Changes in oral health inequalities in adults in Chile

The adult population in Chile has a high prevalence of dental caries and non-functional dentition. Fifteen years after the Health Reform, aimed to reduce health inequalities, it is necessary to analyse changes in social inequalities in oral health in Chilean adults.

A secondary analysis of data from 2003 and 2016-2017 National Health Surveys (NHS) in Chile was performed on seven oral health outcomes in adults: prevalence of untreated caries, prevalence of severe untreated caries, number of teeth with untreated caries, prevalence of functional dentition, prevalence of edentulism, number of remaining natural teeth and utilization of dental services. Inequalities were measured with the Slope Index of Inequality (SII) and the Relative Index of Inequality (RII) by education level.

A decrease of caries inequalities measured with SII was observed from 2003 to 2016-17 NHS but an increase of remaining teeth inequalities was measured. The SII of the remaining teeth increased from 6.6 [95% CI = 5.0, 8.2] in 2003 to 8.8 [95% CI = 7.3, 10.3] in 2016-17. The SII of functional dentition by education increased from 29.0 [95% CI = 22.0, 36.0] in 2003 to 38.8 [95% CI = 32.6, 45.0]) in 2016-17. The utilization of dental services ≤1 year was the only outcome that showed a decrease in absolute and relative inequality, the SII was 33.9 [95% CI = 23.3, 45.6] in 2003 and 26.2 [95% CI = 16.6, 35.8] in 2016-17 and the RII decreased from 2.5 [95% CI = 1.7, 3.3] in 2003 to RII = 1.8 [95% CI = 1.4, 2.3] in 2016-17.

The increase of tooth loss inequalities in contrast to the decrease of inequalities in dental services utilization show the need to re-evaluate the current dental programmes for adults in Chile. This may include establishing a stronger oral health promotion strategy and greater dental treatment coverage focusing on avoiding tooth extractions in vulnerable social groups.