PREVALENCE OF DENTAL-CARIES AND DENTAL FLUOROSIS IN AREAS WITH OPTIMAL AND ABOVE-OPTIMAL WATER FLUORIDE CONCENTRATIONS - A 10-YEAR FOLLOW-UP SURVEY

Objectives: This paper presents findings for dental caries and fluoros is from an October 1990 follow-up survey in Illinois and compares resu lts with those obtained from two similar school-based examinations con ducted in 1980 and 1985 within the same communities. Methods: The seve n study sites were grouped into four categories according to the appro ximate relation of their water fluoride concentration to the recommend ed optimal fluoride level for the area. Tests for differences in denta l caries and dental fluorosis across the four wafer fluoride groupings and three examinations were conducted. Results: DMFS scores for child ren who resided in communities with above-optimal wafer fluoride level s did not change significantly from 1980 through 1990. At the optimal wafer fluoride concentration, caries scores did not change substantial ly from 1980 to 1985; however, the mean DMFS score in 1990, 1.9, was s ignificantly lower than caries levels observed during the two previous exams. In the optimally fluoridated area, the proportion of fluorosed tooth surfaces increased significantly from 1980 to 1985, but then de clined by 1990 to the level observed in 1980 for both age groups. Conc lusions: The results suggest that: (1) in the optimally fluoridated co mmunity, the apparent increase in the prevalence of dental fluorosis o bserved from 1980 to 1985 did not continue from 1985 to 1990; and (2) at above-optimal wafer fluoride concentrations, dental fluorosis eithe r remained stable or demonstrated no sustained increase over the decad e.