Strengthening ceramic surfaces with the use of resin cements based on thiourethane oligomers

Abstract

This study evaluated the effects of thiourethane (TU) additives on the flexural strength (σf) and elastic modulus (Ef) of a resin cement, and on a possible strengthening of ceramic restorations.MethodsTwo TUs (ARomatic and ALiphatic) were added at 0 (control—EC) or 20 wt% to photopolymerizable resin cements. RelyX Ultimate (RU) was the commercial control. Flexural strength (σf) and elastic modulus (Ef) of the cements were measured in three‐point bending (n = 8). Biaxial flexural strength (σbf) of ceramic discs with and without cement layering were determined using a ball‐on‐ring setup. The σbf of cement‐coated specimens was calculated at positions z = 0 (ceramic surface, bonded interface) and z = −t2 (cement surface above ring). Data were analyzed with one‐way ANOVA/Tukey test (α = .05).Resultsσf of AR was significantly higher than for AL and RU, and Ef was lower. The Ef of RU was significantly higher than all other groups. At z = 0, all resin‐coated groups had higher σbf. The σbf of RU, AR, and AL were significantly higher than EC and unfilled resin group. At z = −t2, RU had significantly higher σbf.SignificanceAll resin cements were able to strengthen the ceramic, with the TU‐modified material presenting similar results to the commercial material.