[Caries, fluorosis and salt fluoridation in the city of Szeged]

Salt fluoridation is effective at inhibiting caries, but fluorosis prevalence data are different. The purpose was to undertake a blind caries and tooth mottling study of 14-yrs-olds from S. E. Hungary who did (Test) or did not (Control) live, until 1985, in a 350 pp F-/kg salt fluoridated area during their early years of life. In Szeged, blind clinical and anterior tooth-mottling, radiographic and photographic recording of 49 previously salt-fluoridated and 59 non-salt-fluoridated subjects were undertaken by one examiner. In Glasgow, four dental and two lay staff scored the projected 35 mm colour transparencies of each pupil's teeth (13-23), for tooth mottling. Mean DMFS scores were 9.18 (SD = 10.72) and 4.51 (SD = 6.4) for Test and Control users respectively (p < 0.01). Clinically three Test children had fluorosis of 10 teeth, with 8 teeth in two Controls. In a sole Test case was "fluorosis" photographic unanimity obtained, and non-unanimous "possible fluorosis" was recorded by two-four 'jurors' for only three other Test and two Control subjects. No evidence was found that significant fluorosis resulted in subjects exposed previously to 350 ppm F-/kg salt early in life, but no caries benefit was demonstrated after the 11.5-yr salt fluoridation gap. These data emphasize (a) the superiority of substained community-delivered fluoridation, and (b) the need to maintain constant fluoride delivery to tooth surfaces, and certainly well beyond 10 years of age.