The effect of different concentrations of topical ozone administration on bone formation in orthopedically expanded suture in rats

The aim of this study was to investigate the effects of different concentrations of ozone (O-3) therapy on bone regeneration in response to an expansion of the inter-premaxillary suture in rats. Forty-eight Wistar rats were randomly divided into four groups (n = 12). In groups I, II, and III, 1ml of O-3 at 10, 25, and 40 A mu g/ml was injected at the premaxillary suture, respectively. In group IV (control group), 1ml of saline solution was injected at the same point during the expansion procedure for 5 days. Bone regeneration in the suture was evaluated histomorphometrically. The area of new bone and fibrotic area, the number of osteoblasts and osteoclasts, and the amount of vascularity were measured and compared. The density of the newly formed bone in the expansion area was measured by using cone beam computed tomography. Data were analyzed using the Kruskal-Wallis one-way analysis of variance and post hoc Student-Newman-Keuls tests. New bone area, fibrotic area, osteoblast and osteoclast numbers, and the amount of vascularity were significantly higher in experimental groups compared with the control group (P < 0.001). The density of newly formed bone (P < 0.001), new bone formation (P = 0.009), number of capillaries (P < 0.001), number of osteoclasts (P = 0.016), and number of osteoblasts (P < 0.001) in the maxillary sutures were highest in the 25 mu g/ml O-3 group compared with the other experimental groups and control group. The application of O-3 therapy can stimulate bone regeneration in an orthopedically expanded inter-premaxillary suture during both the expansion and retention periods.