Changes in dental caries prevalence in 12-year-old students in the State of Mexico after 9 years of salt fluoridation.

The purpose of this study was to describe the dental caries experience in 12-year-old students in the State of Mexico and to detect changes after 9 years of salt fluoridation (1988-1997). The 1987 WHO dental caries criteria were used in both surveys. The population studied encompassed 2,275 12-year-old students in 1988, and 1,138 in 1997. The proportion of 'caries-free' children was 10. 3% in the first survey and 27.7% in the second one. The mean DMFT index was 4.39 (SD 2.9) in 1988 and 2.47 (SD 2.4) in 1997, the confidence interval of the differences between DMFT means was [95% CI 1.73, 2.11]; the caries reduction detected was 43.7%. The Unmet Restorative Index was 82.3% in 1988 and 72.8% in 1997. The results of the present study indicate that the oral health status of State of Mexico students has improved during the last decade; however, there is still a need for further caries reduction and an increment in access to dental treatment.