Dental influences caused by changes in fluorid concentration of drinking water

本研究的目的是评估自1988年以来一直供应非氟化水的日本一个自然氟化城镇（ltayanagi）饮用水中氟浓度变化的影响。1998年对该镇6至14岁的儿童进行了牙科检查。此外，还检查了他们的居住史和水中氟化物浓度。因为即使在1988年以后，含氟化物的地下水仍然用于日常生活。天然水的氟浓度在0.25 - 1.52 ppm之间，而供水的氟浓度为0.05 ppm。根据问卷调查，17%的儿童仍然使用地下水作为饮用水。6 ~ 11岁儿童平均DMFT指数与1993年全国调查数据基本一致。1975 - 1976年儿童龋病指数接近全国数据的一半，近年来发现该地区龋病患病率呈上升趋势。儿童氟斑牙患病率相应下降。因此，结论是水溶氟化物对预防龋齿的好处在受试地区已经丧失。考虑到龋病在不久的将来可能会增加，需要一些有效的牙齿健康计划。

The aim of this study was to assess the influence of changes in fluoride concentrations of drinking water in a naturally fluoridated town (ltayanagi) in Japan where non-fluoridated water has supplied since 1988. Dental examination was carried out in 1998 for children aged 6 -14 years old in the town. In addition, their residential history and water fluoride concentrations were examined. Since underground water containing fluoride were still used for daily living even after 1988. The F concentrations of the natural water ranged from 0.25 to 1.52 ppm, whereas supplied water had 0.05 ppm F.According to the questionair, 17% children still used underground water for drinking. Mean DMFT index of children aged 6 - 11 years old were nearly equal to the data from the national survey in 1993. Since the DMFT index of children was nearly half of the national data in 1975 - 1976, it was found that the caries prevalence in the area increased recently. Correspondingly, prevalence rate of dental fluorosis decreased among children. Hence, it was concluded that the benefits for caries prevention by water born fluoride has lost in the subjected area. Considering possible increase of caries prevalence in the near future, some effective dental health programs should be required.