Association between the interval of worksite dental check-ups and dental and medical expenditures: a single-site, 12-year follow-up study in Japan

Objectives: The purpose of this study was to identify the effective intervals of worksite dental check-ups to reduce cumulative dental expenditures (CDEs) and cumulative medical expenditures (CMEs), based on 12 years of follow-up dental check-ups.

Setting, design and participants: A longitudinal study was conducted between 2002 and 2014 fiscal years. A total of 2691 full-time employees (2099 males and 592 females) aged 20-59 years in a manufacturing company in Japan were recruited.

Primary and secondary outcome measures: Based on the follow-up of 12-year dental check-ups, the interval of dental check-ups visits was classified into the following categories: 'Once per year' as the regular group, 'At least once per 2 years' as the subregular group and others as the irregular group. CDEs and CMEs per capita were examined by the three groups of dental check-ups interval after adjustment for sex, age, occupation and total CMEs at baseline. For sensitivity analysis, decayed teeth, missing teeth and Community Periodontal Index were added as adjustment factors.

Results: Compared with the irregular group, the pooled CDEs (including dental check-ups fee) per capita in the subregular group (OR 0.91, 95% CI 0.85 to 0.98) and regular group (OR 0.87, 95% CI 0.81 to 0.93) were significantly lower overall. The younger adults in the subregular group and younger-aged and middle-aged adults in the regular group had significantly lower CDEs. Sensitivity analysis confirmed these findings.

Conclusions: Our findings suggest that regular and subregular worksite dental check-ups were related to reduction of CDEs. It is important to promote a yearly interval between dental check-ups.