Amount of Fluoride Delivered via a Topical Application of 38% Silver Diamine Fluoride Solution and 5% Sodium Fluoride Varnish

Objectives: The objectives of this study were to compare the amount of fluoride delivered via a topical application of 38% silver diamine fluoride (SDF) solution and 5% sodium fluoride (NaF) varnish, as well as to determine the amount of 38% SDF solution delivered using various micro-applicators.
Methods: The weights of 38% SDF (Saforide) and 5% NaF (Duraphat) applied to the occlusal surface of an extracted human upper first premolar with a regular-size (2.50-mm tip diameter) micro-applicator for 60 s were measured using an electronic-analytical balance. Afterward, the weight of 38% SDF applied to a premolar using the micro-applicators of five common brands (Premium Plus, 3M, Dentsply, Elevate Oral Care and SDI) were studied. The tip diameter of each micro-applicator was measured under a microscope. The weights of the delivered fluoride and silver were also calculated.
Results: The mean weights of the fluoride delivered via the SDF solution and NaF varnish were 0.25±0.07mg and 0.49±0.08mg, respectively (p<0.001). In addition, the tip diameters of the micro-applicators ranged from 1.89±0.03 mm to 2.76±0.02 mm. The mean weights of the fluoride delivered per application of 38% SDF using different applicators ranged from 0.13±0.06 mg to 0.30±0.09 mg, whereas the mean weights of the silver ranged from 0.76±0.32 mg to 1.68±0.50 mg. The weights of the delivered 38% SDF solution varied with the brand and with the tip diameters of the dental micro-applicators (p<0.001).
Conclusions: The fluoride of the 38% SDF solution delivered topically was significantly less than that of 5% NaF varnish. Moreover, the amount of SDF solution delivered depends on the brand and size of the micro-applicators.