[Biodegradable ceramic as a bone graft substitute followed by orthodontic tooth movement]

This study was performed to evaluate the histological changes during remodelling of autogenous PMCB (particulate marrow and cancellous bone) and TCPC (beta-tricalcium phosphate ceramic) when transplanted into the jaw bone defects, and also to investigate the possibility of orthodontic tooth movement on them. Twenty dogs were used in this study. Following extraction of the upper 2nd and 3rd incisors, or only the 2nd incisor, maxillary alveolar bones were resected bilaterally. Autogenous PMCB obtained from the ilium and TCPC (Synthograft, Miter, Inc. U.S.A.) were grafted in each resected area. Nine dogs were sacrificed without applying the orthodontic force, whereas the rest of dogs were sacrificed after applying orthodontic force. Sectional arch wire with open coil spring was placed between the upper 1st incisors for tooth movement. Applications of orthodontic force were started anywhere from the 2nd to the 8th week following the grafting and continued for different experimental periods. Sections of maxillary bone including the grafted areas were prepared for light microscopy. It was observed that Synthograft area showed better organization than the bone graft area initially. However, later around the 8th week, both graft materials were well organized. The Synthograft was well accepted by the host tissue. The Synthograft filled area reconstructed the bony architecture more similar to the alveolar bone than the bone graft area. In addition, the radiological findings also showed orthodontic tooth movement through the PMCB and the Synthograft areas. Capability of orthodontic tooth movement at the Synthograft areas without any undue result is of significant clinical value. Thus in view of above points in conclusion it is suggested that, TCPC is a competent substitute for PMCB in filling up alveolar bone defects, even, in cases where orthodontic tooth movement is desirable.