Biomechanical Comparison of Biomimetically and Electrochemically Deposited Hydroxyapatite-Coated Porous Titanium Implants

Purpose: The purpose of this study was to investigate the effects of biomimetically and electrochemically deposited hydroxyapatite on the fixation of an implant with bone tissue. Materials and Methods: Implants were separated into 3 groups: roughened group, biomimetically deposited calcium-phosphorus (BDCaP) group, and electrochemically deposited hydroxyapatite (EDHA) group. We randomly inserted 90 implants into the femurs of 45 rabbits. After 2, 4, and 8 weeks, the femurs were retrieved and prepared for removal torque tests (RTQs) and field-emission scanning electron microscopy observation. Results: During the test period, the EDHA. group showed significantly greater RTQ values than did the roughened group and BDCaP group. The BDCaP group failed to increase the RTQ values compared with the roughened group. Field-emission scanning electron microscopy observation showed that the amount of attached bone tissue on the EDHA-coated implant surface was more than that on the roughened and BDCaP-coated implant surfaces during the test period. Conclusion: The electrochemical hydroxyapatite coating contributes to the fixation between bone and implant compared with the roughened surface, whereas the biomimetic calcium-phosphorus coating has little effect on the fixation. (C) 2010 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 68:420-427, 2010