[Success rates of implant supported prostheses in partially edentulous patients--Part II]

The use of dental implants is an established procedure for the treatment of partially edentulous patients. However, there is only little knowledge about the prosthetic outcome of implant-supported restorations. The purpose of this prospective long-term study was to evaluate success rates of implant-supported restorations in partially edentulous patients three years after loading. The study group consisted of 76 patients (47 females, 29 males) with 214 3i-implants (machined surface). 64 implants were used to support single crowns, 81 implants for 81 splinted crowns (36 units), 17 implants for seven bridges and 61 implants for 23 cantilevered bridges. For prosthesis construction, UCLA-Abutments were used. Screw connection was achieved by gold-alloy-coated square head screws and titanium hexagon head screws. Clinical follow-up visits were performed at the time of prosthesis insertion, three months, six months, one year, two years and three years after insertion of the prosthesis. The evaluation of the superstructures was performed according to the success criteria defined by Walton (1998). The success rate for the prosthetic reconstructions was estimated at 84.9% 36 months after loading. The success rate was 88.6% for fixed partial dentures, 86.4% for single crowns and 76% for cantilevered bridges. Technical problems included screw loosening, screw fractures, framework fractures, veneering material failures and failures because of implant loss and following remake or modification of the superstructures. Since mainly technical complications such as screw loosening and screw fractures were causing problems, the connection between implant and superstructure should be improved.