Wider Dental Care Coverage Associated with Lower Oral Health Inequalities: A Comparison Study between Japan and England

Countries with different oral health care systems may have different levels of oral health related inequalities. We compared the socioeconomic inequalities in oral health among older adults in Japan and England. We used the data for adults aged 65 years or over from Japan (N = 79,707) and England (N = 5115) and estimated absolute inequality (the Slope Index of Inequality, SII) and relative inequality (the Relative Index of Inequality, RII) for edentulism (the condition of having no natural teeth) by educational attainment and income. All analyses were adjusted for sex and age. Overall, 14% of the Japanese subjects and 21% of the English were edentulous. In both Japan and England, lower income and educational attainment were significantly associated with a higher risk of being edentulous. Education-based SII in Japan and England were 9.9% and 26.7%, respectively, and RII were 2.5 and 4.8, respectively. Income-based SII in Japan and England were 9.2% and 14.4%, respectively, and RII were 2.1 and 1.9, respectively. Social inequalities in edentulous individuals exist in both these high-income countries, but Japan, with wider coverage for dental care, had lower levels of inequality than England.