Wittneben, J.G., Buser, D., Salvi, G.E., Bürgin, W., Hicklin, S., Brägger, U.

Purpose: Clinical studies related to the long-term outcomes with implant-supported reconstructions are still sparse. The aim of this 10- year retrospective study was to assess the rate of mechanical/technical complications and failures with implant supported fixed dental prostheses (FDPs) and single crowns (SCs) in a large cohort of partially edentulous patients.

Materials and methods: The comprehensive multidisciplinary examination consisted of a medical/dental history, clinical examination, and a radiographic analysis. Prosthodontic examination evaluated the implant-supported reconstructions for mechanical/technical complications and failures, occlusal analysis, presence/absence of attrition, and location, extension, and retention type.

Results: Out of 397 fixed reconstructions in 303 patients, 268 were SCs and 127 were FDPs. Of these 397 implant-supported reconstructions, 18 had failed, yielding a failure rate of 4.5% and a survival rate of 95.5% after a mean observation period of 10.75 years (range: 8.4–13.5 years). The most frequent complication was ceramic chipping (20.31%) followed by occlusal screw loosening (2.57%) and loss of retention (2.06%). No occlusal screw fracture, one abutment loosening, and two abutment fractures were noted. This resulted in a total mechanical/technical complication rate of 24.7%. The prosthetic success rate over a mean follow-up time of 10.75 years was 70.8%. Generalised attrition and FDPs were associated with statistically significantly higher rates of ceramic fractures when compared with SCs. Cantilever extensions, screw retention, anterior versus posterior,and gender did not influence the chipping rate.

Conclusions: After a mean exposure time of 10.75 years, high survival rates for reconstructions supported by sand-blasted, large-grit, acidetched implants can be expected. Ceramic chipping was the most frequent complication and was increased in dentitions with attrition and in FDPs compared with SCs.

Clinical Implant Dentistry and Related Research 2014; 16 (3): 356-364.