[Relationhip between diabetes and periodontal disease].

Periodontal disease is a chronic inflammatory disorder by the anaerobic bacteria invasion into periodontal tissues including gingival connective tissue, periodontal ligament, and alveolar bone. Periodontitis is classified into two types, gingivitis and periodontitis. Diabetic patients tend to suffer from periodontitis with severe alveolar bone loss caused by lowered immune reaction and delayed tissue recovering. Periodontal pathogens such as P. gingivalis lipopolysaccharide (P-LPS) and several cytokines (TNF-alpha, IL-1 and IL-6) stimulate osteoclast differentiation in gingival connective tissue. Then, alveolar bone resorption progresses and the resultant tooth loss falls oral functions. It is confirmed that the incidence of periodontitis is 2- to 3-fold higher in diabetic patients than in non-diabetic subjects. Recently, many researches demonstrated that periodontitis affected diabetic condition, in which periodontal pathogen like P-LPS and TNF-alpha possibly elevated insulin resistance by inhibiting glucose incorporation into smooth muscle cells. Clinical study revealed that serum C-reactive protein (CRP) value increased in periodontitis patients and that periodontal treatment improved the level of HbA(1C) in diabetic patients. These data indicate that periodontal pathogen influenced systemic conditions and these are partly improved by periodontal therapy. Also, periodontal pathogen possibly promotes atherosclerosis formation. Further investigation is necessary to clarify the relationship between diabetes and periodontal disease.