Trends in dental caries rates in 12- and 13-year-old schoolchildren from Florianópolis (Brazil) between 1971 and 2005.

Objective: To estimate dental caries prevalence and severity among all 12- and 13-year-old schoolchildren enrolled in a public school in 2005 and to establish comparisons with the results of studies previously conducted in the same school in 1971, 1997 and 2002.

Methods: A cross-sectional study involving 190 children was carried out. A single calibrated examiner collected the clinical data according to the World Health Organization (1997) criteria.

Results: The response rate was 90.0%. Between 1971 and 2005, the observed reduction in caries prevalence was 58.2%, whereas the mean DMFT Index declined from 9.2 to 0.8, which corresponds to a reduction of 91.3%. The significant caries index (SiC) reduced from 3.4 (CI 95% 3.0-3.8) in 2002 to 2.2 (CI 95% 1.8-2.5) in 2005.

Conclusions: This study indicates an actual decline in dental caries prevalence and severity among the schoolchildren during the studied period, even though different diagnostic criteria were used.