Arresting simulated dentine caries with adjunctive application of silver nitrate solution and sodium fluoride varnish: an invitro study

PurposeThe aim of this invitro study was to assess the ability of silver nitrate solution, followed by sodium fluoride varnish, to arrest caries. MethodsDentine slices were prepared and demineralised. Each slice was cut into three specimens for three groups (SF, SDF and W). Specimens of the SF group received topical application of 25% silver nitrate solution followed by 5% sodium fluoride varnish. The SDF group received topical application of 38% silver diamine fluoride solution (positive control). Specimens of the W group received deionised water (negative control). All specimens were subjected to pH cycling for 8days. Dentine surface morphology, crystal characteristics, carious lesion depth and collagen matrix degradation were evaluated by scanning electron microscopy, X-ray diffraction, X-ray microtomography and spectrophotometry with a hydroxyproline assay. ResultsScanning electron microscopy showed that dentine collagen was exposed in group W, but not in groups SF and SDF, while clusters of granular spherical grains were formed in groups SF and SDF. The mean lesion depths (standard deviation) of groups SF, SDF and W were 128 +/- 19, 135 +/- 24 and 258 +/- 53m, respectively (SF, SDF