Abstract
The purpose of this study was to observe tissue reactions to two chitosan films containing synthesized hydroxyapatite(HA) or bovine bone powder (BB). Each film was implanted under the periosteum of rabbit tibiae, and submitted to histopathological examination at 4 and 12 weeks after operation. At 4 weeks after implantation, granulation tissue with inflammatory cell infiltration around the films were observed in both groups. Granulation tissues in BB-containing films were more mature than that of the others, because inflammatory reactions were minimum in BB-containing films. In osseous tissue, fibrous bone had proliferated from cortical bones and invaded granulation tissue formed by chitosan films. At 12 weeks after implantation, BB-containing films was already absorbed,and new cortical bone was formed in implanted sites. On the other hand, in synthesized HA-containing films, apatite components encapsulated by fibrous connective tissue were still present, and numerous fibrous bones penetrated into this connective tissue. These findings suggested that apatite containing chitosan films showed good absorbency under the periosteum of rabbits tibiae. In addition, granulation tissue and fibrous connective tissue as well as HA seemed to play significant roles in osteoconduction.
