[The optimal concentration of drinking water in eastern Guangdong].
ABSTRACT The objectives were to explore the optimal concentration of drinking water in Eastern Guangdong and to provide information for the health administrative department to set up the criteria for fluoride concentration.
Totally 1237 9-17 and 35-44 years old residents in Eastern Guangdong who drinking water containing 0.1-2.5 mg/L fluoride were recruited to investigate the occurrences of dental caries and dental fluorosis. Their background information and perceived appearances of teeth were also recorded.
The major factor influencing dental fluorosis was fluoride concentration in drinking water. Dental caries decreased when the fluoride concentration increased but dental fluorosis also increased at the same time. It was showed by calculation that the Dental Fluorosis Index would be 0.4 and 0.6 when the fluoride concentration was 0.57 mg/L and 0.7 mg/L respectively. The acceptation to the severity of dental fluorosis among the study subjects was in accordance with the Dean's criteria.
It suggests that the optimal fluoride concentration in Eastern Guangdong is 0.57 mg/L and should not exceed the upper limit of 0.7 mg/L.