Relationship between salivary melatonin and severity of periodontal disease.

BACKGROUND Melatonin possesses antioxidant, free-radical scavenging, and immunoenhancing properties that promote fibroblast activity and bone regeneration. The aim of this study was to examine the possible links between salivary melatonin levels and the severity of periodontal disease using the community periodontal index (CPI). METHODS Thirty-seven patients with different degrees of periodontal disease were studied. Salivary and plasma melatonin levels (by radioimmunoassay), salivary/plasma melatonin ratio, and CPI status were collected for each patient. The Spearman correlation coefficient was used to analyze relationships among variables. RESULTS Data showed a significant correlation between CPI and salivary/plasma melatonin ratios. When saliva volume was controlled for, a significant correlation (P<0.05) was found between lower salivary melatonin and a worse CPI. This finding suggests that melatonin may act as a protector against free radicals produced by inflammatory periodontal diseases. CONCLUSIONS Salivary melatonin levels varied according to the degree of periodontal disease. As the degree of periodontal disease increased, the salivary melatonin level decreased, indicating that melatonin may act to protect the body from external bacterial insults. Therefore, melatonin may be potentially valuable in the treatment of periodontal diseases, although further research is required to validate this hypothesis.