Effect of Professional Flossing with Chlorhexidine Gel on Approximal Caries in 12- to 15-Year-Old Schoolchildren

Abstract

The aim of the investigation was to evaluate the effect of chlorhexidine gel treatment on caries development of approximal tooth surfaces and on salivary counts of Streptococcus mutants. 220 12-year-old schoolchildren, divided into three groups, participated: chlorhexidine gel group (n = 72), placebo gel group (n = 77), and control group (n =71). The study was carried out double blind with respect to the two gel groups. Group 1 was treated 4 times/year with 1% chlorhexidine gel and group 2 with a placebo gel. Approximately 1 ml of gel was applied interdentally by means of a flat dental floss. The control group did not receive any gel treatment of flossing. Number of Streptococcus mutans in the saliva was estimated on five occasions during the study with the spatula method. After 3 years, the mean approximal caries increment, expressed as new DFS, was 2.50 in the chlorhexidine gel group and 4.30 in the placebo gel group (p < 0.005). The corresponding figure in the control group was 5.25 (p < 0.001 when compared to group 1). 44% of the children in the chlorhexidine gel group and 32% in the placebo gel group did not develop any new approximal caries lesion during the 3-year observation period compared to 18% in the control group (group 1-3 p < 0.001; group 2-3 p < 0.05). The number of new approximal fillings (FS) was 0.24 in the chlorhexidene gel group, 0.75 in the placebo gel group and 0.82 in the control group (group 1-3 p < 0.01; group 2-3 p < 0.05). There was no statistically significant difference between the groups with respect to numbers of S. mutans in saliva. However, there were more inidividuals with low numbers of S. mutans in the chlorhexidine gel group at the final examination compared to the baseline level (p < 0.05).