A previous report has shown the anticariogenic effects of combined topical fluoride application in school dental health programs (Isozaki, 1984). The aim of the present study was to evaluate the cariostatic effects on each tooth surface in school children given topical fluoride treatments by using Cohort analysis.
The subjects of this study were 827 school children (437 boys and 390 girls) who were in the 1-6 grade in 1975. Topical fluoride application was given once a year using an acidulated phosphate fluoride solution (0.9% F-, pH 3.6), and fluoride mouthrinsing was practiced 5 times a week after every school lunch with a phosphoric acid-acidfied sodium fluoride solution (0.05% F- pH 5.0). Cohort observations on each tooth surface were carried out for anticariogenic effects from 1976 to 1980 according to the school grade levels of the subjects.
Cohort analysis on the DMFS of each tooth type showed a statistically significant anticariogenic effect in the groups which started these programs from the lower grade levels. The results were as follows: The proximal- and lingal-surface of central and lateral incisor, and occlusal surface of first and second premolar of maxilla, and occlusal surface of second premolar of mandibula showed a decrease in the DMFS rate. Especially, the group which started from the first grade showed high anticariogenic effect on the occlusal surface of the maxillar and mandibular first molar.
These results study indicate that combined topical fluoride treatments have a high anticariogenic effect on each tooth surface.
Regarding the measures of caries prevention applied to school dental health program, it is suggested that combined topical fluoride treatments are usefull, and that it is necessary to start from the lower school grade and to carry out this program continuously through the primary school years.
