Strengthening Ceramic Surfaces With The Use Of Resin Cements Based On Thiourethane Oligomers

This study evaluated the effects of thiourethane (TU) additives on the flexural strength (sigma(f)) and elastic modulus (E-f) of a resin cement, and on a possible strengthening of ceramic restorations. Methods Two 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 (sigma(f)) and elastic modulus (E-f) of the cements were measured in three-point bending (n = 8). Biaxial flexural strength (sigma(bf)) of ceramic discs with and without cement layering were determined using a ball-on-ring setup. The sigma(bf) of cement-coated specimens was calculated at positions z = 0 (ceramic surface, bonded interface) and z = -t(2) (cement surface above ring). Data were analyzed with one-way ANOVA/Tukey test (alpha = .05). Results sigma f of AR was significantly higher than for AL and RU, and E-f was lower. The E-f of RU was significantly higher than all other groups. At z = 0, all resin-coated groups had higher sigma(bf). The sigma(bf) of RU, AR, and AL were significantly higher than EC and unfilled resin group. At z = -t(2), RU had significantly higher sigma(bf). Significance All resin cements were able to strengthen the ceramic, with the TU-modified material presenting similar results to the commercial material.