Technical complications of implant-supported fixed partial dentures in partially edentulous cases after an average observation period of 5 years

Objectives: The purpose of this prospective long-term study was to evaluate the incidence of the most common technical problems, namely screw loosening, screw fracture, fracturing of veneering porcelain and framework fracture in implant-supported fixed partial dentures (FPDs), and assess the survival and success rate (event-free survival) after 5 years of function. Materials and methods: In 76 partially edentulous patients, a total of 205 3i-implants (machined surface) were placed and restored with 112 implant-supported FPDs (46 single crowns, 81 splinted crowns, seven FPD bridges and 23 FPDs with cantilevers). The survival rate of FPDs supported by implants was 94.5% (CI- 95: 90.1-98.8) after an average observation period of 5 years. The success rate (event-free survival) of the FPDs was 80% (CI-95: 87.3-72.7). After an observation period of 5 years the cumulative incidence of screw loosening was 6.7% (CI-95:1.8-11.5), the cumulative incidence for screw fracture was 3.9% (CI-95:0.1-7.7). Fracture of the veneering porcelain occurred in 5.7% (CI- 95:1.2-10.2) of all FPDs. Fracturing of the suprastructure framework was rare (1%; CI- 95:0-2.9). The overall complication incidence after 5 years was highest in the group of FPDs with cantilever, which showed the lowest success rate 68.6% (CI-95:50-87.3), followed by single crowns (77.6%; CI- 95:53.3-100) and splinted crowns (86.1%; CI- 95:59.5-100). No complication occurred in FPD bridges. Conclusion: Fixed partial dentures supported by 3i-implants showed low technical complications rates, the most common being loosening of the abutment screw. Managing these complications can cause extra amount of chair-side time and patient dissatisfaction.