effect of nanocrystalline hydroxyapatite socket preservation on orthodontically induced inflammatory root resorption

objective: orthodontically induced inflammatory root resorption (oiirr) is considered to be an important sequel associated with orthodontic tooth movement (otm). otm after socket preservation enhances the periodontal condition before orthodontic space closure. the purpose of this study is to investigate the histologic effects of nanobone®, a new highly nonsintered porous nano-crystalline hydroxyapatite bone on root resorption following otm. materials and methods: this experimental study was conducted on four male dogs. in each dog, four defects were created at the mesial aspects of the maxillary and mandibular first premolars. the defects were filled with nanobone®. we used the niti closed coil for mesial movement of the first premolar tooth. when the experimental teeth moved approximately halfway into the defects, after two months, the animals were sacrificed and we harvested the area of interest. the first premolar root and adjacent tissues were histologically evaluated. the three-way anova statistical test was used for comparison. results: the mean root resorption in the synthetic bone substitute group was 22.87 ± 11.25×10-4 mm2 in the maxilla and 21.41 ± 11.25×10-4 mm2 in the mandible. statistically, there was no significant difference compared to the control group (p>0.05). conclusion: the use of a substitution graft in the nano particle has some positive effects in accessing healthy periodontal tissue following orthodontic procedures without significant influence on root resorption (rr). histological evaluation in the present study showed osteoblastic activity and remodeling environment of nanoparticles in nanobone®.