tile is removed and more stone is added. The four-by-four tile is replaced. The impression full of stone and tile are turned back over and placed on the bench. Then the spatula is used to remove the excess stone and correct the voids.

  2. It is important to remove the stone on the lingual side of the extensions. Stone should be removed all the way to the bottom of the compound. This will save time digging them out later in hard stone.

  3. The size of the flask should be kept in mind during the trimming process. The base does not need to extend more then a quarter of an inch below the lingual extensions.

Bite Blocks:
  1. Pro-Form machine
  2. Preformed baseplate
  3. Baldor polishing lathe
  4. Emery cloth arbor band and chuck
  5. Baldor lathe
  6. Ridge form wax
  7. Large square spatula
  8. Utility knife
  9. #7 wax spatula

At this point, the models can be sent to the lab to make the bite blocks, unless you have a Pro-Form machine. The old method of using a Bunsen burner to heat the shellacked base is time consuming.

The stone models are trimmed, and all of the undercuts and sharp areas are removed. The study model is placed in water. This will prevent the hot baseplate from sticking to the stone.

The four-by-four preformed baseplate is placed in the pro-form machine and heated. The wet stone model is placed below the baseplate. When the baseplate begins to flow from the heat being applied, it will drop toward the study model in a bubble shape.

When the melting baseplate has dropped one inch towards the wet study model, the suction is turned on. The baseplate quickly forms over the study model. The study model and baseplate are cooled in running water.

The emery cloth band is placed on the Baldor lathe. Keeping the study model at a forty-five-degree angle, the emery cloth arbor band cuts through the baseplate to the stone, following the periphery of the stone impression. The cut encircles the study model.

The mandibular cut goes up over the retromolar pad. Care must be exercised to avoid cutting into the pad. A loose band of base material around the study model is left. The band is freed from the study model when the emery cloth arbor band cuts through it.

The remaining baseplate is eased off the study model with a utility knife and trimmed with a pair of curved stainless steel scissors and the emery cloth arbor band.The material between the posterior extensions is removed with the curved stainless steel scissors. Be careful because the material is usually very thin in this area and can tear.

Ridge-form wax is glazed over the Bunsen burner and placed on the baseplate following the stone ridge. The #7 wax spatula is heated and applied to the wax where it touches the baseplate. The wax will flow and seal the wax to the baseplate. The anterior wax is far enough forward to allow the flat spatula to touch the labial surface of the baseplate and the wax form. The hot large spatula is moved across the labial surfaces, causing the wax to flow and become smooth.

A wide strip of wax can be cut from a sheet of wax and applied to the labial surface of the wax bite block to cover any discrepancies in the bite block. The hot large spatula is used to shape the wax onto the labial side of the bite block, leaving a smooth surface.

Possible Problems:
  1. If the baseplate on the Pro-Form machine is allowed to bubble too far before the base- plate is lowered over the stone model, it may come out too thin. A thin baseplate will warp when the hot wax is applied and may split when pressure is applied.

  2. The thicker portions of the baseplate need to be ground off with the emery cloth band because scissors will fracture the thicker portions of the baseplate.

  3. The wax bite can be made without ridge-form wax by heating and rolling a sheet of wax. The wax is shaped and fitted to the baseplate with the large spatula. Additional wide strips of wax are added to remove discrepancies. The disadvantage to this method is that the excessive heat being applied to the baseplate could cause it to warp.

THIRD APPOINTMENT:

The vertical dimension is established and the teeth are selected.

Materials Needed:
  1. Large flat spatula
  2. #7 wax spatula
  3. Boley gauge
  4. A selection of the maxillary and mandibular anterior teeth
  5. A plastic face bowl
  6. Tape and scissors
  7. Bunsen burner
  8. Four paper towels
Maxillary Bite Block:

The maxillary wax baseplate is inserted into the patientís mouth. The lip line is marked with the sharp end of the #7 wax spatula. The baseplate is removed. The large spatula is heated over the Bunsen burner and placed on the flat incisal of the ridge-form wax bite block. The wax is melted to the mark on the bite block, and the excess wax on the flat spatula is wiped clean on the paper towels.

The bite block is reinserted into the patientís mouth and re-evaluated. The maxillary lip should be slightly over the incisal of the wax bite block in most cases.

When this is correct, the anterior midline is established in the wax with the #7 spatula. The maxillary frenum and center of the nose are evaluated. The patient should be facing you. The center line is placed where it lines up with the septal cartilage of the nose. This usually corresponds with the anterior frenum.

If the midline is different then the frenum, then the process should be re-evaluated. Always go with the center of the nose. The patient will not see the frenum.

The Mandibular Bite Block:

The mandibular wax bite block is tried in the mouth. The patient closes slightly to give some indication of where the excess wax needs to be removed. The wax bite blocks are removed and shaped with the hot large spatula to better conform to the bite. The posterior portion of the maxillary bite wax can be shortened with the hot spatula to allow more room for the patient to close his mouth.

Vertical Measurement:

Two pieces of tape are cut with a pair of scissors to leave a point at the end. One piece of tape is placed on the tip of the patientís nose. The other piece is centered and placed on the patientís chin. The Boley gauge is used to measure the distance between the two pieces of tape.

The patient wets his lips and barely touches them together. The measurement is taken. The patient repeats the process and barely touches his lips together. Another measurement is taken. It should match the first one. If it doesnít match, another measurement is taken.

When the measurement is found, the Boley gauge is closed three millimeters. This is the vertical measurement. The maxillary and mandibular wax bite blocks are inserted into the patientís mouth and measured. The wax bite blocks are usually too high.

The high spots on the bite blocks should be noted and removed. The large, flat spatula is heated and applied to the mandibular occlusal and incisal surfaces of the wax bite block to lower the vertical dimension of the wax.

The vertical dimension of the maxillary bite block can only be lowered in the posterior area. This should not be done unless there is no more room on the mandibular bite block to remove more wax. You do not want to lose the lip line.

The wax bite blocks are reinserted into the patientís mouth and evaluated. The mandibular wax bite should touch the maxillary bite wax all the way around and be slightly lingual to it. If there are discrepancies, strips of wax can be added. When the patient bites down, the bite blocks should meet evenly.

The Boley gauge, still closed three millimeters, is placed against the pieces of tape. If the gauge shows the bite to be open, more wax needs to be removed from the mandibular wax bite block. When the gauge is correct and the wax bite blocks are meeting each other, you are ready for the bite registration.

The Bite Registration:

The patient should practice opening and closing with the bite blocks in place. To establish centric occlusion, the patient should swallow and close. The bite is held in place and marked with a #7 spatula. The mark should go from the maxillary wax bite to the mandibular wax bite in the molar area.

The wax bite blocks are removed from the patientís mouth and glazed over the Bunsen burner flame for a second. Then the glazed bite blocks are reinserted into the patientís mouth. The patient bites down in centric to match the previous marks in the posterior molar area. The glazed bite blocks adhere to each other and are removed as one piece from the patientís mouth.

The #7 spatula is heated and run along the maxillary and mandibular wax seam to seal the two sides together. The stone models are placed in the bite locks and observed. The retromolar pads should be the same distance apart on both sides, and the two stone models should be centered.

If the stone models are not correct, the patient did not bite down correctly. If so, the bite blocks are pulled apart and smoothed over. The bite blocks are reinserted and the patient goes through the swallowing and bite sequence.

When the patient is doing this correctly, the bite blocks are removed, and re-glazed. Then they are reinserted. The patient is told to swallow and bite down. The bite blocks are removed and checked again.

The difference between centric and relative occlusion is not an issue here. The patient will bite down where he feels comfortable. The attempt is always made to find the centric occlusion, but the patient may find he cannot hold centric occlusion and instead slips into relative occlusion. This is probably a reflection of how he bit down when he had his teeth. He simply prefers relative occlusion. It is not good to try to change this in the denture.

Selection of the Teeth:
Mould:
Trubyte Tooth Indicator:

This indicator is a guide to help you select the size and form of the anterior teeth. It is a face bowl with the nose, eyes, and mouth cut out of the hard plastic sheet. A long rectangle hole for the sliding bar on the left side measures the width of the head. The number corresponds to the millimeters on the Boley gauge.

The Trubyte Indicator is based on the theory the sizes of the teeth are directly proportional to the size of the patientís head. This seems to hold true in most cases.

The plastic bar slides and stops above the ear. The measurement is read. The corresponding millimeters are the width of the maxillary central incisor.

The length of the tooth is found by sliding a bar up the vertical rectangle hole. The sliding bar tucks in under the chin. The number is read and corresponding millimeters are the length of the maxillary central incisor.

The patientís head will be one these shapes: square, square ovoid, square tapering, or tapering. Most people are square tapering.

Now you have the width, length and shape of the maxillary central incisor. The Trubyte Bioblend Anterior Mould Guide is used here, though other mould guides can also be used. Taking the Boley gauge width and length to the teeth in the mould guide selection, the correct teeth are found.

Usually you will be given a choice of moulds that fit the Boley gauge measurements. A female patient will usually want a softer look. The longer and more rounded teeth should be selected for this. A male patient will usually prefer squarer, stronger looking teeth. The shape of the face will help here. The mould is selected in the correct face shape. Each mould is given a number and a letter. This is given to the lab along with the shade.

If immediate dentures are being made, the mould can be taken from the existing teeth. If the patient has a previous denture, the mould can be the same in the new denture. An impression is taken of the previous denture and sent to the lab.

If the patient does not like the shape of the teeth on his old denture, or he has been without teeth for years, an old photograph can be of help.

If this is an extraction case, the impression is taken before the teeth are extracted. The Trubyte Tooth Indicator is only needed when these other methods are not available.

Choosing Among Porcelain, IPN, or Plastic Teeth:

Porcelain teeth give you durability and color blends. IPN teeth give you wear and color blends, and Plastic teeth give you wear. The cost varies from a hundred and sixty dollars to four dollars and fifty cents.

Ideally, it is better to place plastic teeth in the posterior wear area. This allows the teeth to wear, as opposed to the alveolar ridge. Most people lose their teeth to periodontal disease caused from clenching their teeth. This clenching is carried over into the denture. Hard porcelain teeth transmit this pressure to the alveolar bone. Instead of the alveolar bone around teeth receding, now the alveolar bone below the denture recedes.

Porcelain or IPN teeth can be used in the twelve anterior teeth to give the patient the desired color blends and durability. The cost is higher, but the finished look is nice.

The Downside to Porcelain Teeth:
  1. Porcelain teeth do not bond well to the acrylic base of the denture. They depend on the small metal extensions on the lingual side of the teeth to hold them in the acrylic.

  2. The hardness that makes them good anterior teeth does not serve them well in the posterior region.

IPN teeth are a plastic multi-blend. They solve the two problems of the porcelain teeth, but the wear factor is still present. Wear and the patientís cleaning techniques can take the thin multi-blend veneer off the teeth. In low economic circumstances, the plastic teeth are the treatment of choice.

Shade:

Porcelain Trubyte Bioblend multi-blend teeth range from the lightest shade, #100, to the darkest shade, #118. Usually the lighter the complexion of the patient is, the lighter the tooth shade should be. People with a dark skin complexion appear to have very light teeth, but this is not the case. Their teeth are darker, but the contrast makes the teeth appear lighter.

Usually the patient will want white teeth. It is better for you to select three shades in the range he should be in and allow the patient to select one of the three. He will usually take the lightest of the three. If you allow him to view the entire shade guide, he will select the lightest shade.

The Trubyte plastic teeth range from the lightest shade, #51, to the darkest shade, #82. The average shade is #65. When the shade is difficult to determine, shade #65 is a good place to start. Also, remember that the older the patient is, the darker the teeth should be.

These may not be the patientís thoughts. The patient is thinking of how his teeth looked when he was a teenager. He is having dentures made to regain that look. It is not always nice to place dark teeth in the denture when the patient wishes to have lighter teeth.

The wax bite blocks, stone models and directions for the set up are sent to the lab.

Laboratory:

The commercial lab will set the teeth in the wax bite block using the mould and shade given to them. It is okay to do your own set up and processing of the denture, but the time involved does not generally make economic sense.

Some labs set up the maxillary anterior teeth first and complete the maxillary arch before setting up the mandibular teeth. Other labs start with the mandibular anterior teeth. It is simply a matter of preference.

Watch out for the tendency of commercial labs to set the teeth in a class I relationship when the case warrants a class II relationship.

Anecdote

A two hundred eighty-pound six-foot seven-inch man entered my office with loose protruding anterior teeth and extensive decay on his posterior teeth. X-rays revealed decayed teeth below the tissue in the posterior. His lower teeth were in a similar condition.

When the diagnosis was completed, extraction and dentures were the treatment of choice. The man was okay in the chair, but at the front desk things changed. The receptionist called for me. I arrived in time to catch the big man. We both went to the floor. My back pre-vented his head from hitting the door, but the man was unconscious on top of me. I could not move.

The man regained consciousness and allowed me to escape with a sore back. Nothing was done to the man. He simply was unable to accept the idea of having a denture. This was a Medical patient. The cost of the denture was not a concern to him.

The teeth were extracted over a period of time to give the man time to adjust. The denture was made with a class one occlusion. This was a laboratory decision. The lower anterior teeth protruded off the mandibular alveolar ridge to reach the maxillary anterior teeth. Whenever the patient tried to eat something, the denture would dislodge.

The patientís denture was remade with a class II occlusion. The mandibular teeth were over the mandibular ridge. This worked for about a year. The patient returned with a loose denture.

The maxillary anterior alveolar ridge had receded to a class I occlusion. The maxillary teeth were no longer on the alveolar ridge. The proposed reline of the denture would have left the class II condition and would not have solved the problem of the denture dislodging. So the denture was remade to a class I occlusion. This time the teeth could be placed on the alveolar ridge and were able to maintain a class I relationship. I was amazed at how quickly the maxillary alveolar bone could be absorbed in a yearís time.

FOURTH APPOINTMENT:
Materials Needed:
  1. Boley gauge
  2. Tape
  3. Scissors
  4. #7 wax spatula
  5. #2 round bur and hand piece
  6. The laboratory waxed-up teeth

The waxed-up teeth are tried in the mouth. During this process, the following areas need to be checked:

  1. The vertical is checked with a Boley gauge and tape measurement. The tape is placed on the tip of the nose and chin. The jaw is at rest, and the waxed up teeth are out of the mouth. When the moist lips barely touch, the measurement is taken between the tape points.

    The Boley gauge is shortened three millimeters. The waxed up teeth are placed in the mouth. The teeth are closed. The Boley gaugeís short measurement should reach the tape points. If they do not reach the taped points, the bite needs to be closed before the wax-up is processed.

  2. The occlusion and the alignment of the teeth are checked. The wax may need to be heated with the #7 wax spatula, and the teeth moved to the correct position.

  3. The maxillary anterior teeth should be just under the lip line in a relaxed position. A heated #7 spatula can soften the wax to allow the teeth to be moved into the correct position.

  4. The overall look of the wax-up should be evaluated.. The wax should cover the collars of the teeth. The maxillary denture should be balanced. If the teeth on one side appear to be lower or higher than the other side, this should be corrected.

  5. The patient is given the opportunity to evaluate the waxed teeth in the mouth.

    1. The patient may want a maxillary lateral turned slightly to give a natural look to the teeth.

    2. The teeth may appear too large or too small to the patient.

    3. The wax maxillary flange may seem too bulky to her lip. This is especially true with tight-lipped patients. The flange may need to be removed to allow more room for the lip. The teeth can be placed to appear as though they are coming out of the alveolar bone. The disadvantage to this procedure is the loss of retention in this area. However, the denture can still function if the post dam is sufficient.

    4. The color of the teeth may be too light or too dark. It is always better to go with the patientís recommendations when it comes to the color of the teeth. Now that he sees the teeth in his mouth, he might think that the teeth are too light.

  6. The patientís spouse or friend who may later be critical should be present at this ap pointment to give his or her input. This will save redoing the denture later.

The Post Dam:

While the wax set-up is off the maxillary stone model, the post dam can be placed. This is a groove placed with a #2 round bur across the posterior lingual palate where the soft palate meets the hard palate. The groove should be in the soft palate. The groove extends laterally from one side of the palate to other side. It lies just inside the soft palate, and it functions as the posterior end of the denture. It does not need to extend further across the palate than this junction extends laterally. This is not an acrylic rise in the post dam area, as some technicians like to make. This is a groove that leaves a ball-shaped strip of acrylic across the palate in the denture. The ball-shaped acrylic then pushes into the soft palate and seals the denture. It needs to be in the soft tissue, or it will lift the denture from the palate.

The common practice of placing a butterfly post dam is useless. It only raises the denture. The seal occurs when the denture extends into the soft palate. The ball groove takes advantage of this and insures the seal.

Over-extending the denture into the soft palate will cause the denture to dislodge, and it will also gag the patient. When the post dam is placed in the stone model, the technician will not over-extend the denture.

The corrected wax-up is sent to the lab to process the teeth into the acrylic denture. This can be done in the office, but the odors and time involved does not generally make this practical.

FIFTH APPOINTMENT

This is the INSERTION appointment. It occurs when the finished denture is back from the lab.

Materials needed:
  1. Mirror
  2. Pressure-indicating paste (PIP) and brush
  3. Large round acrylic bur and hand piece
  4. #2 round bur and #557 bur
  5. Thin articulating paper (blue or red)
  6. Kerr extrude wash
  7. Emery cloth arbor band and chuck
  8. Baldor polishing lathe.
  9. #3 Kerr pumice, small rubber bowl and a wet cloth wheel
  10. Tin oxide, polishing compounds and a large dry cloth wheel
Maxillary Denture:

The areas of possible insertion problems are the undercuts in the anterior alveolar bone in the cuspid area and the posterior maxillary tuberosity. These are undercut areas that will prevent the denture from seating.

The pressure-indicating paste is brushed on the maxillary denture in these areas. The denture is inserted slowly. When the denture meets resistance to seating, it is removed. The pressure-indicating paste will reveal the spots preventing the denture from seating.

The large, round acrylic bur is used to remove a small portion of the acrylic in the spots indicated by the paste. This requires a light touch. The idea is to keep as much undercut as possible will still being able to seat the denture.

This process is repeated until the denture seats. The post dam should fit firmly against the palate. The maxillary seal is checked by placing pressure on the anterior teeth with your finger. It should require some difficulty to break the post dam seal.

Mandibular Denture:

The areas where you may encounter insertion problems are the lingual extensions and the anterior alveolar cuspid-to-cuspid undercuts. The pressure-indicating paste is brushed on in these areas. The path of insertion for the mandibular denture is from the posterior forward over the anterior alveolar undercut.

The lingual extension of the denture picks up the mandibular lingual undercut first, slips under it, and comes forward to engage the anterior alveolar bone. This does not require heavy pressure. You are just trying to see where the acrylic needs to be removed.

The mandibular denture is removed and examined. The pressure-indicating paste will show where the denture needs to be adjusted. The large, round acrylic bur is used to remove a portion of the undercut. Pressure-indicating paste is applied, and the denture is re-inserted.

The denture will now come further forward. This is repeated until the mandibular denture slips into place. The pressure indicating paste will show the anterior undercut, but most of the adjustment is made on the lingual extension. The removal of the anterior undercut is limited. It is good to preserve as much of the undercut as possible.

When the mandibular denture seats, the denture is removed, and the lingual extensions are examined. It is not necessary to have them extend beyond the retromolar pad or extend excessively below the mandibular undercut. The mandibular denture needs to catch the mandibular undercut and come forward over the anterior alveolar bone. Excessive material below this will interfere with the muscles in the floor of the mouth.

The seal for the mandibular denture is the lingual side of the anterior alveolar bone just anterior to the tongueís plica sublingualis. This is also an area where a sore spot develops because of the constant movement of the tongue. Denture relief in this area should be done after the patient has worn the denture a day or so. Then the relief is done sparingly.

Denture Adjustments:
  1. The adjustments on the periphery acrylic of the denture are done with an emery cloth arbor band and chuck

  2. The adjustment to the interior of the denture is done with a large acrylic bur and hand piece.

  3. The adjustments to the occlusion of the teeth are done with a #2 round bur, unless you are relieving porcelain teeth. Then you would use a diamond, flame-shaped bur.

  4. Adjustment for the frenum is done with a #557 bur and hand piece.

The mandibular denture is inserted first, followed by the maxillary denture. After insertion, the following should be checked:

  1. The occlusion is checked with the thin, blue articulating paper. The areas with the heaviest blue imprints will indicate the areas the patient strikes when he occludes the denture. The most pressure should be on the posterior molar teeth in order to insure a good seal in the post dam area. The occlusion is adjusted with #2 round bur.

  2. The frenum and tissue attachments need to be relieved in both dentures.

    1. The maxillary denture usually needs both the maxillary anterior frenum and the large tissue attachments behind the cuspid alveolar bone to be relieved. The cheeks are pulled out over the teeth when the maxillary denture is in place. If the denture is displaced, the denture should be checked for a tissue attachment, and then the acrylic should be relieved in this area.

    2. The mandibular denture usually has the mandibular anterior frenum and large tissue attachments behind the cuspid alveolar bone relieved. The cheek should be pulled up over the teeth when the denture is in placed. If the denture is displaced, the denture should be checked for tissue attachments. The mandibular denture may need to be relieved in this area.

  3. The maxillary anterior flanges are checked for tightness. Patients with tight lip muscles may need a very thin flange or no flange at all. The patient needs to start with the flange to help in the retention of the maxillary denture, but it can be removed later if it proves to be uncomfortable for the patient. The muscles need to be stretched because the muscles in this area usually shrink after the teeth are removed.

  4. The lip line of the maxillary denture is checked. The teeth should follow the lip line and be slightly under the lip when the lip is relaxed.

  5. The maxillary denture should be balanced. If one side appears to be lower or higher then the other side, this should be corrected.

  6. The patient should be satisfied with the denture. He should be given instructions on how to insert the mandibular denture. The mandibular denture is inserted in the posterior below the undercuts and brought forward over the anterior alveolar bone

When all of the corrections are completed, the adjusted portions of the denture are polished. A chuck with a wet cloth wheel is inserted into the Baldor polishing lathe. Wet #3 Kerr pumice is placed on the denture rough areas.

The wet cloth wheel is run at a slow speed over the wet pumice until the grooves created from the emery cloth arbor band are smooth. The denture can handle fairly heavy pressure, as long as the denture remains wet with the pumice and the lathe is on low speed.

When the grooves are removed, the Baldor polishing lathe is turned to high to give the denture a high polish. The wet cloth wheel lightly touches the acrylic. At high speeds, it is important for the acrylic to remain wet.

Tin oxide or red rouge can add to the luster. The tin oxide is made into a paste and placed over the denture. A large dry cloth wheel lightly touches the acrylic and removes the tin oxide. A bright finish is left behind. Red rouge and other polishing compounds work in a similar manner, except the large cloth wheel touches the polishing compound first, before the denture.

All of these compounds need to be thoroughly scrubbed off the denture with soap and water before the denture is reinserted into the patientís mouth.

Possible Problems:
The maxillary denture will not seal:
  1. The posterior teeth may not be in occlusion, or not touching.
  2. The anterior teeth may be occluding first before the posterior teeth.
  3. The post dam may be on the hard palate.
  4. The maxillary denture is not touching the palate in the posterior area because the laboratory process left a void.
Solutions:
  1. The posterior denture teeth are brought into occlusion with a #2 bur and articulating paper.
  2. The mandibular anterior teeth are slightly reduced.
  3. The post dam location is checked in the mouth
  4. The void in the maxillary post dam can be checked with Kerr extrude wash-impression material. The mandibular denture is inserted. A thin layer of wash material is placed in the maxillary denture, which is then inserted into the patientís mouth. The patient closes his mouth until the impression material hardens. When the maxillary denture is removed, the impression material will show where the denture touches the palate. If the posterior section of the maxillary denture has voids, it will need to be relined before it can be inserted.
The mandibular denture will not stay seated:
  1. The posterior teeth may not be in occlusion. The anterior teeth strike first, displacing the denture.
  2. The tissue attachments are lifting the denture from the alveolar ridge.
  3. The plica sublingualis may be displacing the seal when the tongue lifts.
  4. The muscles in the floor of the mouth may be lifting the mandibular denture off the ridge.
Solutions:
  1. The mandibular denture occlusion is corrected with a #2 bur and articulating paper.
  2. The cheek is lifted to reveal tissue attachments. These are relieved with a #557 bur and/or an emery cloth arbor band.
  3. The lingual seal of the mandibular denture forward of the plica sublingualis is relieved with a large, round acrylic bur. This should be done on the tissue side of the denture, if possible, to preserve the mandibular seal.
  4. The mandibular lingual extensions may need to be reduced. This should not be done extensively until the adjustment appointment because the patient may be able to adjust to the extension.
The patient gags on the maxillary denture:
  1. The patient gags because the post dam does not seal, or a void exists in the posterior portion of the maxillary denture.
  2. The maxillary denture may extend too far into the soft palate.
  3. Occasionally, the post dam is in the correct location, but the post dam is too large.
Solution:

The pressure-indicating paste is brushed on the maxillary denture post dam, which is then inserted. The patient goes into occlusion. The maxillary denture is removed. The pressure-indicating paste will show where the post dam touches the soft palate. A large acrylic bur removes the pressure spot.

The pressure-indicating paste is reapplied to the post dam of the maxillary denture and it is reinserted. The seal should become evident upon removing the denture. The pressure spot is removed a second time. This continues until the pressure spot extends the length of the post dam, or until the seal is good.

IMMEDIATE DENTURE:

This procedure is the same as for putting in an ordinary denture, except the teeth are removed before the denture is placed. Sutures are placed if it is necessary, but the dentures will hold the tissue in place for normal extraction.

If a specialist is removing the teeth, he will need the completed denture before the patient arrives. He should be made aware that the mandibular denture is designed to enter the mandibular extension undercuts first.

There is a tendency to place the denture into undercuts when the patient is numb that become very painful to remove later when he is not numb. This makes the removal of the denture at the first adjustment appointment difficult for the patient.

The impression in an immediate denture approximates the actual size of the anterior ridge. You may need to do extensive grinding to insert the denture, or you may find the denture is off the alveolar ridge by several millimeters.

The following is necessary to insert the immediate denture:

  1. It is the posterior seal that will hold the maxillary denture in place. Therefore, the posterior teeth need to be in occlusion to force a good seal.

  2. Excessive grinding with the acrylic bur may be necessary.

  3. The bleeding from the sockets should be stopped.

    The patient needs to come back to your office the next day to relieve the undercuts and sore spots. If the teeth were extracted from healthy tissue, this will not be a difficult procedure for the patient.

Instructions for the Patient:
  1. The patient is encouraged to try eating with his dentures in place. It usually takes two weeks for the dentures to feel normal to the patient, if he continues to wear them.

  2. The patient is encouraged to leave the denture in place overnight the first night. Other than the first night, the dentures should not be left in the patientís mouth overnight. The tissues need time to relax from the daytime pressure. This will preserve the alveolar bone longer. Excessive pressure causes the alveolar bone to recede. A large number of denture patients are clenchers. This is one of the main reason people lose their teeth and alveolar bone.

YOU DO NOT WANT TO INSERT A DENTURE UNLESS THE PATIENT CAN RETURN FOR AN ADJUSTMENT THE NEXT DAY.

This is extremely important. A discouraged patient is difficult to deal with. A sore spot can become extremely painful if it is left unattended for more than twenty-four hours.

DENTURE CARE:
  1. The denture should be cleaned with a soft toothbrush, soap and water.
  2. Commercial cleaners are good.
  3. The teeth should be placed in water when left overnight. There are commercial solutions available.
  4. Adhesives should not be worn except in special circumstances. If the denture is made correctly, adhesives are not necessary.

Anecdote

An older male patient was given his maxillary and mandibular denture. He was worked through the adjustment period and did not return for six months. He came in complaining that the anterior teeth on both his upper and lower dentures had dissolved, leaving heavy horizontal grooves across the labial surface.

I looked at the denture, trying to figure out what happened. I asked him how he was cleaning his denture. He said he had used a toothbrush like I told him. The man had been scrubbing his denture extremely hard creating the grooves with the bristles in the brush. He thought the harder he scrubbed the denture the better. He had scrubbed his original teeth in a similar matter and transposed the method to his dentures. I replaced his anterior teeth.

THE FIRST ADJUSTMENT APPOINTMENT:
Materials needed:
  1. Mirror
  2. Pressure-indicating paste (PIP) and brush
  3. Large, round acrylic bur and hand piece
  4. #2 found bur and #557 bur
  5. Thin articulating paper (blue or red)
  6. Kerr extrude wash
  7. Emery cloth arbor band and chuck
  8. Baldor polishing lathe.

The patient should be encouraged to relate all of the difficulties he is having with his new denture. Older patients like to give you one complaint at a time. You may need to tell them you can remember more then one thing.

It is not a good sign when the patient brings his denture to you in a zip-lock bag. This will occur if you delay the first adjustment appointment more then twenty-four hours.

Examination of Dentures:
With dentures remaining in the mouth:
  1. The occlusion is checked with the blue articulating paper. The dentures are removed and the occlusal adjustments are made with the #2 round bur. This process is continued until the posterior teeth seat well. This is important for the maxillary denture posterior seal. The denture will seat after being in the patientís mouth overnight and change the occlusion.

  2. The cheeks are lifted to check for displacement of the denture by the tissue attachments.

With the dentures removed:
  1. The tissue and alveolar ridges are checked for sore spots. The pressure-indicating paste is applied, and the denture is reinserted. The patient occludes hard and the denture is removed and checked. The pressure-indicating paste will show where to remove the acrylic inside the denture. A large, acrylic round bur is used to remove the excess acrylic.

  2. The denture is partially inserted and the sore tissue spots are located on the denture extensions. The emery cloth arbor band is used to remove the excess.

Possible Problems:
  1. The maxillary denture falls out of the patientís mouth.

    1. The occlusion may not be correct in the post dam area.

    2. The denture may occlude the anterior teeth first and dislodge the denture.

    3. There may be a void in the denture post dam area that requires a reline to correct.

    4. The post dam may be too large or too small.

    5. The post dam may be on the hard palate, creating the void in the post dam area.

    6. The post dam may have a rise of acrylic that creates a void instead of an acrylic ball that slips into the soft palate.

  2. The mandibular denture lifts off the ridge.

    1. A tissue attachment may be lifting the denture off the alveolar ridge. The denture needs to be relieved in this area.

    2. The mandibular lingual extension may be too long. The extensions do not need to extend beyond the triangular retromolar pad distally. The extensions need to extend into the undercut to lock the mandibular denture in place, but not beyond the locking effect. This reduction should be done before the undercut is removed. Later adjustment appointments may show sore spots developing on the thin tissue over the alveolar bone in this area. These can be adjusted out until a point is reached where the patient can tolerate the extension.

    3. If the maxillary denture has acrylic voids, then it is likely that the mandibular denture also has voids. A reline may be necessary.

    4. Denture sores are relieved with topical anesthetic. A cotton tip places the topical anesthetic on the denture where the sores are located. There are many good topical anesthetics on the market. Benzodent is probably one of the oldest topical anesthetics.

    5. The mandibular denture can be kept in place with an adhesive until the patient learns to relax the muscles in the floor of his mouth. There are several good brands from paste adhesives (Fix-A-Dent) to powder adhesives (Poly Grip.)

    6. If the patient is having a difficult time adjusting to the dentures, the mandibular denture can be removed for a week. This will allow the patient to adjust to the maxillary denture first.

DENTURE RELINES:
Materials needed:
  1. Spatula and mixing pad
  2. Impression materials
  3. Krex
    Rubber base wash
  4. Large, round acrylic bur and hand piece.
  5. Articulating paper and #2 round bur
  6. Vaseline and cotton rolls
Maxillary Denture:
Preparations:
  1. The post dam and all of the undercuts in the maxillary denture need to be removed with the large acrylic bur before the impression for the reline is taken.

  2. Red compound is used to add extensions to the denture using the technique described earlier. The red compound is heated over the Bunsen burner and dripped on the acrylic. A wet glove shapes the compound. The hot compound is placed in a warm water bath for a few seconds to cool the compound. The denture is reinserted into the patientís mouth and the tissue is stretched to mold the compound.

  3. The maxillary denture is brought into occlusion with the mandibular denture. The occlusion needs to be correct before the denture will seat properly.

Mandibular Denture:
Preparations:
  1. The undercuts are removed, especially in the anterior labial area and the lingual extension areas.

  2. The red compound is added where the denture is too short. The lingual extensions may need to be added if they do not reach the undercut area.

  3. The occlusion is corrected. The molars need to come into contact first to seat the dentures. Anterior occlusion will only dislodge the denture, even after the reline.

The Impression:

The impression is taken with a rubber base wash, Kerr extrude wash, or Lee Smith Krex ZOE impression-corrective paste. The material needs to flow easily so that it fills in the voids and does not prevent the denture from seating.

Most denture labs like the rubber base washes because they are very easy to clean up. The Krex ZOE impression paste is an old technique, but it works very well in giving an accurate impression.

Krex ZOE impression paste:
  1. The denture needs to be dry.

  2. The patientís lips, the teeth and the acrylic that is not in the impression need to be coated with Vaseline to ease in the clean up from the overflow.

  3. The two parts of the Krex material are mixed. The white accelerator is one-fourth the size of the yellow base material.

  4. A thin layer is applied to the maxillary denture and the mandibular denture.

  5. The dentures are inserted, and the tissue is worked in order to place all of the tissue attachments into the impression.

  6. The patient sits forward and is advised to breathe through his nose.

  7. The impression material hardens, and the dentures are removed.

    1. The post dam may need to be released before the maxillary denture can be re- moved. The index finger is placed as far back as possible into the maxillary tuberosity. Reaching up over the lip of the denture, the denture is pulled down. The denture may need to be tipped slightly before the post dam releases the denture.

    2. The mandibular denture is lifted off the anterior alveolar bone and slid toward the posterior. You may need to move the denture back into the mouth some distance before it will be released. You will not be able to pull the denture straight up.

The dentures are sent to the laboratory to be processed. Upon receiving them back from the lab, the insertion process is the same as for a new denture.

The Psychological Evaluation of the Patient:

If the patient lost his teeth from excessive clenching and grinding, he will continue these habits in his new denture. You can expect the patient to have excessive sore spots, and it will take a long adjustment period to make the denture fit properly.

Sometimes it is difficult for the patient to adjust to a new denture. This occurs when a patient does not have an immediate denture and is allowed to be edentulous until his tissue heals. The patient becomes used to being without teeth, and his muscles shrink. He does not like the feel of the pressure from the denture against his tissues and the sore spots he must endure. The mandibular denture floats in his mouth and pinches him when he tries to chew.

This patient should be given the maxillary denture to wear first. The mandibular denture is held for a week or until the patient is comfortable with the maxillary denture. Then the mandibular denture is glued in place with one of the commercial adhesives until the patient learns to adjust. Once the patient has adjusted to the mandibular denture, the adhesives are removed. This is a good way to encourage the patient to accept his denture.

It usually takes two weeks for the patient to adjust to his denture. The patient with an immediate denture will need to wear his denture day and night for three days to adjust to them before they should be taken out at night. If the denture is not an immediate, the denture needs to be worn only the first day for twenty-four hours. After that, the tissues need to rest from the denture pressure, or else the sores will become larger, and the resorption of the alveolar ridges will become excessive.

The patient needs to be seen the next day after the denture is placed. This is very important. The denture patient becomes quickly discouraged if he is suffering or his denture is rocking when he tries to chew. This is even more acute for patients who clenched their former teeth.

Rule of the Road:

You should never seat a denture unless you can see the patient the next day.