THE EXPERIMENTAL STUDY OF THE BONE REGENERATION ON RABBIT MAXILLARY SINUS GRAFTING WITH beta-TCP

Purpose: Maxillay sinus grafting is an effective treatment procedure to improve bone height in the posterior maxillar area for implant installation. Beta-tricalciumphosphate(beta-TCP) was introduced to be grafting substitute material, providing a reasonable bio-degradation time, no need for harvesting procedure. The purpose of this study is to evaluate bone healing & regeneration phase using histomorphometric and immunohistochemical analysis. Material & Methods: Sixteen rabbits were divided into 4 groups. Bi-lateral maxillary sinus membranes were elevated at each rabbits, beta-TCP was augmented in left sinus, autogenous bone was augmented in right sinus. The rabbits were sacrificed at 2, 4, 8 and 12 weeks. We investigated the bone regeneration & growth factor expression. Results: 1. The mean new bone volume formation was 28.99 +/- 6.55%, 49.54 +/- 5.47%, 69.09 +/- 8.90% in autogenous grafted area, and 22.86 +/- 5.56%, 24.00 +/- 4.09%, 34.11 +/- 3.37% in beta-TCP area at 4, 8, 12 weeks. Therefore, new bone formation in autogenous bone was significantly higher than beta-TCP (p<0.05). 2. The BMP 2/4 expression in autogenous bone grafted area was higher at 4, 8 weeks. 3. There was no difference in expression pattern of BMP-7/PDGF/VEGF during grafted bone regeneration. Conclusion: The authors we conclude that the autogenous bone graft was faster than beta-TCP in bone regeneration, and the BMP 2/4 were more important in graft bone regeneration.