title: Gingival, plasma and salivary levels of melatonin in periodontally healthy individuals and chronic periodontitis patients: a pilot study.
abstract: BACKGROUND
  Periodontal disease is an inflammatory condition affecting tooth supporting structures in which dysregulated immune response and oxidative stress mediate tissue destruction. Melatonin, the pineal gland hormone is a regulator of circadian rhythm, an antioxidant and an immunomodulator. Previous studies have shown lowered melatonin levels in saliva, plasma and gingival crevicular fluid (GCF) of patients with periodontal disease. Till date no study has assessed the melatonin levels in gingival tissues.
  
  
  METHODS
  Five healthy individuals and 15 chronic periodontitis patients were recruited for this pilot study. 5ml of whole saliva, 2 ml peripheral blood and gingival tissue samples were obtained from each individual at 8.00 am in fasting state. Melatonin assay was performed with a commercially available ELISA kit. Statistical analysis was done to assess the difference in mean melatonin levels among the groups.
  
  
  RESULTS
  No statistically significant difference was found in mean melatonin levels between healthy individuals and chronic periodontitis patients in saliva (p=.266) and plasma (p=.933) samples, whereas in gingival tissue samples (p=.015), the melatonin levels were significantly lowered in chronic periodontitis patients compared to healthy individuals.
  
  
  CONCLUSIONS
  This study demonstrates the presence of melatonin in gingival tissue. Furthermore, melatonin levels are lowered in gingival tissues of chronic periodontitis patients.
authors.affiliation: Associate Professor, Department of Periodontology, Faculty of Dental Sciences, Sri Ramachandra University , Porur, Chennai, Tamilnadu, India .
authors.forename: Thodur Madapusi
authors.initials: TM
authors.lastname: Balaji
authors.affiliation: Formerly, Assistant Professor, Department of Biochemistry, Sri Ramachandra University , Chennai, India; Presently, Associate Professor, Department of Biotechnology, Pondicherry Medical University, India .
authors.forename: Hannah Rachel
authors.initials: HR
authors.lastname: Vasanthi
authors.affiliation: Professor and Head, Department of Periodontology, Faculty of Dental Sciences, Sri Ramachandra University , Porur, Chennai, Tamilnadu, India .
authors.forename: Suresh Ranga
authors.initials: SR
authors.lastname: Rao
keywords: Antioxidant; Chronic periodontitis; Gingiva; Melatonin; Plasma; Saliva