Fluoride concentrations of silver diamine fluoride solutions for dental use

Abstract

Objectives: To determine the short-term stability of free fluoride ion concentrations and acidity (pH values) of three commercially available silver diamine fluoride (SDF) solutions over time. Methods: Three SDF products for caries control were studied: Cariestop-12%, Cariestop-30% and Saforide-38%. Their expected fluoride ion concentrations were 14,200 ppm, 35,400 ppm and 44,800 ppm, respectively. The free fluoride ion concentrations were determined with an ion-selective electrode. The acidity was determined with a pH electrode. The measurements were taken when the bottles were newly opened and also after 7 days and after 28 days of storage at 4oC. Five bottles of each product from the same lot number were measured.

Results: The mean free fluoride ion concentrations of the freshly opened bottles were 12,525±450 ppm, 13,200±2,060 ppm and 55,800±2,536 ppm, respectively. The mean pH values were 9.4±0.1, 10.4±0.1 and 10.2±0.2, respectively. There were no statistically significant (ANOVA, p>0.05) changes in the free fluoride ion concentrations or in the acidity in any of the 3 studied products after 7 or 28 days.

Conclusions: All of the SDF solutions tested were alkaline. The free fluoride ion concentrations of two commerically available high concentration SDF solution products were considerably different from those expected. The fluoride ion concentrations and acidity of all three products demonstrated a short-term stability over 28 days