Distribution of developmental defects of enamel on ten tooth surfaces in children aged 12 years living in areas receiving different water fluoride levels in Sri Lanka and England.

The prevalence of enamel defects on ten tooth surfaces per subject was recorded in 1990/91 in 12-year-old children living in areas which received drinking water containing either 0.1, 0.5 or 1.0 ppm F, in Sri Lanka and in England. In some communities, children of high and low socioeconomic groups were included. The teeth included were: 46, 14, 13, 12, 11, 21, 22, 23, 24 and 36; buccal surfaces only were examined. One examiner examined all the children under natural light using the modified DDE index (Clarkson and O'Mullane, 1989). Teeth were not especially cleaned or dried. A 10 per cent re-examination of subjects indicated that examiner reproducibility was good. Data were presented for 547 subjects (168 in Sri Lanka and 379 in England). While the maxillary central incisors were affected most often in England and in the 0.1 ppm F area in Sri Lanka, this was not the case in the 0.5 and 1.0 ppm F areas in Sri Lanka where prevalence was highest in premolar and canine teeth. Demarcated and diffuse opacities predominated in the 1.0 ppm F areas in both countries, while hypoplastic lesions were prevalent in Sri Lanka in the 0.1 and 0.5 ppm F areas, especially in maxillary incisor teeth. Nearly half the lesions extended to more than one-third of the tooth surface in the 1.0 ppm F areas. The findings indicate that maxillary canine and premolar teeth are affected much more in high fluoride areas in Sri Lanka and it is suggested that this may be due to their later development relative to incisors and first molars.