Acidity, fluoride and silver ion concentrations in silver diamine fluoride solutions: a pilot study.

Abstract

There has been renewed interest in the use of silver diamine fluoride (SDF) for the management of carious lesions in high-risk groups. Previous studies have found a difference in clinical efficacy among different concentrations of SDF and discrepancies between ionic concentrations of fluoride (F) and silver (Ag) in SDF preparations. The aim of this study was to measure the free F, Ag ion concentrations and pH of a variety of commercially available SDF preparations. Seven SDF products used globally were evaluated for F and Ag ion concentrations using a calibrated ion-selective electrode and optical emission spectrometry respectively. Acidity was determined with a pH electrode. The 30% SDF solution contained almost half the F concentration and a much higher Ag concentration than expected (16343ppmF and 246000ppmAg). Comparatively, the mean F concentration of the remaining six 38% solutions was 74802ppm (expected mean 44800ppm) ranging from 36457ppm to 120760ppm. The mean Ag concentration was 326000ppm (expected mean 253870ppm) and ranged from 246000ppm to 425451ppm. All solutions were found to be neutral or mildly alkaline in nature (pH 7-10.3). Wide variations between claimed and measured F and Ag ion concentrations exist among the different brands of commercially available SDF products.