An in vitro study of silver and fluoride ions on remineralization of demineralized enamel and dentine

Background The purpose of this study was to compare the effect of silver fluoride, silver nitrate and potassium fluoride on remineralization of demineralized enamel and dentine in vitro. Methods Forty premolars were cut into cuboidal blocks. Acid-resistant varnish was painted onto each block to cover all surfaces, except two windows, one in enamel and one in dentine. The tooth blocks were placed in demineralizing solution for 96hours. They were then randomly divided into four groups of 10 blocks each and immersed in solutions of AgF, AgNO3, KF or water for 3minutes. Afterwards, they were immersed in a remineralizing solution for 108hours. Micro CT scanning was conducted before and after remineralization. Results The increase in linear attentuation coefficient (LAC) for the enamel lesions after remineralization was 1.08/cm, 0.95/cm, 0.86/cm and 0.60/cm in the AgF, AgNO3, KF and control groups, respectively (ANOVA, p<0.001; AgF, AgNO3, KF > control; AgF > KF). The increase in LAC for the dentine lesions was 1.01/cm, 0.92/cm, 0.88/cm and 0.53/cm, respectively (ANOVA, p<0.001; AgF, AgNO3, KF > control). Conclusions Topical application of silver or fluoride ions can increase the mineral density of demineralized enamel and dentine lesions during remineralization. The synergistic effect of silver and fluoride ions is relatively small.