Effect of fluoride varnishes on oral bacteria of preschool children with cavitated and non-cavitated carious lesions: randomized clinical trial

We compare the effect of calcium and phosphate-containing sodium fluoride (NaF) varnishes to conventional NaF varnish on S. mutans and L. fermentum counts. 3–4 years old children were grouped according to their caries status (n = 45 each): caries-free, with non-cavitated and with cavitated lesions. Each group was randomly subdivided (n = 15 each) into: Group 1- 5% NaF, Group 2- 5% NaF with tricalcium phosphate, Group 3- 5% NaF with casein phosphopeptide- amorphous calcium phosphate. Biofilm and saliva were collected to quantify microorganisms at baseline (T1) and 24-months (T2). Differences between groups were compared using Kruskal–Wallis test, followed by Dunn-Bonferroni post-test, at 0.0167 α-level. Significant difference was found for percentage of children with detectable biofilm L. fermentum ( p = 0.013) at T1 and salivary S. mutans ( p = 0.011) at T2. Percentage of children increased from T1 to T2 in Group 2 with salivary S. mutans ( p = 0.007), salivary L. fermentum ( p = 0.035), and biofilm L. fermentum ( p = 0.019) and in Group 3 with salivary L. fermentum ( p = 0.035). Bacterial change was not significant in both samples of intervention groups, except increase in salivary S. mutans ( p = 0.038) in Group 3. Both calcium- and phosphate-containing NaF varnishes demonstrated similar antibacterial effect on S. mutans and L. fermentum compared to conventional NaF varnish.