A Study of the Effects of Anodized Titanium Implants

Objectives: The purpose of this study was to inspect the characteristics of oxide layer formed on titanium implant by anodic oxidation(anodization), and to evaluate the bone healing capacity of anodized implant. Methods: Screw shaped implant and plate formed specimens were made of commercially pure titanium. Group 1 samples had machined surface and other three experimental specimens were anodized under constant voltage ; 190V(Group 2), 230V(Group 3), 270V(Group 4). The characteristics of specimens were inspected in five categories ; surface morphology, surface roughness, thickness, crystallinity, and the chemical composition of oxide layer. Screw shaped implants were installed in rabbit tibiae and the removal torque values were measured after 4 weeks healing period. Results: Anodized titanium implants have porous oxide layer, and there are increase in both size and number of pores, as the anodizing voltage gets higher. The Ra value of Group 4 samples was higher than that of Group 1 and 2 samples (p<0.05). Group 3 showed the difference compared with Group 1 (p<0.05). At higher anodizing voltage, thicker oxide layer that has crystalline(anatase) TiO2 and contains the composition of electrolyte(Ca, P) is formed. The removal torque values were 12.6Ncm(Group 1), 27.0Ncm(Group 2), 24.6Ncm(Group 3), and 43.2Ncm(Group 4). Group 4 showed highest values than the other groups in significant level(p<0.05). Conclusion: Anodized titanium implants showed faster bone healing in the short healing period than the turned titanium implants in this experimental model.