Effects of sandblasting, H sub(2)SO sub(4)/HCl etching, and phosphate primer application on bond strength of veneering resin composite to commercially pure titanium grade 4

This study investigated the effects of surface treatments on the bond strength of a resin composite to a commercially pure titanium. The bonding surfaces of all titanium specimens were ground with 1,000-grit silicon carbide paper and then subjected to one or more of these surface treatments: sandblasting with alumina (sand), etching with 45wt% H sub(2)SO sub(4) and 15wt% HCl (SH-etchant) at 70 degree C for 10 min, and/or phosphate primer (MDP-primer) application. Specimens not subjected to any surface treatment were used as controls. After resin composite veneer placement and 24-h water immersion, the shear bond strengths of the specimens in descending order were: sand/SH-etchant/MDP-primer, sand/SH-etchant/no primer, no sand/SH-etchant/MDP-primer, sand/no etch/MDP-primer, no sand/SH-etchant/no primer, sand/no etch/no primer, no sand/no etch/MDP-primer, no sand/no etch/no primer. Scanning electron microscope observations revealed that sandblasting and SH-etchant created many micro- and nanoscale cavities on the titanium surface. Results showed that a combined use of sandblasting, SH-etchant, and MDP-primer application had a cooperative effect on titanium bonding.