In this article we will discuss three of the four basic types of full dentures. These are the standard dentures, the immediate dentures, and the Cu-Sil dentures. In future articles we will go into detail regarding implants, and the implant retained denture, another alternative.
The Standard Denture
Usually, the back of a standard denture ends just behind the hard bone in the roof of the mouth. This is because they require as much surface area as possible to maximize their retention and stability. In the case of patients who struggle with gagging, however, the dentist will trim the denture forward, making its base resemble more of an arch shape. This does help the gagging reflex, however, some stability is relinquished.
Standard dentures are usually made for patients who are already missing all of their teeth. The top denture depends on suction to hold it in place, and the solidity of the underlying tissues for its strength. It generally takes at least four appointments to create a set of standard dentures.
The first appointment consists of an oral examination, usually x-rays, and a set of impressions of the upper and lower edentulous (toothless) ridges (gums). These impressions are poured, using plaster, to form accurate models of the shape of the edentulous ridges. Other considerations are determined such as the coloring, size and shape of the teeth that will be used for the new dentures.
Sometimes the dentist will suggest surgical alteration of the ridges to remove excess flabby tissue which will interfere with the stability of the new denture, and sometimes to alter the shape of the underlying bone, creating a better fit. In most cases, this surgery will not be necessary, however, it may make a much more satisfactory final fit. Modifications like these are generally time and money well spent, if your dentist recommends them.
The second appointment will generally consist of determining how long to make the new teeth, deciding the plane of the tooth setup. A guideline is, when you smile, the teeth should be parallel to a line between the pupils of your eyes, and the correct relationship of the upper and lower teeth so that when you bite together, the upper and lower teeth line up correctly. This is done using a loose fitting denture base and a rim of wax to determine the position of the teeth.
Both upper and lower wax rims are carefully adjusted to fit properly in the patient’s mouth so he can speak correctly without the wax rims clicking together, and so that the upper and lower rims fit together squarely. Preferably, the wax rim should be visible a little below the patient’s lip when the lip is at rest. When the patient smiles, the position of the lip is marked in the wax to help the lab decide which set of teeth are suitable for this patient. Once these relationships are accurate, the rims are sent to the lab where they are used to fabricate the wax try in. The third appointment is for the wax try in. The laboratory has returned the loosely fitting tray from the second appointment with the true final plastic teeth lined up along the outer edge of the wax rim. The wax try in appears just like a real denture, other than the foundation sits loosely on the gums, and the teeth are implanted in wax instead of what will be plastic.
This gives your dentist a chance to see how the denture looks and works before the final setup. During this step things can still be readily adjusted, by sending the denture back to the lab, where a skilled technician can re-melt the wax and set the teeth to a different specification.
Your dentist will undoubtedly refit your denture as many times as necessary until the teeth look and function as they should. When everything is ideal, the denture will be sent back to the lab to be processed and finished. The old loose fitting foundation and all the wax will be discarded, and replaced by a snug fitting plastic denture base.
The fourth appointment is usually the insertion date when the patient walks out of their dentist’s office with new dentures. The plastic does tend to contract during processing, so some adjustment is typically required before they will maintain the suction that you might associate with a new denture.
Immediate Dentures Immediate dentures, also often referred to as temporary dentures, are in fact made prior to the natural teeth being extracted. The patient goes into their dentist’s office with natural teeth, and walks out the same day with dentures. Their teeth are extracted, and a prefabricated denture is inserted immediately over the unhealed gums. The patient is still numb from the extractions, and really won’t feel any discomfort until later at home. Usually, most patients do not mention too much pain after their teeth are extracted and the immediate denture is inserted. The denture acts like a pressurized band aid, helping to reduce pain.
The manufacture of an immediate denture necessitates only one or two preliminary appointments before the insertion date, depending on how many natural teeth the patient has left to extract, ect. They generally work out relatively well. When the patient leaves, he certainly looks much better than when he came into the office. The bone that maintained the original teeth is still intact, and the gum tissue is secure. For at least the first week, the immediate denture will remain secure and fairly well retained.
For the most part of cases, immediate dentures simply become permanent dentures, however there are large amount of issues related with immediate dentures that may cause the patient to desire new dentures made after their gums have fully healed, in about a year. These issues account for the alternative name, temporary dentures.
If the patient has more than one or two remaining front top teeth, it is frequently unfeasible to do a wax try in. The denture teeth are placed in about the same position as the natural teeth before extraction. Even though the denture teeth will be straight, their position may not be perfect because there is no way to preview them as the dentist normally would with a standard denture. For this reason, not everyone will be happy with the finished look of their immediate denture, and may desire a new one at the end of about a year.
After all of the natural teeth have been extracted and the immediate denture is placed, there will be a rather quick loss of the bone that used to hold the natural teeth in place. By the end of about three weeks, enough bone has been lost that there is a great deal of space between some parts of the denture and the healing gums. This leads to ever-increasing slackness and sore spots which must be removed recurrently. In some offices, the dentist will include a free temporary “soft” reline at about one month after the extraction and insertion date. This is an uncomplicated way to tighten the denture against the gums, and since the material is a bit rubbery, and frequently medicated, it makes the denture much more comfortable until enough healing has taken place to do a permanent “hard” reline, usually at an additional charge.
At the end of 4 to 6 months, the immediate denture must be relined with the same acrylic that the denture base was made from originally. The hard reline is a separate procedure and the cost is normally not included in the original price of the immediate denture. Consequently, the immediate denture ends up costing a little more than the standard denture when the price of the reline is taken into account. The hard reline defines the official transition of the immediate denture into a standard denture.
Cu-Sil Dentures There are a significant amount of problems connected with full dentures, and not everyone can effectively bear them. In many cases, false teeth are not particularly useful due to maintenance or steadiness problems. On this basis, even a single healthy tooth left in place can steady an otherwise unstable full denture.
Just of late it has become feasible to develop a denture leaving an outlet here and there to allow any remaining teeth to thrust through without destroying the suction which usually holds the denture in place. The Cu-Sil denture has these outlets for any remaining natural teeth. These outlets are encircled by a gasket of stable silicone rubber which hugs the natural teeth and allows the rest of the denture to rest against the gums giving the advantage of suction in addition to the wonderful stability presented by the immobility of the natural teeth.
CuSil dentures help stabilize loose teeth and may even prolong their lives. It is also simple to replace lost natural teeth with the CuSil denture, and the denture can be relined like any other standard denture. The versatile CuSil denture can finally, should the need arise, be altered into a regular full denture if the patient one day loses all the natural teeth.