Effects of Two Experimental Models of Osteoporosis on Alveolar Bone: Histopathologic and Densitometric Study

Aim: The aim of this study was to compare two different models of osteoporosis radiographically and histopathologically and evaluate the effect of osteoporosis on alveolar bone. Methods: Twenty two rats were involved in this study. Study groups are; Control (C, n=6) group; retinoic acid-induced osteoporosis group (EG-1, n=8) and bran bread-induced osteoporosis group (EG2, n=8). Retinoic acid induced osteoporosis was created by intraperitoneal injection of 70 mg/kg retinoic acid for 15 days. Bran bread induced osteoporosis was created with the replacement of normal rat diet to the bran bread for 45 days. The study period began with the osteoporosis induction. Rats were kept alive for 15 days and then sacrificed. Femurs and mandibles of the rats were extracted and digitalized radiographs were taken. Density measurements were performed on radiographs. Mandibles of the rats were examined morphologically and histopathologically. Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL) and TRAP staining were performed on histological slides. Results: There was no significant difference in RANKL expression among groups (p>0.05). Femoral density was lower in the EG2 group than those of the others (p<0.05). Mandibular density was lower in the EG2 group than EG1 (p<0.05). TRAP positive osteoclast numbers were higher in the EG2 group than other groups (p<0.05). Conclusion: Within the limitations of this study, we concluded that bran bread induced osteoporosis may decrease mandibular bone density and may increase osteoclastic activity but both model of osteoporosis did not affect alveolar bone morphology.