Overdentures Versus Fixed Prostheses

Two concepts of prosthetic restorations exist for the edentulous jaw: the fixed prosthesis (mostly screw retained) and the overdenture. It appears that overdentures are preferably placed in old patients and in compromised situations. Since the eighties, a series of studies - including longterm results - have demonstrated the reliability of treatment with fixed prostheses for the upper and lower jaw. An increasing number of studies on mandibular overdentures supported by only two implants give evidence of the effectiveness of this treatment modality. Comparable data for maxillary overdentures are still missing. While dentists tend to base the selection of the prosthetic design on the number of implants that can be placed, other criteria have to be considered: esthetic appearance, facial morphology and restitution of lost hard and soft tissues, costs of implant-prosthodontic treatment, stability of the prostheses, complications and adjustments required, assessment of individual needs. From an economic point of view overdentures supported by two to four implants might be preferred. Prosthetic methods in general and related to implants are not evidence based. They relay on clinical experiences, patients’ demands technical considerations and reports of success and failure. However, from clinical experience, well-designed clinical concepts have evolved and the benefit of the patients concerned appears to be high and obvious. The lecture will discuss the use of implants for prosthodontic rehabilitation in the completely edentulous jaw. Indications and various types of removable prostheses are presented and variations of design discussed. Biomechanical aspects of fixation and stabilization of prosthesis complete the overview