Effect of Freeze-Dried Allografts on the Orthodontically Induced Root Resorption

Objectives: To determine the effect of Demineralized Freeze-Dried Bone Allografts on the amount of orthodontically induced root resorption when the biomaterial is placed in extraction site in the proximity of the tooth undergoing displacement toward the mentioned bone allograft. Methods: Third premolars were extracted in upper and lower jaws of four dogs to prepare sixteen extraction sites. The mentioned sites were randomly divided into control and experiment groups equal in both jaws. Experimental sites were prepared for inserting biomaterials i.e. DFDBA (CenoBone®). Second and fourth premolars were pulled together by a closed NiTi coil spring. After eight weeks, the samples were sacrificed and the amount of orthodontic tooth movements was measured. A histomorphometric study was conducted to measure the resorptive lacunae. Wilcoxon Signed-rank statistical test was performed for the purpose of comparison. Results: The amount of orthodontic tooth movement (OTM) had not significant difference (p<0.05) between Control (2.5±1.16 mm) and Experimental (2.7±1.8 mm) groups. The histomorphometric study revealed less root resorption in the Experiment (0.12±0.09 square mm) versus the Control group (0.26±0.12 square mm) (p<0.05). Conclusion: According to the data, it seems that administration of Demineralized Freeze-Dried Bone Allografts as a biomaterial used for preservation of extraction sites can reduce root resorption induced by orthodontic tooth movement. The role of biologic molecules in the aforementioned group of bone substitutes may have a significant influence on the controlling of root resorption.