Trends in dental caries rates over 45 years (1971-2016) among schoolchildren in Florianópolis, southern Brazil.

OBJECTIVE: The present study aimed to estimate the prevalence and severity of dental caries in schoolchildren from Florianópolis, southern Brazil, in 2016, as well as to compare these findings with data obtained from six previous studies carried out in the same school since 1971.

METHODS: A cross-sectional study was conducted with 133 schoolchildren, 12 and 13 years of age. Clinical data were collected by three previously calibrated examiners, according to the 2013 World Health Organization diagnostic criteria, in order to estimate the mean count of decayed, missing and filled teeth/surfaces (DMFT/DMFS indexes) and the Significant Caries Index (SiC).

RESULTS: The study response rate was 87.2% (n = 116), and the prevalence of dental caries decreased from 98.0% (95% CI: 96.0-100.0) in 1971 to 39.6% (95% CI 30.7-49.2) in 2016. The mean DMFT index fell from 9.2 in 1971 to 0.9 in 2016, while the DMFS index ranged from 2.0 (95% CI: 1.2-2.8) in 2009 to 1.5 (95% CI: 1.0-1.9) in 2016. The SiC index, which was 3.4 (95% CI: 3.0-3.8) in 2002, reached 2.5 (95% CI: 2.0-2.9) in 2016.

CONCLUSION: Over the 45 years of monitoring, a significant decline in rates of dental caries has been observed. However, the SiC index suggests that dental caries lesions are unequally distributed in the study sample, with one-third of the schoolchildren showing a significantly higher mean DMFT score compared with the entire sample.