Effect of HTPB-TAC primer on the bond strength of a resin cement to zirconia.

Abstract

Objective: The purpose of this study was to evaluate the effect of Hydroxyl-terminated polybutadiene grafting with Trimellitic anhydride chloride (HTPB-TAC) primer on microtensile bond strength of a resin cement to zirconia ceramics. Materials and methods: Fully sintered zirconia blocks were primed with either HTPB-TAC primer or Alloy primer® then bonded to resin composite block using a resin cement. The blocks bonded with resin cement without primer served as a negative control. Each cemented block was cut into 8 microbars (1x1mm). Pool of 48 microbars for each condition was prepared. Half of microbars in each condition were investigated with a microtensile bond strength test. The others were subjected to thermocycling for 10,000 cycles (5 to 55°C) before testing. Data were analyzed with two-way ANOVA and Games-Howell test at α = 0.05. Results: The microtensile bond strength values were significantly affected by primer and thermocycling without their interaction. The microtensile bond strength of HTPB-TAC primer and Alloy primer showed significantly higher bond strength compared to the non-primed specimen (p<0.05) while those of HTPB-TAC primer had no statistical difference from Alloy primer (p>0.05). The bond strength of all primers including non-primer was drastically decreased after thermocycling. Conclusion: HTPB-TAC primer could promote the bond strength of resin cement to zirconia.