Comparative analysis on child dental fluorosis under different circumstances of water-improvement and defluoridation in Shandong Province

Objective To investigate the present prevalence of endemic fluorosis in Shandong Province. Methods 13 regions were randomized as the investigative sites. The content of fluoride in drinking water was determined by F-ion selective electrode and dental fluorosis of children diagnosed by Dean method. Results The investigation covered 337 fluorosis villages of 31 counties belonging to 13 regions. The fluoride content exceeded 1.00 mg/L in 54.41% of the villages,the total rate of dental fluorosis of children aged 8 ~ 12 years was 41.39%,the index of dental fluorosis was 0.95 and the rate of dental damage was 9.10%. In the villages that had not improved water,69.77% had a fluoride content over 1.00 mg/L(max:6.62 mg/L),the rate of dental fluorosis was 41.84%,the index of dental fluorosis was 0.95 and the rate of dental damage was 9.06%. Among the villages where water-improvement and defluoridation projects worked normally,the villages with fluoride content over 1.00 mg/L accounted for 37.04%(max:5.57 mg/L),the rate of dental fluorosis was 33.29%,the index of dental fluorosis was 0.73 and the rate of dental damage was 5.98%. Among the villages where water-improvement and defluoridation projects had been abandoned,villages with fluoride content over 1.00 mg/L accounted for 72.84%(max:8.32 mg/L),the rate of dental fluorosis was 57.18%,the index of dental fluorosis was 1.35 and the rate of dental damage was 15.02%. Conclusions Endemic fluorosis is still quite serious in Shandong Province. Therefore, preventing and controlling measures for endemic fluorosis must be carried out and surveillance of endemic fluorosis must be strengthened.