ABSTRACT
Objective To analyze the operation of water improvement projects in drinking water-borne fluorosis areas of Qinghai Province and the trend of dental fluorosis in children aged 8 to 12 years, and to evaluate the effects of prevention and control measures comprehensively, so as to provide basis for improving prevention and control strategies. Methods In 2009 - 2017, according to the "Qinghai Drinking Water Endemic Fluorosis Surveillance Program", four project counties of Huangyuan, Minhe, Hualong and Guide were selected in Qinghai Province. Three villages in each project county were selected according to their mild, moderate and severe conditions, and monitored the operation of water improvement projects, water fluoride content and dental fluorosis among children aged 8 to 12-year-old in each diseased village. Results In 2009-2017, the normal operation rate of water improvement projects increased from 2/8 to 7/8; the batch operation rate of the projects decreased from 5/8 to 1/8; the number of abandoned projects decreased from 1 to 0; the number of people covered by qualified water fluoride increased from 9962 to 80760 people; there was no significant difference in water fluoride content between different years (F = 0.758, P > 0.05). The total detection rate of children's dental fluorosis was 33.01％(1812/5489) from 2009 to 2017, the index of dental fluorosis was 0.65, and the epidemic intensity was slightly prevalent;the detection rate of children's dental fluorosis was 30.02％(951/3168) in villages with normal operation of water improvement projects and qualified water fluoride content, the index of dental fluorosis was 0.58, and the epidemic intensity was marginal;the detection rate of children's dental fluorosis was 32.72％(583/1782) in villages with abnormal operation of water improvement projects or excessive fluoride, the index of dental fluorosis was 0.66, and the epidemic intensity was slight; the detection rate of children's dental fluorosis in villages without changing the water was 51.58％ (278/539), and the index of dental fluorosis was 1.04, belonging to the moderate epidemic intensity; the detection rate of children's dental fluorosis in villages without changing the water was significantly higher than that in villages with normal operation of water improvement projects and qualified water fluoride content (χ2 = 102.30, P < 0.01). Conclusions The water improvement project in drinking water-borne fluorosis areas is running well and the operation rate is increasing year by year. The detection rate of dental fluorosis in children aged 8-12 years old in villages with normal operation of water improvement projects and qualified water fluoride content was significantly lower than that in villages without changing the water. The monitoring of fluorosis and the maintenance of water-renovation projects should be strengthened, and the problem of drinking water for residents in villages without changing the water should be resolved as soon as possible.
ABSTRACT
Objective To investigate the incidence of dental fluorosis and pit caries in school-age children from binhai new area of Tianjin, and to discuss the relationship between dental fluorosis and pit caries, providing the guidance for the prevention and treatment of them. Methods Referring to WHO’s“Oral Health Surveys Basic Methods”(Fourth Edition) and protocols of the third national oral epidemiology investigation, 3 778 children aged 7 to 9 year-old with similar levels of education were investigated for their dental fluorosis and fissure caries using the cross sectional survey method. Results The data showed that the incidence of dental fluorosis was less than 10%in the samples, and the community fluorosis index (CFI) was 0.075. The caries prevalence rate and mean decayed missing filled tooth (DMFT) of first permanent molars were 15.57%and 0.46 in male students, and those were 17.41%and 0.58 in female students. There were no significant differences in the caries prevalence rate and DMFT of first molar between male and female children (χ2=2.345, P>0.05). There were statistically significant differences in the caries rate and DMFT between different age groups (χ2=172.576, P<0.05), and both increased with age. Conclusion After years of defluoridation project in Tianjin, the detection rate and index of dental fluorosis in children have showed a downward trend. The caries prevalence rate may be related to the eruption rate of the first permanent molar.