Caries prevention with chlorhexidine-thymol varnish in high risk schoolchildren

In a prospective, randomised and blinded cohort study, the acceptance and e ffectiveness of a 3-monthly chlorhexidine-thymol varnish application was as sessed in 8- to 10-yr-old children (n=29) with high caries incidence after brushing with a 1.23% fluoride gel. The children of the control group (n=25 ) brushed with a fluoride gel only. The standardised interview showed good acceptance of the varnish applications in spite of the bitter taste. Caries incidence in one year was 1.2 DMFS (SD 1.5, median 1; 95% confidence inter val 0-1) for the test group and 2.1 DMFS (SD 2.3, median 2; 95% confidence interval 0-3) for the control group. Due to a slightly lower reduction in c aries incidence (42.3%) than in other studies and a higher standard deviati on than in unselected study groups, the power of the present study was not high enough to prove this difference in caries incidence to be statisticall y significant in the Mann-Whitney test (P=0.11). This was also found for th e difference of 0.4 initial lesions. The distribution patterns of caries in cidence for tooth groups (70% in the first permanent molar) and surfaces (5 8% on occlusal surfaces) did not differ between the test and the control gr oup. The reductions of caries incidence which have been found in highly car ies active children of the present study should be evaluated further with a larger study sample.