Dental Health Survey after Communal Water Fluoridation was Discontinued in Chung-Hsing New Village, Taiwan

• Published in: JOURNAL OF DENTAL HEALTH Vol. 43; no. 2; pp. 177 - 185
• Main Authors: GUNJISHIMA, Yuka, TSUTSUI, Akihito, SAKAI, Osamu, KOBAYASHI, Seigo, YAGI, Minoru, HORII, Kin-ichi, CHOU, Ming-jer
• Format: Journal Article
• Language: English
• Published: Japanese Society for Oral Health 1993
• Subjects: Dental caries; Dental fluorosis; Water fluoridation
• ISSN: 0023-2831; 2189-7379
• DOI: 10.5834/jdh.43.177

In 1972 water fluoridation was begun in Chung-Hsing New Village, Taiwan and it was discontinued in 1986. At the first stage, fluoride concentration was 0.6ppm, and was changed to 1.0ppm in 1978. Chung-Hsing New Village is located about 20km south-east of Taichung city and the mean temperature is 73.4 degrees Fahrenheit. In July 1991, to survey the dental effects in the 5 years after the water fluoridation discontinued, we conducted a dental survey in Chung-Hsing New Village and in Tsao-Tun as a control area. Two dentists examined dental caries with the criteria of WHO and one dentist examined dental fluorosis with Dean's criteria. The subjects in Chung-Hsing New Village were 93 schoolchildren aged 10-12 who had been drinking fluoridated water from birth to 5-7 years of age and 80 schoolchildren aged 14 or 15 who had been drinking from birth to 9 or 10years of age. In Tsao-Tun, the control group was 99 schoolchildren aged 10-12 and 78 schoolchildren aged 14 or 15. In the 10-12-year old schoolchildren, the mean DMFT was 1.19 (SE=0.17) in Chung-Hsing New Village and 2.55 (0.26) in Tsao-Tun. The difference was 53.3% (p<0.001). In 14 or 15-year-old schoolchildren, the DMFT was 2.38 (0.35) and 3.39 (0.34), respectively. The difference was 29.8% (p<0.05). The mean DMFS for each tooth type in Chung-Hsing New Vlliage was smaller than in Tsao-Tun. We found more effectiveness in the 1st molars and the incisors than in the other teeth. High caries preventive effects were produced by fluoride exposure not only in the calcification period, but also in the post-eruptive maturation period. In both areas, we could not find moderate or severe dental fluorosis. The prevalence rate of dental fluorosis was low and the difference between Chung-Hsing New Village and Tsao-Tun was not significant. CFI varied from 0.05 to 0.15. The present study proved that the water fluoridation produced caries preventive effects and the favorable effects remained for 5 years after discontinuation of the projects. In addition, there was no public health problem of dental fluorosis.