On June 20th, 1955, Brantford completed ten years of experience with mechanically fluoridated water.
Earlier reports (1) have shown that the full decay-preventing effect of the fluoridated water on the permanent dentition of the Brantford children began to show itself in 1951, when the first permanent molars appeared in the mouths of the children born there in 1945. In 1953, after these teeth had been exposed in the mouths of the eight-year-old children for a period of two years out reports showed that they were found to be as decay-resistant as those of the children in the corresponding age group in Stratford, where water fluoridated to the extent of 1.6 parts per million from an underground deposit of fluoride had been in use continuously for thirty-eight years. This was the first clear demonstration that mechanically fluoridated water was as effective as naturally fluoridated water in the prevention of tooth decay. It was further confirmed by the 1954 survey. The 1955 survey, which is reported here, contributes additional data which are presented and analyzed in the succeeding pages
Before the Brantford water supply was fluoridated a great deal of information had been assembled from various parts of the world, which showed beyond any reasonable doubt that water containing 1 to 1.5 parts per million of fluoride, dissolved out from underground deposits, could be consumed safely, and would greatly reduce the incidence of tooth decay, particularly among those consuming it from birth (2). Questions were raised in some quarters as to whether or not the caries inhibiting effect might depend upon other chemical substances with which the fluoride could be associated. There was no evidence from the field of chemistry to suggest this. It appeared to be highly probable that the fluoride itself was entirely responsible for the reduction in tooth decay. It is a common constituent of the earth’s crust, readily available, and not costly. This situation gave rise to hope for a simple inexpensive way to prevent tooth decay, especially among children. As it was well known that such trace quantities as one part per million in a water supply could be safely consumed, it was decided to find out whether or not the raising of the fluoride content of a previously fluoride-deficient water supply to one part per million by the mechanical addition of sodium fluoride would reduce the incidence of tooth decay as effectively as one part per million of fluoride derived by the passage of water through an underground deposit of fluoride.
In 1947 a study was instituted in which the caries prevalence of Brantford children would be compared periodically with that of a city having a naturally fluoridated water supply, and also with that of a city having no fluorides in…
(1) Dental Health Division, Department of National Health and Welfare.
(2) Research and Statistics Division, Department of National Health and Welfard.
*This excerpt online at https://www.jstor.org/stable/41980810