ABSTRACT
Objective@#To evaluate the dynamic prevalence of dental fluorosis of children and levels of fluoride in drinking water after improvement of water in Xi an City, to provide scientific basis for water fluoridation improvement.@*Methods@#A total of 35 fluorosis endemic villages were selected as fixed monitor sites in 2014-2018, the ways of water improvement were surveyed, water fluorine content were detected and the prevalence of dental fluorosis in children aged 8 to 12 years were examined.@*Results@#Rates of excess fluoride in drinking water from 2014 to 2018 were 22.86%, 14.29%,11.43%, 11.43% and 8.57%, the difference were significant(χ2=16.44, P<0.01).The dental fluorosis detection rates of children aged 8 to 12 years were 20.89%,18.22%,17.46%,18.13% and 16.76% in 2014-2018 which showed a obvious descending trend by year(χ2=10.02, P<0.01). The detection rate of dental fluorosis in children aged 8 and 9 years showed a decreasing trend by year(χ2=6.53, 4.54, P<0.05).The difference of total rate of dental fluorisis,rate of mild cases rate of moderate-to-severe cases were statistically between the villages without qualified water and the villages with normal fluorine water(χ2=179.22, 167.93,10.35, P<0.01). The rate of detection in the villages with the water fluorine exceed standard in 2014-2018 showed a declining trend year by year(χ2=28.50, P<0.01). The detection rate were significant different across water improvement methods(χ2=197.76, P<0.01). Detection rate of dental fluorosis decreased from 2014 to 2018 in the areas with municipal water supply showed a decreasing after year(χ2=12.16, P<0.01).@*Conclusion@#The improvement of municipal water supply shows significant effects on water fluorosis control, the detection rate of water fluoride and children s dental fluorosis in some villages with the other ways of water improvement are still higher than expected, the continuously monitor of fluoride content in water and dental fluorosis in children should be strengthened.