Plaque and Salivary Fluoride Levels in Preschoolers Following Applications of Silver Diamine Fluoride, Sodium Fluoride Varnish, and Their Combination: A Randomized Clinical Trial

Background The amount of fluoride maintained in the oral cavity aids in the remineralization process. Hypothesis/Aim To evaluate and compare plaque and salivary fluoride levels following applications of silver diamine fluoride (SDF), sodium fluoride varnish (NaFV), or both. Design Sixty preschoolers randomly received 38% SDF, 5% NaFV, or both (SDF + NaFV). Plaque and saliva were collected at baseline; 5, 30, and 60 min; and 24 and 48 h post‐application. Fluoride levels in plaque and saliva were evaluated and statistically compared ( p < 0.05). Results Salivary fluoride levels peaked 5 min post‐application in all groups and recovered to baseline within 1 to 24 h. Plaque fluoride levels peaked between 5 and 60 min, then returned to baseline within 1 to 24 h. The SDF group had significantly lower plaque and salivary fluoride levels than the other groups. There were no differences in plaque or salivary fluoride levels between NaFV and SDF + NaFV groups; however, the SDF + NaFV group had the longest salivary fluoride retention. Conclusions The application of SDF in combination with NaFV (highest fluoride exposure) resulted in higher fluoride levels in plaque and saliva of preschoolers. Since these levels returned to baseline in less than 24 h, further studies are required to establish the implications for caries arrest and prevention.