Once the dentist has done an oral cancer exam and checked for good health of the oral mucosa, then the patient is ready for an impression (or mold) in order to construct a complete denture. To make this impression, the dentist first prepares a tray to hold the impression material. This tray can be made in a lab from a preliminary impression or a stock tray can be modified to fit the mouth. The borders of the tray must be properly molded so that they do not protrude too high up into the cheek. If it did, then the resulting denture would constantly rub causing a sore spot. There are a number of impression materials available. The one I prefer to use is a vinyl polysiloxane. It has a rubbery consistency when set and is so accurate that I also use it for precision crown and bridge procedures. It also has a pleasant taste which can be a big factor when one has a mass of goo in their mouth. The material is mixed and placed in the mouth and allowed to set. A special plaster is poured into the resulting mold and a perfect reproduction of the patient’s gums can be produced.
The construction of a full denture starts with an impression of the gums. The dentist must first check to see if there are any suspicious lesions that could be a malignancy. X-rays should be taken to make certain that there are no tumors inside the bone. The dentist must also make certain that there are no bony undercuts which would prevent the denture from properly seating or flabby gum ridges which would not provide a stable surface for the denture to function. Any of these problems would require surgical intervention plus a healing period before final impressions could be made. The dentist must also check the condition of the gum tissue itself.
If the gums are swollen, red, and inflamed especially due to sleeping in the dentures or from smoking, then steps must be taken to relieve the inflammation. Many times, merely leaving the dentures out while sleeping for a week or two will allow the gums to heal. In more resistant cases, a tissue conditioner can be applied to the current denture. This conditioner is a resilient liner. Its soft nature can give the gums a chance to heal. Once all of the preliminary steps have been taken, the final impression can be made.