Salivary, Plasma, and Gingival Levels of Melatonin and TNF-α in Nonsmokers and Current Smokers with and without Periodontal Disease.

Aim: The aim of this study was to quantify the levels of gingival, salivary, and plasma melatonin and tumor necrosis factor-α (TNF-α) in healthy individuals and chronic generalized periodontitis patients with and without cigarette smoking habit and to investigate whether a relationship exists between melatonin and TNF-α levels in the samples.

Materials And Methods: Blood of 5 mL, 5 mL of saliva, and gingival tissue samples were obtained from 30 periodontally healthy individuals without smoking habit (HP), 30 nonsmoking patients with chronic generalized periodontitis (CP), 30 periodontally healthy individuals with current smoking habit (SHP), and 30 current smoker patients with chronic generalized periodontitis (SCP). The levels of melatonin and TNF-α in the samples were measured using commercially available enzyme-linked immunosorbent assay (ELISA) kit. The results obtained were statistically analyzed using SPSS statistical software (23.0 version).

Results: This study demonstrated the presence of melatonin and TNF-α in all the saliva, plasma, and gingival tissue samples. Gingival tissue melatonin levels were highest in the HP group and least in the SCP groups, while TNF-α levels were least in the HP group and highest in the SCP groups. No significant difference was observed between the groups with regard to salivary and plasma melatonin. An overall significant difference was also observed between the groups with regard to salivary TNF-α but not with regard to plasma TNF-α. Binary logistic regression analysis was carried out after dividing the study groups into current smokers and nonsmokers. Results revealed that a reduction in gingival melatonin and an increase in gingival TNF-α were associated with a transition from periodontal health to chronic generalized periodontitis in current smokers but not in nonsmokers.

Conclusion: This study sheds light on the anti-inflammatory actions of melatonin in the gingival tissues in states of periodontal health and disease in current smokers.

Clinical Significance: Melatonin could be used as a supplement to boost anti-inflammatory mechanisms in periodontal therapy especially in cigarette smokers.