Trends in socioeconomic disparities in oral health in Brazil and Sweden

Objectives: To describe the dynamics of trends in socioeconomic disparities in oral health in Brazil and Sweden among adults, to assess whether trends follow expected patterns according to the inverse equity hypothesis.

Methods: In Sweden, we obtained nationally representative data for the years 1968, 1974, 1981, 1991 and 2000, and in Brazil, for 16 state capitals in 1986 and in 2002. Trends in the prevalence of 'edentulism' and of 'teeth in good conditions' were described in two groups aged 35-44 with lower and higher economic standards, respectively.

Results: There was an annual decline in disparities in 'edentulism' of 0.4 percentage points (pp) (95% CI = 0.2-0.7) in Brazil and 0.7pp (95% CI = 0.5-0.9) in Sweden, as a result of improvements in both income groups. Concerning 'teeth in good conditions', in Brazil, there was improvement only in the higher income group and absolute disparities have increased (0.5pp annually), while in Sweden, there was a nonsignificant decrease (0.3pp annually) with improvements in both groups. Since 1991 in Sweden and in 2002 in Brazil, our measures of socioeconomic disparities in 'edentulism' were not statistically significant. Trends did not differ by sex or dental visit.

Conclusions: Despite improvements in both income groups and a decrease in disparities in 'edentulism', the poorer group in Brazil has seen no improvement in 'teeth in good conditions' and disparities have increased. It appears that Brazil and Sweden reflect different stages of trend for 'teeth in good conditions' and the same stages for 'edentulism', represented by the inverse equity hypothesis.