Effect of school water fluoridation on dental caries: results in Seagrove, NC, after eight years.

In 1968 at Seagrove, NC, fluoride was added to the water supply of a rural school (grades 1 through 12) at a level of 6.3 ppm, seven times the optimum level recommended for community water fluoridation in the area. Findings after eight years showed that children in grades 1 through 8 had approximately 40% fewer DMF surfaces than did their counterparts on the baseline. A comparison of these findings with those of another school fluoridation study, in which a level of 4.5 times the optimum concentration had been tested, showed only a slight advantage to the children at Seagrove. However, the full potential of school water fluoridation at seven times the optimum level cannot be determined until children in all grades will have been exposed since entering the first grade.