The effect of Phase 1 periodontal treatment on the salivary RANKL/OPG ratio in severe chronic periodontitis

Background: RANKL and OPG play an important role in bone resorption. The $\frac{RANKL}{OPG}$ ratio increases in periodontal disease. The present study was conducted to evaluate the effect of Phase 1 periodontal treatment on the salivary $\frac{RANKL}{OPG}$ ratio in patients with severe chronic periodontitis.

Materials and methods: Saliva samples were collected from 13 patients with severe chronic periodontitis and 14 healthy controls at baseline and then four weeks after the treatment using unstimulated spitting. The salivary levels of RANKL, OPG and $\frac{RANKL}{OPG}$ ratio were investigated using the ELISA method.

Results: The findings of this study showed that the mean $\frac{RANKL}{OPG}$ ratio was significantly higher in the patients with periodontal disease than in the healthy controls (P=0.001). Also, the $\frac{RANKL}{OPG}$ ratio was significantly higher in the patients with a higher mean CAL (P=0/004). The comparison of the salivary $\frac{RANKL}{OPG}$ ratio in patients with periodontal disease before and four weeks after the treatment showed a significant reduction in this value four weeks after the periodontal treatment (P=0/001).

Conclusion: The results of this study showed a direct relationship between the $\frac{RANKL}{OPG}$ ratio and the severity of periodontal disease. Phase 1 of periodontal treatment was found to be effective in reducing the $\frac{RANKL}{OPG}$ ratio. In other words, the $\frac{RANKL}{OPG}$ ratio can be a good predictor of treatment success. Further long-term studies with larger sample sizes are required for confirming these results.