Page 1 of study

BY the time that Brantford, Ontario, began to fluoridate its water supply in 1945 a great deal of information had been obtained from various parts of the word concerning the effect of naturally fluoridated water on dental caries. This information showed that the incidence of tooth decay is greatly reduced in populations consuming from birth naturally fluoridated water at a level of about one part per million. No ill effects at this level were observed. We therefore wished to determine whether the incidence of tooth decay could be reduced among children consuming fluoride-deficient water by the controlled adjustment of the fluoride content of that water supply to about one part per million.

The Brantford water supply has been continuously fluoridated since 1945. In 1946 the Department of National Health and Welfare was invited to make a comparison study of the dental effects of water fluoridation by periodically examining the teeth of Brantford children, the teeth of children living in a city having a naturally fluoridated water supply (Stratford) and also the teeth of children of a city having a negligible amount of fluoride in its water supply (Sarnia). The Dental Health Division of the Department of National Health and Welfare conducted this study with assistance from the Research and Statistics Division of the Department, and with the co-operation of the Ontario Department of Health and the local departments of health of Brant County, of Stratford and of Lambton (Sarnia).

Selection of Children

All native 16- and 17-year old children continuously resident in each city were included in the study (Table 1). Continuous residence encompasses absences, since birth, of six weeks or less. Thus the study compares (1) Brantford children who used mechanically fluoridated water continuously since birth, with (2) Sarnia children who used fluoride-deficient water continuously since birth, and (3) Stratford children who used continuously since birth water naturally fluoridated from underground deposits of fluoride. For individual children, residence eligibility was determined from information supplied by the parents. Vocational, and all separate and public secondary schools of each city were included.

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Published simultaneously in the Journal of the Canadian Dental Association and in the Canadian Journal of Public Health by arrangement between the authors and editors.

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H.K. Brown, Lecturer, Faculty of Dentistry, University of British Columbia, Vancouver… formerly Chief, Dental Health Division, Department of National Health and Welfare, Ottawa, Ontario.

M. Poplove, Research Consultant, Dental Health Division, Department of National Health and Welfare, Ottawa, Ontario.

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*Original abstract online at https://www.jstor.org/stable/41984741

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