title: Melatonin expression in periodontal disease.
abstract: OBJECTIVE
  It was the purpose of this study to examine the relationship between periodontal diseases and melatonin level.
  
  
  METHODS
  Forty-six patients with periodontal disease, together with 26 age- and gender-matched healthy controls, were included. Periodontal status was assessed using the Community Periodontal Index. Plasma and salivary melatonin levels were determined using specific commercial radioimmunoassays, whereas lymphocyte subpopulations (e.g. CD3, CD4, CD8, C19 and natural killer cells) were analyzed using flow cytometry.
  
  
  RESULTS
  Patients with periodontal disease had significantly (p < 0.001) lower plasma (9.46 +/- 3.18 pg/mL) and saliva (2.55 +/- 0.99 pg/mL) melatonin levels than healthy control patients (14.33 +/- 4.05 and 4.22 +/- 0.87 pg/mL, respectively). A biphasic relationship was observed between plasma melatonin levels and Community Periodontal Indices. The plasma melatonin level was reduced in patients with a lower Community Periodontal Index value (1 or 2) and increased in patients with a higher Community Periodontal Index value (3 or 4). Salivary melatonin parallels the changes of plasma melatonin. The higher the Community Periodontal Index, the older the patient and the higher the total lymphocyte counts. CD4 concentrations also increased as the disease worsened.
  
  
  CONCLUSIONS
  The results obtained from this study suggest that melatonin could act as a protective function in fighting periodontal infection. However, further studies in this area are encouraged.
authors.affiliation: Department of Special Care in Dentistry, School of Dentistry, University of Granada, Granada, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Gómez-Moreno
authors.forename: A
authors.initials: A
authors.lastname: Cutando-Soriano
authors.forename: C
authors.initials: C
authors.lastname: Arana
authors.forename: P
authors.initials: P
authors.lastname: Galindo
authors.forename: J
authors.initials: J
authors.lastname: Bolaños
authors.forename: D
authors.initials: D
authors.lastname: Acuña-Castroviejo
authors.forename: H-L
authors.initials: HL
authors.lastname: Wang
mesh_terms: D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural; D018655:Lymphocyte Count; D008297:Male; D008550:Melatonin / Q000032:analysis / Q000097:blood* / Q000502:physiology; D008875:Middle Aged; D010512:Periodontal Index; D010518:Periodontitis / Q000097:blood / Q000378:metabolism*; D012471:Salivary Proteins and Peptides / Q000032:analysis
chemical_list: D012471:Salivary Proteins and Peptides; D008550:Melatonin