Effect of silver and fluoride ions on enamel demineralization: a quantitative study using micro-computed tomography

Background: This study aimed to investigate the effect of silver and fluoride ions on demineralization of enamel. Methods: The coronal parts of 40 extracted sound premolars were prepared into tooth blocks. An unvarnished occlusal surface window (OW) and a flat buccal/lingual surface window (FW) were created for each tooth by covering all other surfaces with an acid‐resistant varnish. These blocks were randomly allocated into four groups of 10 blocks each and immersed in respective solutions for 5 minutes: Group 1 – 2.36 M silver fluoride; Group 2 – 2.36 M potassium fluoride; Group 3 – 2.36 M silver nitrate; and Group 4 – deionized water. After 7‐day immersion in a buffered demineralization solution at pH 4.4, micro‐CT scans were taken. Results: Mean lesion depth in the FW area for tooth blocks in AgF, KF, AgNO₃ and control groups were 0 μm, 3.3 ± 10.3 μm, 156.3 ± 30.8 μm, and 173.6 ± 48.6 μm, respectively (p < 0.001). The difference in mean lesion depth between the AgNO₃ and control groups was not statistically significant (p > 0.05). Similar OW and FW lesions were observed in tooth blocks in the AgNO₃ and control groups. Conclusions: Topical application of a 2.36 M fluoride solution can inhibit demineralization of enamel while topical application of silver ions has little effect.