Evaluation of physical-mechanical properties of self-adhesive versus conventional resin cements

摘要

Aim: The purpose of this study was to compare the microhardness, diametral tensile strength, compressive strength and the rheological properties of self-adhesive versus conventional resin cements. Methods: Specimens of a conventional (RelyX ARC) and 3 self-adhesive (RelyX U200, Maxcem Elite, Bifix SE) types of resin cements were prepared. The Knoop test was used to assess the microhardness, using a Microhardness Tester FM 700. For the diametral tensile strength test, a tensile strength was applied at a speed of 0.6 mm/minute. A universal testing machine was used for the analysis of compressive strength and a thermo-controlled oscillating rheometer was used for the Rheology test. One-way ANOVA and Tukey’s test (α=0.05) were used for data analysis. Results: According to microhardness analysis, all the cements were statistically similar (p0.05), except for Maxcem that presented lower hardness compared with the other cements in relation to the top surface (p0.05). In the diametral tensile strength test, Relyx U200 and RelyX ARC cements were statistically similar (p0.05), presented higher value when compared to the Maxcem and Bifix cements (p0.05). The compressive strength of RelyX ARC and Maxcem Elite cements was statistically higher than RelyX U200 and Bifix cements (p0.05). Regarding the rheology test, Maxcem Elite and RelyX ARC cements showed a high modulus of elasticity. Conclusions: The self-adhesive cements presented poorer mechanical properties than conventional resin cement. Chemical structure and types of monomers employed interfere directly in the mechanical properties of resin cements.