Effect of CH-treatment of titanium on bone formation around implants

Objectives: To evaluate the effect of titania fabrication to titanium (Ti) implant surface with chemical and heat treatment (CHT) on bone formation around implants. Methods: Fabrication of titania to Ti implant surface was achieved by immersing Ti cylinder (2 mm in diameter, 4 mm in length whose center part of the cylinder was narrowed to a diameter of 1 mm) into 3 mass% H₂O₂ solution at 80 ˚C for 3 hrs and subsequent thermal treatment at 400 ˚C for 1 hr (CHT group). The CH-treated Ti cylinder, further soaked in a simulated body fluid for 36 hrs was regarded CHT-HAp group, which is known to induce the formation of thin apatite layer on the Ti surface (Wang et al., 2004). Those two treated (CHT and CHT-HAp groups) and non-treated control cylinders (control group) were implanted into 8-week-old male rat (n=15) tibiae. 28 days after implantation, all animals were sacrificed and undecalcified ground sections at a 70 µm thickness, perpendicular to the long axis of the implant were fabricated (n=10 in each group). The sections were stained and the mean bone-implant contact ratio (BCR) in each group was calculated for quantitative evaluation of the bone regeneration around the implants. The mean BCR in the three groups were submitted for statistical analysis. Results: The mean BCRs of the CHT, the CHT-HAp, the control groups were 43.1+/-12.7, 70.0+/-14.9, 77.6+/-13.2 %, respectively (p<0.0001: ANOVA). The mean BCRs of the CHT and the CHT-HAp groups were significantly higher than that of the control group (p<0.0001, respectively: Scheffe). Conclusions: These results suggest that CHT and CHT-HAp promotes bone regeneration around Ti cylinder, implanted in the rat tibiae. This study was supported in part by grant-in-aids for scientific research from the Ministry of Education, Science, Sports, and Culture of Japan (#17390516).