Bond strength of resin cements in semi-indirect restorations: an in vitro study

Abstract

Objective: To evaluate in vitro the bond strength of different resin cements, both conventional and self-adhesive, used in semi-indirect restorations. Material and Methods: Bovine incisors (n = 48) were randomly divided into four groups (n = 12) according to the resin cement used for cementation: G1 - RelyX ARC (3M), G2 - RelyX U200 (3M), G3 - NX3 (Kerr), and G4 - Maxcem Elite (Kerr). Restorations were performed using the semi-indirect technique, simulated by molding the prepared cavities in the bovine incisors. Bond strength (MPa) was measured using a push-out mechanical test in a universal testing machine. The data were statistically analyzed using one-way ANOVA followed by Tukey’s test (α = 0.05). Results: Multiple comparison analyses demonstrated that the RelyX U200 (3M) group, a self-adhesive resin cement, exhibited the highest bond strength values (4.01 ± 1.28). A statistically significant difference was observed only in comparison with the Maxcem Elite (Kerr) group (2.73 ± 0.95) (p ≤ 0.015). Conclusion: Cement formulation influenced bond strength. Although the self-adhesive resin cement RelyX U200 showed the highest values, another self-adhesive cement (Maxcem Elite) showed lower bond strength than the conventional cements (RelyX ARC and NX3), indicating variability within the same cement category.

KEYWORDS

Adhesiveness; Dental cements; Dental materials; Dental restoration, permanent; Resin cement