title: Repair of dimethacrylate-based composite restorations by a silorane-based composite: a one-year randomized clinical trial.
abstract: OBJECTIVE
  To investigate clinical performance of a low-shrinkage silorane-based composite resin when used for repairing conventional dimethacrylate-based composite restorations.
  
  
  BACKGROUND
  Despite the continued development of resin-based materials, polymerization shrinkage and shrinkage stress still require improvement. A silorane-based monomer system was recently made available for dental restorations. This report refers to the use of this material for making repairs and evaluates the clinical performance of this alternative treatment.
  
  
  METHODS
  One operator repaired the defective dimethacrylate-based composite resin restorations that were randomly assigned to one of two treatment groups: control (n=50) repair with Adper SE Plus (3M/ESPE) and Filtek P60 Posterior Restorative (3M/ESPE), and test (n=50) repair with P90 System Adhesive Self-Etch Primer and Bond (3M/ESPE) and Filtek P90 Low Shrink Posterior Restorative (3M/ESPE). After one week, restorations were finished and polished. Two calibrated examiners (Kw≥0.78) evaluated all repaired restorations, blindly and independently, at baseline and one year. The parameters examined were marginal adaptation, anatomic form, surface roughness, marginal discoloration, postoperative sensitivity, and secondary caries. The restorations were classified as Alpha, Bravo, or Charlie, according to modified US Public Health Service criteria. Mann-Whitney and Wilcoxon tests were used to compare the groups.
  
  
  RESULTS
  Of the 100 restorations repaired in this study, 93 were reexamined at baseline. Dropout from baseline to one-year recall was 11%. No statistically significant differences were found between the materials for all clinical criteria, at baseline or at one-year recall (p>0.05). No statistically significant differences were registered (p>0.05) for each material when compared for all clinical criteria at baseline and at one-year recall.
  
  
  CONCLUSIONS
  The hypothesis tested in this randomized controlled clinical trial was accepted. After the one-year evaluations, the silorane-based composite exhibited a similar performance compared with dimethacrylate-based composite when used to make repairs.
authors.affiliation: Federal University of Minas Gerais, School of Dentistry, Belo Horizonte, Minas Gerais, Brazil. danielavelloso@yahoo.com.br
authors.forename: D A V
authors.initials: DA
authors.lastname: Popoff
authors.forename: T T A
authors.initials: TT
authors.lastname: Santa Rosa
authors.forename: R C
authors.initials: RC
authors.lastname: Ferreira
authors.forename: C S
authors.initials: CS
authors.lastname: Magalhães
authors.forename: A N
authors.initials: AN
authors.lastname: Moreira
authors.forename: I A
authors.initials: IA
authors.lastname: Mjör
mesh_terms: D000293:Adolescent; D000328:Adult; D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods; D003731:Dental Caries / Q000145:classification; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing / Q000379:methods; D058250:Dental Restoration Repair / Q000379:methods*; D003807:Dentin Sensitivity / Q000145:classification; D005500:Follow-Up Studies; D006801:Humans; D008689:Methacrylates / Q000737:chemistry*; D008875:Middle Aged; D058105:Polymerization; D011446:Prospective Studies; D012008:Recurrence; D062047:Silorane Resins / Q000737:chemistry*; D013499:Surface Properties; D055815:Young Adult
chemical_list: D003188:Composite Resins; D003764:Dental Materials; C438835:Filtek P60 Composite Resin; D008689:Methacrylates; D062047:Silorane Resins; C544925:filtek P90