Purpose: This in vitro study investigated the marginal adaptation and fracture resistance of
three-unit fiber-reinforced composite fixed partial dentures (FPD) luted with two different
resin-modified glass-ionomers. Materials and Methods: A total of 48 FPDs were
constructed from the glass fiber–reinforced materials FibreKor/Sculpture, Vectris/Targis, or
the polyethylene fiber system BelleGlass/Connect (n = 16 for each brand). The
reconstructions were conventionally luted on human molars using resin-modified
ProTecCEM or Fuji Plus and then exposed to thermocycling and mechanical loading.
Results: During thermocycling and mechanical loading, cementation failed in seven of
eight FibreKor or BelleGlass FPDs and in one of eight Vectris/Targis FPDs luted with
ProTecCEM. All Fuji Plus–cemented FPDs showed no signs of damage or cementation loss.
The fracture resistance of the remaining FPDs was as follows: Vectris/Targis–ProTecCem
1,361 ± 360 N, Vectis/Targis–Fuji Plus 923 ± 207 N, BelleGlass/Connect 940 ± 155 N,
and FibreKor/Sculpture 524 ± 202 N. The marginal adaptation of the cement-tooth
interface deteriorated by 13% to 21% for all reconstructions after stress application, which
was not statistically significant. The crown-cement interface had a significantly greater
marginal gap only with the combination of FibreKor and Fuji Plus after stress simulation
(change 33%). Conclusion: Conventional cementation of fiber-reinforced FPDs can lead to
cementation loss. The marginal adaptation and fracture resistance deteriorated in
comparison to adhesively cemented reconstructions. Int J Prosthodont 2002;15:467–472.