IADR Abstract Archives
Bone Regeneration of Canine Peri-implant Defects Using Synthetic Carbonated Apatite
Objectives: The main inorganic component of human bone is not stoichiometric hydroxyapatite (HAp), but carbonate apatite (CO3Ap) which contains 4-8wt% of carbonate in apatitic structure. By this reason, we focused on synthetic CO3Ap as effective bone substitutes for bone regenerative therapy. We have developed novel CO3Ap bone graft substitutes (Cytrans Granules) by using dissolution-precipitation reactions. In this study, we aimed to evaluate the efficacy and biocompatibility of CO3Ap in peri-implant bone defect model in dog.
Methods: [Study A] 2 standardized 5×5×4 mm box-shaped defects with dehiscence of 5 mm were bilaterally created, and φ3.8 mm dental implants were placed in distal of defects. [Study B] φ3.8 mm dental implants were placed in center of distal and mesial sockets of dog lower premolars. The extraction sockets were randomly divided into CO3Ap, HAp, b-TCP and negative control. After healing period of 12 weeks, histological evaluation was performed. Animal experimental protocols were approved by the Institutional Animal Care and Use Committee of Hamri Co., Ltd.
Results: [Study A] Histological evaluation revealed a relatively higher augmented area for CO3Ap groups compared to others. Regarding the bone-to-implant contact, CO3Ap was superior to all other groups at 12 weeks. [Study B] The result of histomorphometric assessments was 80.6% in CO3Ap group, 82.8% in b-TCP group, 41.9% in HAp group and 64.1% in control group. Epithelial downgrowth area was less in the CO3Ap group (0/4 site, 0 mm2) than b-TCP group (3/4 site, 0.18 mm2), HAp group (4/4 site, 0.28 mm2) and control group (3/4 site, 0.51 mm2). These results suggest that CO3Ap promote connective tissue ingrowth and thus minimize epithelial downgrowth.
Conclusions: This finding suggested that CO3Ap is useful and safe bone substitute for use in peri-implant bone defect. Composition similar to the bone may be an advantageous factor for artificial bone substitute.
Methods: [Study A] 2 standardized 5×5×4 mm box-shaped defects with dehiscence of 5 mm were bilaterally created, and φ3.8 mm dental implants were placed in distal of defects. [Study B] φ3.8 mm dental implants were placed in center of distal and mesial sockets of dog lower premolars. The extraction sockets were randomly divided into CO3Ap, HAp, b-TCP and negative control. After healing period of 12 weeks, histological evaluation was performed. Animal experimental protocols were approved by the Institutional Animal Care and Use Committee of Hamri Co., Ltd.
Results: [Study A] Histological evaluation revealed a relatively higher augmented area for CO3Ap groups compared to others. Regarding the bone-to-implant contact, CO3Ap was superior to all other groups at 12 weeks. [Study B] The result of histomorphometric assessments was 80.6% in CO3Ap group, 82.8% in b-TCP group, 41.9% in HAp group and 64.1% in control group. Epithelial downgrowth area was less in the CO3Ap group (0/4 site, 0 mm2) than b-TCP group (3/4 site, 0.18 mm2), HAp group (4/4 site, 0.28 mm2) and control group (3/4 site, 0.51 mm2). These results suggest that CO3Ap promote connective tissue ingrowth and thus minimize epithelial downgrowth.
Conclusions: This finding suggested that CO3Ap is useful and safe bone substitute for use in peri-implant bone defect. Composition similar to the bone may be an advantageous factor for artificial bone substitute.