In the present study, we show a positive association between smoking habit and high dental cost. Smokers were more likely to incur dental care costs than non-smokers among the users of dental and medical check-up services. Warnakulasuriya et al. have shown that oral health risk such as oral cancer, periodontal disease, tooth loss, implant failure, and dental caries have a strong association with tobacco smoking . The cost of smoking exceeds the cost of periodontal therapy . However, we could not obtain information about daily tooth cleaning habits, such as the frequency of using dental floss or other types of teeth cleaning tools. The result of the present study is consistent with that of a report that current smokers were less likely to consult a dentist in the past year than those who never smoked . There was no significant association between children’s exposure to secondhand smoke and dental expenditure using the Medicaid database . It is also necessary to consider the impact of secondhand smoke on medical and dental costs.
In our results, smokers were more susceptible to progressed dental caries, missing teeth, and uncontrolled acute inflammation. Therefore, the rate of recalls and need for medications to control acute dental inflammation was higher in smokers. Non-smokers were more likely to receive the first consultation, including the Basic Periodontal Examination, and the scaling procedure as part of the routine dental examination. Some reports showed that, compared with never smokers, current smokers were less likely to exercise daily preventive care .
Based on the Act on Ensuring Medical Care for the Elderly, the Specified Health Checkup was started in 2008. In 2016, the targeted population was 53.6 million individuals with basic insurance, aged 40 to 74 years old; the total average rate of those who received this checkup was 51.4%. Although the consultation rate increased over time, the financial situation of the insurer remained variable. More than 75% of insured individuals underwent specific checkups in the health insurance society, but less than 50% of insurers received checkups in the National Insurance Association [23[. Individuals who have not undergone routine medical checkups are included in the list.
The data of participants in this study were derived from the administrative claims database and specific checkups. The advantage of a real-world database, such as the medical claims database used in our study, is that it can provide diagnosis and treatment information even if a participant switches to another medical institution [24[. Moreover, we have used a propensity score matching method to adjust for potential confounding variables, such as lifestyle between the two groups.
There are some limitations to this study. We could only consider the medical and dental service under health insurance due to the characteristics of the administrative claims database. Individuals who did not visit the dental clinic were not analyzed. Therefore, medical expenses may have been overestimated. Free dental treatments, such as whitening, orthodontic treatment, implants, and aesthetic dentistry, were not included in this analysis. According to a survey conducted by the Ministry of Health, Labour and Welfare, the implementation rate of specific checkups was 47.4% in all Japan Health Insurance Associations. Hence, the utilization of medical and dental services may have been overestimated considering the total population. The information regarding pharmacy claims was not included in this database. Thus, the cost of healthcare excluded medication costs. We could not distinguish between former smokers and non-smokers without data on the smoking period. Jeong reported that electronic cigarette vaping and conventional cigarette use had a significant association with periodontal disease rates . However, we were unable to identify the type of cigarettes used in this study. Socioeconomic status is a well-known risk indicator for dental disease . The study population comprised insured individuals who were enrolled in the Japan Health Insurance Association, Osaka branch. However, we could not evaluate the economic situation in each household. Adults 75 years or older with high medical and dental costs could not be included in this study, as they usually transfer to the medical care system for the elderly.
According to National Health and Nutrition Survey, smoking habits are declining among both men and women since 2016 (30.2% in men and 7.2% in women). Although smokers are at a higher risk of oral pain, smoking cessation significantly decreases the risk . The adverse effects of smoking on oral health are often reduced by smoking cessation. As there exists a strong dose-dependent association between smoking and tooth loss, dentists play a crucial role in tobacco control .
In summary, this study suggests that smokers have higher dental costs, most often due to acute illness. Our findings support the call for public policies to promote non-smoking activities. Promoting regular dental visits is one strategy to help people prevent and treat oral disease in early stages.