ABSTRACT
Periodontitis causes various diseases, including arterial sclerosis, cardiac infarction, diabetes, aspiration pneumonia, and tooth loss, all of which lower the quality of life of individuals. Risk factors of periodontitis include a lack of oral care and low secretion of saliva due to stress, accompanied by excessive activity of the sympathetic nervous system and low secretion of serotonin and melatonin. Serotonin may improve the ability of individuals to manage stressful events, while melatonin may enhance the regeneration of tooth tissues. Saliva contains melatonin, epidermal growth factor, and nerve growth factor. The production and secretion of serotonin and melanin involve epigenetic mechanisms, i.e., gene expression resulting from chemical responses with genome sequences. Warm-hearted maternal attitudes to babies during infancy and a positive lifestyle, including a well-balanced diet, moderate aerobic exercise, and a purpose in life, as well as warm-hearted human relations, may also improve the ability of individuals to manage stressful events. This improvement in stress management may be linked to beneficial epigenetic alterations that promote the secretion of sufficient amounts of serotonin and melatonin, which may in turn contribute to the prevention and treatment of periodontitis and the regeneration of tooth tissues.