Bond strength of glass fiber posts cemented with bulk-fill flowable composite resin

Abstract

This study evaluated the adhesive bond strength of glass fiber posts cemented with bulk-fill flowable resin in endodontically treated teeth, and the results were compared with those of glass fiber posts cemented with resin cement. Forty bovine incisor roots were selected and randomly divided into 2 groups (n?=?20). The external surfaces of the roots were coated with a molding material. The canals were prepared, and then the fiber posts (Whitepost no. 2, FGM) were cemented with either resin cement (Allcem, FGM) (n?=?20) or bulk-fill flowable resin (Opus Bulk Fill, FGM) (n?=?20). Ten roots (n?=?10) of each material were subjected to push-out and pull-out tests (EMIC DL 2000, Brazil) under compressive and tensile loading, respectively; a 50?N load cell and a constant crosshead speed of 0.5?mm/min was used for both tests. The testing data were analyzed using multifactorial analyses of variance two-way ANOVA and the Tukey test (α?=?0.05). Two skilled operators determined the failure modes of the samples using a stereomicroscope at 40× magnification with a 2.5D analysis. For push-out bond strength, there were no statistically significant differences between the root thirds in the bulk-fill flowable resin group and those in the resin cement group (p?=?0.536). However, there were statistically significant differences (p?<?0.001) among the root thirds within the same group. For pull-out bond strength, there were no statistically significant differences between the groups (p?=?0.739). Therefore, the bulk-fill flowable resin exhibited similar results to those of the resin cement from the same manufacturer in terms of the cementation of glass fiber posts, which suggests that bulk-fill flowable resin is a suitable alternative material for cementation.