The
purpose of this clinical study was to evaluate the long-term outcome of
3-unit anterior fixed partial dentures (FPDs) made of fiber-reinforced
resin composite (FRC), and to identify design factors influencing the
survival rate.

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.