Fracture resistance and marginal adaptation of conventionally cemented fiber-reinforced composite three-unit FPDs.

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.