RESUMO
<p><b>OBJECTIVE</b>This longitudinal study aimed to investigate the caries status of primary and permanent teeth among 6-year-old children in Sichuan Province from 2010 to 2012.</p><p><b>METHODS</b>A sample that comprised 652 6-year-old children from six different elementary schools (three represented the urban areas, and the other three represented the rural areas) were examined according to a baseline, with follow-up examinations at 1, 2, and 3 years. Eruption and caries experience were re- corded using World Health Organization criteria.</p><p><b>RESULTS</b>The prevalence rates of primary tooth caries of 6-year-old children in Sichuan Province for 3 years were 74.23% (484/652), 75.61% (493/652), and 81.90% (534/652). The filling rate of the primary teeth was 5.87% (145/2,471) in 2012, with significant differences (P < 0.01) between the urban areas [10.84% (133/ 1,227)] and rural areas [0.96% (12/1,244)]. The total pit and fissure rate of the first molar was 14.11% (92/652) in 2012, with significant differences between the two areas (P < 0.01) [rural: 0.66% (2/303); urban: 25.79% (90/349)].</p><p><b>CONCLUSION</b>The pre- valence of caries in the primary and permanent teeth of 6-year-old children was high. An increasing prevalence tendency was observed as the age increased. The prevalence of first molar caries indicated that prevention and control of dental caries should be performed as early as possible.</p>