Analysis of factors associated with tooth loss in older adults from 1995 to 2015: a population-based cross-sectional survey in Guangdong, China

The aim of this study was to detect trends and related factors in the functional dentition (FD) in 65- to 74-year-olds in Guangdong, China, while also assessing trends in education and income inequality factors.

Three large-scale cross-sectional National Oral Health Surveys (NOHS), specifically NOHS II in 1995, NOHS III in 2005, and NOHS IV in 2015, were included. Post hoc stratification was weighted for 1038 participants aged 65 to 74years. Retaining teeth ≥ 20 teeth and retaining < 20 teeth was defined as functional dentition (FD) and nonfunctional dentition (NFD), respectively. Logistic regression models were established to assess related factors. Slope index of inequality (SII) and relative index of inequality (RII) were used to analyze inequality.

From NOHS II to IV, the FD proportion increased from 42.8 to 71.9%. Years of NOH, with caries, with periodontal pocket, high educational level, high income level, female, and those who had dental visits were associated with FD preservation. The education-related SII decreased from 0.44 to 0.20, and the income-related SII increased from 0.13 to 0.16.

The FD proportion among 65- to 74-year-olds improved from 1995 to 2015. Years of NOHS, with caries, with periodontal pocket, high education level, and high income level were associated with higher FD proportion. Female and those who had dental visits were associated lower FD proportion. Social inequalities in FD persisted, especially economic-related inequalities. Public health policy support and respective interventions should be applied to increase FD retention.