Effect of surface pre-treatment on durability of resin-based cements bonded to titanium

Titanium has in recent years become a material of great opportunities in dentistry and orthopedics. In this study, we searched for a method to effectively pre-treat titanium as part of an adhesive luting and/or resin-veneering procedure.

Ti plates were treated with two different solutions of hydrochloric acid (0.1, 1N), 37wt% phosphoric acid or kept untreated (control). The tensile bond strength of the composite cement (Panavia Fluoro Cement, Kuraray) to the untreated and pre-treated Ti plates was determined without and after 20,000 thermo-cycles. XPS was used to chemically analyze the effect of the three Ti pre-treatments, as well as the interaction of 10-methacryloxydecyl dihydrogen phosphate (10-MDP; functional monomer of Panavia Fluoro Cement) with Ti treated with 1N HCl.

Although no significant difference in immediate tensile bond strength was measured, thermo-cycling significantly decreased the bond strength of all experimental groups except for Ti treated with 1N HCl. No difference in surface roughness was found between untreated and treated Ti. XPS demonstrated that HCl effectively decontaminated Ti in a dose-dependent manner, while H(3)PO(4) was strongly adsorbed on the Ti surface. While the latter potentially inhibits adsorption of the phosphoric groups of the functional monomer 10-MDP, Ti pre-treated with 1N HCl improved the adsorption of 10-MDP as compared to untreated Ti.

It is concluded that 1N HCl effectively pre-treats Ti in order to make it more receptive to resin, while H(3)PO(4) should better not be used.