Abstract: Abstract：　Objective　To compare the 3D printed zirconia implants and computer aided design-computer assomated manufacture (CAD/CAM) zirconia implants and pure titanium implants in the differences in osseointegration in animals, and evaluated the osteointegration performance of zirconia implants for zirconia implantation in bones. Methods　Six Beagle dogs were selected, and randomly planted 3D printed zirconia implants, CAD/CAM implants and titanium implants in tibias, 20 for each material. Success rate and osteointegration performance of zirconia implants were evaluated 8 weeks later. Osseointegration performance was compared with titanium implants. The observational indicators of this study were success rate of the bone implant, reverse torque test, bone-to-implant contact rate, and bone density around the implants. SPSS17.0 software package was used for statistical analysis of the data. Results　The success rates of the three groups of bone implants were all 100%.The reverse torque values of CAD / CAM zirconia implant group were all greater than 35 N; the reverse torque values of zirconia implant group by 3D printed technology were all greater than 35 N; the reverse torque value of 2 implants in the titanium implant group was between 20 and 35 N, and the reverse torque value of 8 implants was greater than 35 N. Histological observation findings: The rates of bone osseointegration without marrow cavity of 3D printed zirconia implants, CAD/CAM zirconia implants and pure titanium implants exhibited （66.35±6.64%）、（61.32±10.41%）and（58.88±25.10%）, respectively. The rates of bone osseointegration with marrow cavity of 3D printed zirconia implants, CAD/CAM zirconia implants and pure titanium implants displayed （49.57±5.04%）、（42.21±18.58%）and（38.45±23.27%）, respectively. And the average rate of bone osseointegration of 3D printed zirconia implants, CAD/CAM zirconia implants and pure titanium implants revealed （58.94±6.31%）、（53.56±8.77%） and（48.31±20.76%）, respectively. Moreover, the bone density around 3D printed zirconia implants, CAD/CAM zirconia implants and pure titanium implants demonstrated (60.59±7.31%), (58.50±6.36%) and (58.18±14.80%), respectively. There was no significant difference after data analysis (P> 0.05). Conclusions　Zirconia implants have the similar osseointegration ability as pure titanium implants, and can form close direct bone contact. Therefore, zirconia implants may be an optional material for dental implants.

Key words: Osseointegration, Zirconia implant, Non-decalcified implant bone section