title: Microleakage of Class V Methacrylate and Silorane-based Composites and Nano-ionomer Restorations in Fluorosed Teeth.
abstract: BACKGROUND
  Enamel and dentin marginal sealing ability of the new adhesive materials could play an important role in successful restoration on fluorosed teeth.
  
  
  OBJECTIVE
  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.
  
  
  METHODS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Biomaterial Research Center, Dept. of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran;
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Shafiei
authors.affiliation: Postgraduate Student, Dept. of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran;
authors.forename: Mohadese
authors.initials: M
authors.lastname: Abouheydari
keywords: Fluorosed Teeth; Methacrylate Composite; Microleakage; Nano-ionomer; Silorane Composite