Periodontitis is closely associated with diabetes mellitus and has a diabetic complication-like appearance. In an in-vivo study performed using obese rodents, we first found that insulin resistance in the gingiva, in addition to that in the retina and glomeruli of the kidney, was induced via vascular inflammation even prior to diabetes mellitus. Furthermore, inflammation caused by oxidative stress was observed in the vascular endothelial cells of the gingiva. Oxidative stress caused by elevated production of reactive oxygen species (ROS) in the periodontal tissues is associated with impaired cellular functions, delayed gingival wound healing, impaired periodontal tissue regeneration, and compromised implant osseointegration.

Clinical studies have shown that patients with type 2 diabetes mellitus have a significantly higher frequency of morphological abnormalities in the gingival capillaries. The glycemia control status was found to be correlated with the periodontal inflammatory surface area (PISA) even after adjusting for the full-mouth plaque control level. Intensive diabetes care resulted in a significant reduction in the severity of periodontal inflammation and of the probing pocket depth. These clinical findings provide evidence for a bidirectional relationship between diabetes mellitus and periodontal disease.

Chronic kidney disease is associated with the major complications of diabetes mellitus. Further research is needed to better understand the association between periodontal disease and chronic kidney disease. Available evidence to date suggests that a correlation may exist between the oral health of patients with end-stage renal failure and their systemic condition, including survivability. A 3-year longitudinal study found insufficient oral hygiene as a significant risk factor for mortality, and involvement of periodontal disease in the development of the malnutrition-inflammation-atherosclerosis (MIA) syndrome, which is a significant risk factor for survival in patients undergoing dialysis. The findings suggest that dental interventions, such as instructions for maintaining oral hygiene and periodontal therapy, may potentially improve the overall prognosis of patients undergoing hemodialysis.

Future research in the field of periodontal medicine should consider how dental professionals could potentially contribute to the promotion of overall health by controlling periodontal disease.

We conducted a web-based questionnaire survey of members of the Japanese Society of Periodontology in 2022 to determine their smoking status and factors associated with their provision of smoking cessation support to their patients. The responses of 1,396 respondents (corresponding to a response rate of 11.2%) were analyzed. Of the respondents, 945 (67.7%) were non-smokers, 414 (29.6%) were former smokers, and 37 (2.7%) were current smokers. Of the current smokers, 13 (35.1%) were exclusively cigarette smokers, 15 (40.5%) exclusively used heated tobacco products (HTPs), and one (2.7%) smoked a water pipe; of the remaining smokers, 4 were dual users of cigarettes and HTPs, 3 were dual-type HTP users, and one smoked both cigarettes and e-cigarettes. Of the participants, 240 (18.3%) consistently provided smoking cessation support to their patients with periodontal disease, whereas 656 (50.1%) did so only when they felt it was necessary. Three factors were significantly associated with the dentists providing smoking cessation support (P < 0.05): age ≥ 50 years, score on the Kano Test for Social Nicotine Dependence of ≤ 9, and awareness of the relationship between smoking and severe periodontal disease. Among dental hygienists, there were no statistically significant factors associated with the provision of support to patients for smoking cessation. Hence, dentists were more likely to provide support for smoking cessation, but only when they were aware of the impact of smoking. It is therefore necessary to disseminate correct knowledge and awareness among dental practitioners about the need to provide smoking cessation support to their patients and to create an environment that facilitates provision of smoking cessation support by dental practitioners and their staff.