Effect of a stable 30 per cent stannous fluoride solution on recurrent caries around amalgam restorations

Abstract

This was a study to evaluate the effectiveness of a stable 30 per cent stannous fluoride solution on recurrent caries around the margins of amalgam restorations. Two hundred ninety deciduous and permanent teeth were restored in 34 children, ages six to nine years. Cavity preparations were treated with either stable 30 per cent stannous fluoride solution or a placebo solution (double blind technique) prior to the placement of amalgam restorations. A comprehensive coded system was used to record the description and position of conditions associated with recurrent caries after a one-year period. Children receiving the stannous fluoride treatment experienced a 58.9 per cent reduction in recurrent caries when compared to the control children. The children receiving the stannous fluoride treatment showed a 60.7 and 46.7 per cent reduction in recurrent carious lesions in permanent and deciduous teeth, respectively, when compared to the control children. The reduction in recurrent caries was attributed to the anticariogenic effect of the stannous fluoride treatment. Conditions associated with recurrent caries were mainly inadequate extension in fissures and grooves, overextension of the cavity preparation, marginal fractures of enamel and amalgam, marginal excess, and deterioration of the amalgam margin. Recurrent caries around the margins of restorations appeared to depend on (1) the caries susceptibility of the adjacent tooth structure,(2) the extension of the cavity preparation, and (3) the condition of the amalgam-enamel margin.