title: Repair bond strength in aged methacrylate- and silorane-based composites.
abstract: OBJECTIVE
  To evaluate the tensile bond strength at repaired interfaces of aged dental composites, either dimethacrylate- or silorane-based, when subjected to different surface treatments.
  
  
  METHODS
  The composites used were Filtek P60 (methacrylate-based, 3M ESPE) and Filtek P90 (silorane-based, 3M ESPE), of which 50 slabs were stored for 6 months at 37°C. The surface of adhesion was abraded with a 600-grit silicone paper and the slabs repaired with the respective composite, according to the following surface treatment protocols: G1: no treatment; G2: adhesive application; G3: silane + adhesive; G4: sandblasting (Al2O3) + adhesive; G5: sandblasting (Al2O3) + silane + adhesive. After 24-h storage in distilled water at 37°C, tensile bond strength (TBS) was determined in a universal testing machine (Instron 4411) at a crosshead speed of 0.5 mm/min. The original data were submitted to two-way ANOVA and Tukey's test (α = 5%).
  
  
  RESULTS
  The methacrylate-based composite presented a statistically significantly higher repair potential than did the silorane-based resin (p = 0.0002). Of the surface treatments for the silorane-based composite, aluminum-oxide air abrasion and adhesive (18.5 ± 3.3MPa) provided higher bond strength than only adhesive application or the control group without surface treatment. For Filtek P60, the control without treatment presented lower repair strength than all other groups with surface treatments, which were statistically similar to each other. The interaction between the factors resin composite and surface treatment was significant (p = 0.002).
  
  
  CONCLUSIONS
  For aged silorane-based materials, repairs were considered successful after sandblasting (Al2O3) and adhesive application. For methacrylate resin, repair was successful with all surface treatments tested.
authors.forename: Atais
authors.initials: A
authors.lastname: Bacchi
authors.forename: Rafael Leonardo
authors.initials: RL
authors.lastname: Consani
authors.forename: Mario Alexandre
authors.initials: MA
authors.lastname: Sinhoreti
authors.forename: Victor Pinheiro
authors.initials: VP
authors.lastname: Feitosa
authors.forename: Larissa Maria
authors.initials: LM
authors.lastname: Cavalcante
authors.forename: Carmem Silva
authors.initials: CS
authors.lastname: Pfeifer
authors.forename: Luis Felipe
authors.initials: LF
authors.lastname: Schneider
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry; D012828:Silicones / Q000737:chemistry; D062047:Silorane Resins / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003188:Composite Resins; C438835:Filtek P60 Composite Resin; D008689:Methacrylates; D011140:Polyurethanes; D012828:Silicones; D062047:Silorane Resins; C544925:filtek P90; C555513:silorane composite resin; D014867:Water; C029824:urethane dimethacrylate luting resin; C041979:2,2-bis-(4-(2-methacryloxyethoxy)phenyl)propane; D017438:Bisphenol A-Glycidyl Methacrylate; D000537:Aluminum Oxide