title: The effect of LED curing mode on microleakage of Class V cavity restored by silorane-based composite.
abstract: OBJECTIVE
  This in vitro study evaluated the effect of soft-start curing mode by LED unit on the marginal microleakage of silorane composite restoration.
  
  
  METHODS
  Class V cavities were prepared on the buccal surfaces of 80 extracted molars at the cementoenamel junction and randomly divided into eight groups. In groups 1-4, four adhesive/composite combinations (silorane/silorane, silorane/Z250, Adper Single Bond/Z250, Clearfil SE Bond/Clearfil AP-X) were applied and the composites were cured under standard mode at 1500 mW/cm(2) for 20 s. In the other four groups, after applying the same adhesive/composite combinations, the composites were cured at 550 mW/cm(2) for 10 s followed at 1500 mW/cm(2) for 15 s. After 24 h of water storage and thermocycling, the specimens were placed in 1% methylene blue solution. The dye penetration was assessed under a stereomicroscope. The data were analysed using non-parametric tests.
  
  
  RESULTS
  There were no significant differences among four groups for two curing modes at the occlusal and gingival margins (p > 0.05). The soft-start curing had a positive effect on the gingival marginal sealing of group 1 (p < 0.05), but not for the other three groups (p > 0.05).
  
  
  CONCLUSIONS
  The beneficial effect of relatively high soft-start curing on marginal sealing of Class V restoration depends on a combination of the adhesive and composite types, having a positive effect on silorane adhesive/silorane-based composite at the gingival margin.
authors.affiliation: Department of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Shafiei
authors.forename: Sahar
authors.initials: S
authors.lastname: Akbarian
mesh_terms: D000269:Adhesives; D006801:Humans; D008027:Light; D008963:Molar; D012117:Resins, Synthetic / Q000737:chemistry*; D062047:Silorane Resins / Q000737:chemistry*
chemical_list: D000269:Adhesives; D012117:Resins, Synthetic; D062047:Silorane Resins