title: Two-year clinical performance of a low-shrinkage composite in posterior restorations.
abstract: OBJECTIVE
  The aim of this study was to compare the two-year clinical performance of three restorative systems in posterior restorations, which included a low-shrinkage composite and both etch-and-rinse and self-etch adhesive strategies.
  
  
  METHODS
  After signing an informed consent, 25 patients received three Class I (occlusal) or Class II restorations performed with one of three restorative systems: Filtek Silorane Restorative System, Adper Scotchbond 1 XT (a two-step etch-and-rinse adhesive) with Filtek Z250, and Adper Scotchbond SE (a two-step self-etch adhesive) with Filtek Z250. All materials were applied following the manufacturer's instructions. Two blind observers evaluated the restorations at three different moments (baseline; and after one and two years) according to the US Public Health Service modified criteria. Kruskal-Wallis test and Mann-Whitney U-test were used to compare the behavior of the restorative systems, while Friedman and Wilcoxon tests were applied to analyze the intra-system data (p<0.05).
  
  
  RESULTS
  The three restorative systems showed a statistically similar clinical performance at two years. Intra-system comparisons between baseline and two years showed declining marginal adaptation scores in the restorations placed with all systems. In addition, marginal staining and surface roughness scores were lower after two years for the restorations placed with Adper Scotchbond SE + Filtek Z250.
  
  
  CONCLUSIONS
  Although the clinical performance of Filtek Silorane was considered acceptable after two years, no advantage of the silorane-based resin over the methacrylate-based composite was found. Teeth restored with Adper Scotchbond SE showed a tendency for marginal staining, which may compromise the final color of the restorations.
authors.forename: B
authors.initials: B
authors.lastname: Baracco
authors.forename: J
authors.initials: J
authors.lastname: Perdigão
authors.forename: E
authors.initials: E
authors.lastname: Cabrera
authors.forename: L
authors.initials: L
authors.lastname: Ceballos
mesh_terms: D000293:Adolescent; D000328:Adult; D003188:Composite Resins / Q000627:therapeutic use*; D019232:Dental Restoration Failure / Q000706:statistics & numerical data; D003793:Dental Restoration, Permanent / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D019279:Resin Cements / Q000627:therapeutic use; D062047:Silorane Resins / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D003188:Composite Resins; C543062:Filtek LS Low Shrink resin; C444701:Filtek Z250; D019279:Resin Cements; D062047:Silorane Resins; C555513:silorane composite resin; C041330:Scotchbond