Influence of priming time and primer’s concentrations on bovine enamel bond strengths

Abstract

This study investigated the effects of priming time (5, 30 or 60 s), 10-MDP (10-methacryloyloxydecyl dihydrogen phosphate)-containing primer’s concentrations (0.5, 1, 5, 10 and 20% (w/w)) and two neutral primers (5% (w/w) of 10-MDP-Na or EDTA-2Na) on bovine enamel microtensile bond strength (μTBS) using a novel prime-and-rinse approach. After priming, the enamel surfaces were thoroughly water-sprayed and dried before resin composite was placed. There was a significant influence of primer’s concentrations and priming time on bovine enamel μTBS when 10-MDP-containing primers were used (p < 0.001), revealing the optimal priming time (30 s) and the best combination (priming with 20% of 10-MDP for 30 s). The prime-and-rinse approach might be an innovative supplement to contemporary dental adhesive procedures. The neutral primer (5% of 10-MDP-Na) produced moderate enamel μTBS on highly polished enamel surfaces, while another neutral primer (5% of EDTA-2Na) failed, suggesting that chemical bonding of 10-MDP to enamel hydroxyapatite crystallites could yield detectable bond strengths on smooth enamel surfaces.

Keywords:

• primer’s concentration
• priming time
• chemical bonding
• enamel bond strengths

Acknowledgments

This research was financially supported by the National Natural Science Foundation of China (20973152) and the Science and Technology Research Fund of Zhejiang, China (N20110565).