ABSTRACT
BACKGROUND:Nano-hydroxyapatite as a surface modification material that is bonded to the surface of the zirconia ceramics upon sintering at high temperature can improve bone-inducing activity and bone bonding strength of the zirconia ceramics. Moreover, the sintering temperature is crucial for performance and bonding of the composite. OBJECTIVE:To detect the shear strength of nano-hydroxyapatite ceramics coating bonded to zirconia ceramics at different sintering temperatures. METHODS:Nano-hydroxyapatite slurry was prepared using sol/gel technology. Thereafter, 20 zirconium green bodies were coated with nano-hydroxyapatite slurry and randomly divided into four groups. Then, the specimens were put into non-pressure sintering furnace and sintered at 1 300, 1 400, 1 500, and 1 550℃, respectively. At last, we measured the shear strength of al the specimens after sintering by universal testing machine, and analyze the type of fractures. RESULTS AND CONCLUSION: With the rising of sintering temperature, the shear strength of the specimens was gradualy increased, and there were significant differences between the four groups [(4.04±1.19), (6.60±0.95), (16.51±1.93), (80.47±19.31) MPa,P < 0.05]. Within the scope of 1 550℃, the sintering temperature was positively relative to the shear strength of specimens. These findings indicate that in the certain temperature range, the higher the sintering temperature, the greater the shear strength of the bonding interface between zirconia and nano-hydroxyapatite. When the sintering temperature is 1 550℃, the shear strength of the bonding interface is the highest.