52 patients (26 females, 26 males) received 60 indirectly made FRC FPDs, using pre-impregnated unidirectional glass fibers, requiring manual wetting, as framework material. FPDs were surface (n = 48) or hybrid (n = 12) retained and mainly located in the upper jaw. Hybrid FPDs had a combination of retainers; i.e. crown at one and surface retention at the other abutment tooth. Surface FPDs were either purely adhesively retained (n = 29) or with additional mechanical retention (n = 19). Follow-up period was at minimum 5 years, with check-ups every 1–2 years. Six operators were involved, in three centers in the Netherlands, Finland and Sweden. Survival rates, including repairable defects of FPDs, and success rates were determined.
Kaplan–Meier survival rate at 5 years was 64 % (SE 7 % ). For the level of success, values were 45 % (SE 7 % ) and the estimated median survival time 58 (SE 10.1) months. For surface FPDs, additional mechanical retention did not improve survival significantly. There was a trend towards better survival of surface FPDs over hybrid FPDs, but differences were not significant. Main failure modes were fracture of the FPD and delamination of veneering composite.
A success rate of 45 % and a survival rate of 64 % after 5 years was found. Fracture of the framework and delamination are the most prevalent failure modes, especially for surface FPDs.