Ozone Therapy Enhances Osseous Healing in Rats With Diabetes With Calvarial Defects: A Morphometric and Immunohistochemical Study

Abstract

Background: Bone healing is impaired in diabetes mellitus (DM) cases. The aim of this study is to investigate, both morphometrically and immunohistochemically, the effect of gaseous ozone on bone healing in diabetic rat calvarial defects treated with xenografts. Methods: DM was induced with 50 mg/kg intraperitoneal streptozotocin in 56 male Wistar rats. Study groups were as follows: 1) empty defect (control, n = 14); 2) xenograft (XG, n = 14); 3) empty defect treated with ozone therapy (control + ozone, n = 14); and 4) xenograft and ozone application (XG + ozone, n = 14). Critical-size defects were created in all rats. Bovine-derived xenograft was applied to XG groups. Gaseous ozone was applied on the operation day and daily for 2 weeks (140 ppm at 2 L/d, 2.24 mg). Rats were sacrificed at 4 or 8 weeks post-surgery. Total bone area, newly formed bone, and residual graft material were measured histomorphometrically. Osteocalcin and bone morphogenic protein (BMP)-2 expression was evaluated immunohistochemically. Results: Osteoclast numbers in the XG + ozone group were higher than the other groups at week 4 (P < 0.05). XG + ozone group revealed more total bone area and new bone area than the XG group at weeks 4 (P < 0.05) and 8 (P > 0.05). Residual graft materials were decreased in the XG + ozone group and the same group revealed more BMP-2 positivity compared with other groups. Osteocalcin positivity in XG groups was higher than in control groups. Conclusion: Within the limitations of this DM animal study, gaseous ozone application accelerates xenograft resorption and enhances bone regeneration, especially in the early stages of bone healing.