Comparison between a bulk-fill resin-based composite and three luting materials on the cementation of fiberglass-reinforced posts.

OBJECTIVES

This study verified the possibility of cementing fiberglass-reinforced posts using a flowable bulk-fill composite (BF), comparing its push-out bond strength and microhardness with these properties of 3 luting materials.

MATERIALS AND METHODS

Sixty endodontically treated bovine roots were used. Posts were cemented using conventional dual-cured cement (CC); self-adhesive cement (SA); dual-cured composite (RC); and BF. Push-out bond strength ( = 10) and microhardness ( = 5) tests were performed after 1 week and 4 months of storage. Two-way repeated measures analysis of variance (ANOVA), 1-way ANOVA, -test, and Tukey tests were applied for the push-out bond strength and microhardness results; and Pearson correlation test was applied to verify the correlation between push-out bond strength and microhardness results (α = 0.05).

RESULTS

BF presented higher push-out bond strength than CC and SA in the cervical third before aging ( < 0.01). No differences were found between push-out bond strength before and after aging for all the luting materials ( = 0.84). Regarding hardness, only SA presented higher values measured before than after aging ( < 0.01). RC and BF did not present 80% of the maximum hardness at the apical regions. A strong positive correlation was found between the luting materials' push-out bond strength and microhardness ( < 0.01, R = 0.7912).

CONCLUSIONS

The BF presented comparable or higher push-out bond strength and microhardness than the luting materials, which indicates that it could be used for cementing resin posts in situations where adequate light curing is possible.