Influence of Type of Dental Visit on the Incidence of COVID-19 and Related Hospitalisation Among Older People in Japan.

In 2020, the coronavirus disease 2019 (COVID-19) pandemic began worldwide. We examined the association between dental visit status and the incidence of COVID-19 and hospitalisation for it among older people based on medical claims data to help reduce COVID-19 severity. The study included 170,232 people who were 75-85 years old in fiscal 2019, with fiscal 2020 and 2021 serving as the follow-up period to ascertain the status of COVID-19. Using medical claims data, we investigated four types of dental visit (no visit, only periodontal treatment, periodontal and other treatment, and only other treatment) during fiscal 2019 and the incidence of COVID-19 and hospitalisation for COVID-19 during the follow-up period. Logistic regression analyses were performed with the incidence of COVID-19 and hospitalisation for COVID-19 as the dependent variables. Of the participants, 3206 (1.9%) developed COVID-19, of whom, 559 (17.4%) were hospitalised. There was not a significant association between the incidence of COVID-19 and type of dental visit. Participants with dental visits for periodontal treatment during the baseline year had a significantly lower odds ratio (OR) for hospitalisation due to COVID-19 compared to those without dental visits (OR: 0.71, 95% confidence interval: 0.58-0.78). The results suggest that dental visits for periodontal treatment including maintenance are important not only for maintaining oral health but also for preventing severe COVID-19.