A 3-year study among Yugoslavian schoolchildren on caries reduction after topical application of 4% NaF-PO4

The purpose of this study was to test the caries‐inhibiting effect of 4 %NaF in 0.1M H3PO4, pH 4.6 after application once or twice a year. Four hundred and ninety‐seven children, 10–12 years old, with totally repaired teeth, were randomly divided into three groups, which were treated as follows: Group 1: control, Group 2: fluoride topical application once a year, Group 3: fluoride topical application twice a year at 6‐month intervals. The differences among groups were analyzed on the basis of caries increment of teeth and of caries increment of surfaces. The analysis was made for all teeth, for teeth present initially and for teeth erupted during the study. The 3‐year study showed that topical application of NaF‐POj solution causes a significant caries inhibition in children at that age. It can be stated that the caries reduction expressed in DFT as well in DFS for all teeth was higher in Group 3 (about 30%) than in Group 2 (about 20%). This difference was especially marked for newly erupted teeth (34.4 % against 8.3 %).