Sorry if this question is very basic, but what is an overdenture? I've read about it in various places and I'm not sure how this is different than a regular denture? Are implants used with an overdenture?
There are two basic types of implant prostheses: Implant-Supported Prostheses and Implant-Retained Prostheses. Overdentures are basically another term for Implant-Retained Prostheses.
Now to further explain:
Implant-supported prostheses are single or multiple teeth that rest only on dental implants and rely solely on the implants for support. A complete arch of teeth can be replaced in this way. These prostheses are solid and usually not patient removable and are essentially similar to natural teeth.
Implant-retained prostheses are usually full arches of teeth that are replaced by dentures. However, in cases where additional retention is needed so that the dentures stay in place, implants are placed and an overdenture made. These implants have attachments that snap in to attachments on the underside of the denture and help with stability. The overdenture still rests on the gum, it is simply more stable.
In our practice, when an edentulous patient (a patient without natural teeth) asks for implants, both types of prostheses are discussed. In patients who refuse any type of removable prosthesis, an implant supported solution is created. In patients who have had removable prostheses in the past and are comfortable with the idea, overdentures are often an acceptable solution.
Usually at least two implants are needed for a lower overdenture while at least four are needed for an upper overdenture.
Discuss your feelings about removable and fixed (non-removable) restorations with your dentist. Either way, whether implant retained or implant supported, you will benefit from implants if you are missing an entire arch of teeth.