microleakage of class v methacrylate and silorane-based composites and nano-ionomer restorations in fluorosed teeth

statement of the problem: enamel and dentin marginal sealing ability of the new adhesive materials could play an important role in successful restoration on fluorosed teeth. purpose: the aim of this in vitro study was to evaluate the marginal microleakage of low-shrinkage silorane-based composite, nano-ionomer, and methacrylate-based composite through self-etching approach or with enamel acid etching. materials and method: seventy-two extracted human molars with moderate fluorosed (according to thylstrup and fejerskov index, tfi= 4-6) were randomly divided into six groups (n=12). class v cavities were prepared on the buccal surface at the cementoenamel junction and restored with clearfil se bond/clearfil ap-x (methacrylate composite), silorane adhesive system/filtek p90 , and nano primer/nano-ionomer according to the manufacturer’s instructions (self-etching approach) or with additional selective enamel acid etching before primer application for each adhesive. after water storage and thermocycling, microleakages of the samples were assessed using dye-penetration technique at the enamel and dentin margins. data were analyzed using non-parametric tests (α = 0.05).   results: there was a significant difference among the six groups at the enamel margin ( p = 0.001), but not at the dentin margin ( p = 0.7). for all the three adhesive materials, additional enamel etching resulted in significantly reduced microleakage at the enamel margin ( p < 0.05). conclusion: methacrylate- and silorane-based composites and nano-ionomer revealed a similar and good performance in terms of dentin marginal sealing, but not at the enamel margin. the additional selective enamel etching might improve enamel sealing for the three materials.