Repairing The Alveolar Ridge And The Bone Defect Around Dental Implant By Gelatin-apatite-minocycline Nanocomposit Combined With Platelet-rich Plasma

Objective To investigate the feasibility of gelatin-apatite-minocycline nanocomposite combined with platelet-rich plasma (GEL–HA–M/PRP) to repair alveolar ridge and the bone defects around dental implants.Methods (1)six healthy dault mongrel dogs were divided into there groups with the completely random method .The2nd, 3rd,4th premolars were extracted from both sides of the mandible of each dogs.Three months after extraction,3 implants with 4 mm×11 mm were separately implanted in each side of the mandibule. At the same time,a bone defect with the size of 1.5 mm in width×4.0mm in depth was created around each implant neck. Autogenous bone, GEL–HA–M / PRP was grafted in one of the bone defects respectively,and one defect without materials grafted was used as blank control. Two of the dogs were sacrificed at 4,8,12 weeks respectively after the implantation, and X-ray and histopathologic examinations were taken out.(2)Four healthy dault mongrel dogs were divided into two groups with the completely random method. The 2nd, 3rd,4th premolars were extracted from both sides of the mandible of the each four of healthy mongrel dogs.Autogenous bone, GEL–HA–M/PRP was grafted in one of the socket ,and one socket without materials grafted was used as blank control. Two of the dogs were sacrificed at 4,8 weeks respectively after the implantation, and X-ray and histopathologic examinations were taken out.Results (1)six dogs were all in good health ,and the wounds all achieved the primary healing,.There are more new bone formation in experimental group than other groups,and the GEL–HA–M/PRP nanocomposite was fully adsorbed. In autogeneous bone groups, we could see mature bone and a few new bone formation,bone resorption exist. In blank groups, fibrous connective tissue almost filled the bone defect, and only a small amount of bone.There was good osseointegration between the bone and implant in the experimental groups but only was fibrous connection in the blank group.(2)All the sockets achieved good healing,there were varying degrees bone regeneration in GEL–HA–M/PRP group 4,8,12 weeks after operations,The materials was gradually absorbed; In autogeneous bone groups,there were many new bone formation, And bone resorption phenomenon exists;there were a little bone regeneration in blank groups,in which more fibrous tissue grown into the sockets,the new bone in Gel-HA-M/PRP groups was significantly higher than the other 2 groups in each period.Conclusion (1)The combination of gelatin-apitate-minocycline nanocomposite and platelet-rich-plasma can repair bone defect around the implant effectively.( 2)There are more new bone formation in experimental group, GEL–HA–M/PRP can be used to prevent the absorption of residual alveolar ridge ,premote the new bone formation and maintain the height of alveolar ridge,providing a good conditon for denture repair later,have more clinical predications.