BIOLOGIC RESPONSES OF AUTOGENOUS BONE AND BETA-TRICALCIUM PHOSPHATE CERAMICS TRANSPLANTED INTO BONE DEFECTS TO ORTHODONTIC FORCES

This study was conducted to evaluate biologic responses of autogenous bone (particulate marrow and cancellous bone; PMCB) and beta-tricalciu m phosphate ceramics (TCPC) to orthodontic stimuli, Nine dogs served a s the experimental animals; three dogs underwent orthodontic tooth mov ement after grafting, three dogs received PMCB grafting without tooth movement, and three dogs received TCPC grafting without tooth movement , Immediately after extraction of the upper second and/or third inciso rs, the maxillary alveolar bone was resected bilaterally, Autogenous P MCB obtained from the iliac bone and TCPC were transplanted into each bone defect, Experimental tooth movement was initiated 2 to 4 weeks af ter the grafting and continued for 9 to 15 weeks, Sectional archwires with open-coil springs were used for distal movement of the upper firs t incisors into the extraction sites, Oxytetracycline and calcein were employed as bone markers, Sections of grafted areas including the tee th were prepared for light and fluorescence microscopy. The results re vealed that both autogenous bone and TCPC presented similar adaptive c hanges to the original alveolar bone without any external stimuli, TCP C exhibited more prominent biodegradative responses to orthodontic for ce in association with new cementum formation, Root resorption was als o less in the TCPC area than in the PMCB region, It is shown that TCPC is biodegradative in nature and adaptive for remodeling during orthod ontic tooth movement, This finding indicates that TCPC may be a better biocompatible alternative to autogenous bone transplanted into bone d efects subjected to orthodontic tooth movement.