A total of 164 schoolchildren, aged 11–15 years with high DMF scores was divided into 4 groups. Subjects of the CXF group brushed their teeth after school lunch and rinsed their mouths with a solution containing 0.05% chlorhexidine gluconate + 0.044% NaF in succinic acid/NaOH buffer, pH 5.9. The F group had 0.044% NaF in the buffer. The PI group used a placebo solution and the C group served as the basic control. Respective nonabrasive toothpaste preparations were used in the evenings and twice a day during weekends and the holidays. After 2 years, the mean DMFS increments in the C, Pl, F and CXF groups were 6.3, 5.1, 4.3 and 2.9, respectively. The percentage of subjects with bleeding vestibular gingival units examined in different groups had changed from initial to final value as follows: C, 40–63; PI, 50–49; F, 71–47 and CXF, 63–14.