Trabecular Bone Response to Titanium Implants with a Thin Carbonate-Containing Apatite Coating Applied Using the Molecular Precursor Method
Tohru Hayakawa, PhD / Kenichi Takahashi, DDS / Masao Yoshinari, PhD / Hiroyuki Okada, DDS, PhD / Hirotsugu Yamamoto, DDS, PhD / Mitsunobu Sato, PhD / Kimiya Nemoto, DDS, PhD
Purpose: The influence of thin carbonate-containing apatite (CA) coating on the trabecular bone response to titanium implants was investigated. Materials and Methods: Thin CA coatings were deposited by a new method known as the molecular precursor method. Using a precursor solution composed of an EDTA-calcium complex, a CA film was deposited on the titanium surfaces. Uncoated and CA-coated titanium were placed in the trabecular bone of the left and right femoral condyles of 16 rabbits. After implantation periods of 2, 4, 8, and 12 weeks, the bone-implant interface was evaluated histologically and histomorphometrically. Results: Histologic evaluation revealed new bone formation around the uncoated and CA-coated implant surfaces after only 4 weeks of implantation. After 12 weeks, mature trabecular bone surrounded all implants. At 4 and 8 weeks of implantation, no difference existed in bone contact between uncoated and CA-coated implants. After 12 weeks of implantation, the CA-coated implant group showed a significantly higher percentage of bone contact than the uncoated implant group. Discussion and Conclusion: The present study demonstrated that thin CA coatings applied using the molecular precursor method showed greater bone-to-implant contact during the healing phase than uncoated controls. The results were similar to those observed with implants with calcium phosphate coatings.