Melatonin: potential functions in the oral cavity.
BACKGROUND
Melatonin is synthesized and secreted by the pineal gland and other organs. The pattern of melatonin secretion is controlled by an endogenous circadian timing system and conveys information about the light-dark cycle to the organism, thereby organizing its seasonal and circadian rhythms. Melatonin has powerful antioxidant effects, functions in an immunomodulatory role, may protect against certain cancers, delays some age-related processes, stimulates the synthesis of type I collagen fibers, and promotes bone formation.


METHODS
An extensive review was made (e.g., using PubMed, Science Direct, and Web of Knowledge) of the literature.


RESULTS
Melatonin, which is released into the saliva, may have important implications for dental disorders, especially in periodontal disease. Diseases of the periodontium are known to be aggravated by free radicals and by alterations in the immune response to microorganisms that are present in plaque. In response to periodontal inflammation, the blood and salivary levels of melatonin may increase.


CONCLUSIONS
Melatonin may play a role in protecting the oral cavity from tissue damage that is due to oxidative stress, and it may contribute to the regeneration of alveolar bone through the stimulation of type I collagen fiber production and the modulation of osteoblastic and osteoclastic activity.
Cutando
Antonio
A
Department of Special Care in Dentistry, School of Dentistry, University of Granada, Granada, Spain. acutando@ugr.es
Gómez-Moreno
Gerardo
G
Arana
Carlos
C
Acuña-Castroviejo
Darío
D
Reiter
Russel J
RJ
D000975:Antioxidants / Q000502:physiology; D006801:Humans; D008550:Melatonin / Q000096:biosynthesis / Q000276:immunology / Q000502:physiology*; D009059:Mouth Diseases / Q000276:immunology / Q000378:metabolism; D010012:Osteogenesis / Q000502:physiology; D018384:Oxidative Stress / Q000502:physiology; D010510:Periodontal Diseases / Q000276:immunology / Q000378:metabolism*; D012463:Saliva / Q000737:chemistry
D000975:Antioxidants; D008550:Melatonin