Complete dentures replace all the teeth in a given arch, while a partial denture fills in the spaces created by missing teeth and prevents other teeth from changing position.
Candidates for complete dentures have lost most or all of their teeth or have major periodontal disease or unrestorable cavities in most or all of the teeth in the arch. A denture improves chewing ability and speech when compared to having no teeth, but in general will never let you chew as well as your natural teeth. As it provides support for facial muscles, it will greatly enhance the facial appearance and smile.
Complete or full dentures are made when all of your natural teeth are missing. You can have a full denture on your upper or lower jaw, or both.
Complete dentures are called “immediate” or “conventional” according to when they are made and when they are inserted into the mouth. Immediate dentures are actually made from models obtained while you still have some teeth and are inserted immediately after the extraction of those remaining teeth. An advantage of immediate dentures is that the wearer does not have to be without teeth during the healing period. Doing so however requires a certain amount of guesswork as to what shape the bone and gums will be once the teeth are removed. Additionally, the bone and gums likely will shrink over time, especially during the period of healing in the first six months after the removal of teeth. When this happens the denture becomes looser fitting as the denture does not change shape to remain in close proximity to the gums. In order to change the shape of the denture and get the fit tighter, a rebase or reline is done, adding a new layer of acrylic to the inside of the denture. A conventional denture is what is made anytime the denture is made in the absence of teeth and all healing has already occurred. Advantages of making the denture after healing include a better fit and for a longer period of time as well as the ability to do what is called a “wax try-in”. In a wax try-in the teeth which will be used in the denture are set into a pink wax denture which enables seeing exactly what they will look like and how they fit against the teeth in the opposing arch. If they are too short, too long, not the right color or don’t fit the other teeth well, the wax can be melted, and the teeth repositioned until it is just what you want. This cannot be done for an immediate denture since there are teeth still in the way.
An overdenture is a removable denture that fits over a small number of remaining natural teeth or implants. The natural teeth must be prepared to provide stability and support for the denture.