INTRODUCTION: Dental caries is the most prevalent disease of the oral cavity, leding to serious economic and social consequences. Studies on the prevalentce of dental caries should be undertaken periodically for the adequat planning of oral health services and action. This research project sought to discover the prevalence of dental caries in the counties of S. Paulo State, Brazil, measured by means of the DMF-T rate on the 12 year-old bracket from 1990-1995. MATERIAL AND METHOD: Data originally produced by Municipal Health Departments, collected by means of an instrument devised for this purpose, sent to 625 counties in the state, were used. The counties concerned were grouped according to their size and geographical region. RESULTS: The total of 625 counties of S. Paulo State, 237 (37.9%) provided the information requested, and 125 (20.0%) had data on DMF-T corresponding to about 5,000 12 year-old children available examined. The study revealed that the prevalence of dental caries is low in only 4.0% of the counties, and is hight or very hight in approximately 80% of them . The DMF-T index values varied from1.3 to 13.6, and the estimated average for all the counties was 4.8. Further, it was discovered that "large" counties recorded 54.6% of their population classified in the categories of low or moderate prevalence of caries; while in "small" counties 87.8% of the population corresponded to the high or very high caries prevalence range. CONCLUSIONS: This research project has shown that the county services for oral health in S. Paulo State have made little use of the basic resources that epidemiology can provide. This indicates the need for an appropriate professional background for oral health in epidemiology, especially for those who fulfil duties in the coordination of the services.
DMF Index; Dental health services; Epidemiology