Introduction: Tooth decay is still a highly prevalent disease in populations. Because of this, epidemiological studies are carried out frequently and allow the monitoring of the experience of the disease. Objective: To estimate the prevalence of dental caries of 5 and 12-years-old schoolchildren in the cities of Florianópolis, Santa Catarina, and Porto Velho, Rondônia, as well as to search hypotheses of association with social/economic determinants and access to dental services. Material and methods: Secondary data were used from the Brazilian Oral Health Survey of 2010, as follows: household income by city and dmft/DMFT index for ages by city and region of Brazil. Results: It was observed in the city of Florianópolis a 5-years-old dmft of 1.56, and 12-years-old DMFT of 0.55. In Porto Velho the means were 2.89 and 4.15 to the respective age. It was found that in Porto Velho 89.5% of surveyed had family income up to R$2,500.00, while in Florianópolis 81.9% had R$501.00 to R$9,500.00. Conclusion: The city of Florianópolis had the best caries indices and socioeconomic conditions, suggesting an association between these variables, in detriment to the regions in the opposite situation.

Tooth decay is still a highly prevalent disease in populations. Because of this, epidemiological studies are carried out frequently and allow the monitoring of the experience of the disease. Objective: To estimate the prevalence of dental caries of 5 and 12-years-old schoolchildren in the cities of Florianópolis, Santa Catarina, and Porto Velho, Rondônia, as well as to search hypotheses of association with social/economic determinants and access to dental services. Material and methods: Secondary data were used from the Brazilian Oral Health Survey of 2010, as follows: household income by city and dmft/DMFT index for ages by city and region of Brazil. Results: It was observed in the city of Florianópolis a 5-years-old dmft of 1.56, and 12-years-old DMFT of 0.55. In Porto Velho the means were 2.89 and 4.15 to the respective age. It was found that in Porto Velho 89.5% of surveyed had family income up to R$2,500.00, while in Florianópolis 81.9% had R$501.00 to R$9,500.00. Conclusion: The city of Florianópolis had the best caries indices and socioeconomic conditions, suggesting an association between these variables, in detriment to the regions in the opposite situation.