Adhesive strength of fiberglass posts treated with thio-urethane-based experimental silanesVitoria Massoneto Piccolli, Carmem Silvia Pfeifer, Ana Paula Piovezan Fugolin, Marcos Cezar Pomini, Roberta Araujo De Paula Ramos, Rafael Leonardo Xediek Consani
Purpose The aim of this study was to evaluate the adhesive bond strength of fiberglass posts treated with experimental silanes based on thio-urethane and submitted to thermo and mechanical cycles. Materials and Methods Bovine roots were divided into six groups: RX-RU2 (RelyX CP + RelyX U200); PETMPHDDI-RU2 (PETMP-HDDI + RelyX U200); PETMP-BDI-RU2 (PETMP-BDI + RelyX U200); RX-RU (RelyX CP + RelyX Ultimate); PETMP-HDDI-RU (PETMP-HDDI + RelyX Ultimate); PETMP-BDI-RU (PETMP-BDI + RelyX Ultimate). One slice from each root third (n=10) was submitted to the push-out test and the values evaluated with R Program statistical analysis, while the failure pattern assessed in percentage. Results Among root thirds, RX-RU2 promoted greater strength at the cervical and apical thirds; PETMP-HDDI-RU2 showed highest values at the three thirds; and PETMPBDI-RU2 was strongest at the apical third. RX-RU presented higher strength at the apical third, and PETMP-HDDI-RU and PETMP-BDI-RU had similar values at the three thirds. In each root third, PETMP-HDDI-RU2 showed similar strength at all thirds, and similar strength at the apical third was observed for other associations. Mixed and adhesive failures predominated. Conclusion Experimental silanes promoted different bond strength values in the adhesion of fiberglass posts to the root thirds, with better results for PETMP-HDDI silane. The root region did not influence the failure pattern and most slices showed mixed (MCDP) or adhesive (ADP) failure.