Relationship between the amount of fluoride in drinking water and DMFT

Regarding the high rate of dental caries and its known consequences and the necessary to have disease etiologic studies and in order to determine any relation between fluoride amounts of drinkable water, we performed the research for DMFT amount in rural of Behshahr city in 2006. We performed our research by historical cohort on 165 persons in case group in different areas with lower amount of fluoride than 0.4 ppm, and 164 persons in control group in different areas with natural fluoride between 0.6-1.2 ppm that, the persons of both groups were similar to the point of the height, age, gender, position of father, residing period in place, literacy level and wideness of family and our sampling method based up on the goal. Their DMFT condition was assessed according to determined standard and the role of low fluoride in drinking water with exposing more than 5 teeth and chi-square statistic. The amount of DMFT in case zones was equal to 11/7 +-7/9 and 8/4+-6/6 in control group (P<0/0005). The people of case zones had 83% of DMFT above 5 and those in control group 65% (p<0/0005). R.R of low fluoride in water has been 1.3 times more than control, with exposing DMFT of over 5 in case people. The risk relating to the high dental caries for subjects with low fluoride of drinking water has been 18% as well (R.R=1/3). It seems that the low amount of fluoride of drinkable water may increase the chance of DMFT we may recommend any experimental researches in order to determine any effects of adding fluoride to water in order to prevent from DMFT.