[The influence of surface conditioning on the shear bond strength of La-Porcelain and titanium].

Objective\ To determine the influence of different surface conditioning methods on bonding strength of low fusing porcelain (La_Porcelain) and titanium.Methods\ The surface of the samples were sandblasted for 2 min with 80～250 μm Al\-2O\-3 or coated for two times with Si_couple agent or conditioned by pre_oxidation. The shear bond strength was examined by push_type shear test with a speed of 0 5 mm/min in a universal testing machine. Scanning electron microscopy (SEM) and electron probe micro_analyzer (EPMA) were employed to explore the relationship between bonding strength and microstructures, as well as the element diffusion at the interface between porcelain coating and titanium when heated at 800℃.Results\ Bonding strength was not statistically different (P0 05) after sandblasting with Al\-2O\-3 in particle size ranged from 80 μm to 250 μm. When a Si_couple agent was used, bond of porcelain to titanium was significantly lower (P0 05). The shear bond strength of the porcelain to the pre_oxidized titanium surface remained unchanged after heating (P0 05). The SEM results revealed integrity of porcelain and titanium. Conclusion\ La_Porcelain showed a small effect of surface coarseness. Sandblasting the titanium surface with 150～180μm Al\-2O\-3 can be recommended as a method for better bonding between La_Porcelain and titanium. The Si_couple agent coating and pre_oxidation of titanium surface is unnecessary.\;