title: Surface conditioning of a composite used for inlay/onlay restorations: effect on muTBS to resin cement.
abstract: OBJECTIVE
  To assess the effect of the composite surface conditioning on the microtensile bond strength of a resin cement to a composite used for inlay/onlay restorations.
  
  
  METHODS
  Forty-two blocks (6 x 6 x 4 mm) of a microfilled composite (Vita VMLC) were produced and divided into 3 groups (N = 14) by composite surface conditioning methods: Gr1--etching with 37% phosphoric acid, washing, drying, silanization; Gr2--air abrasion with 50-lm Al203 particles, silanization; Gr3--chairside tribochemical silica coating (CoJet System), silanization. Single-Bond (one-step adhesive) was applied on the conditioned surfaces and the two resin blocks treated with the same method were cemented using RelyX ARC (dual-curing resin cement). The specimens were stored for 7 days in water at 37 degrees C and then sectioned to produce nontrimmed beam samples, which were submitted to microtensile bond strength testing (muTBS). For statistical analysis (one-way ANOVA and Tukey's test, alpha = 0.05), the means of the beam samples from each luted specimen were calculated (n = 7).
  
  
  RESULTS
  muTBS values (MPa) of Gr2 (62.0 +/- 3.9a) and Gr3 (60.5 +/- 7.9a) were statistically similar to each other and higher than Gr1 (38.2 +/- 8.9b). The analysis of the fractured surfaces revealed that all failures occurred at the adhesive zone.
  
  
  CONCLUSIONS
  Conditioning methods with 50-lm Al203 or tribochemical silica coating allowed bonding between resin and composite that was statistically similar and stronger than conditioning with acid etching.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Federal University of Santa Maria, Brazil. lfvalandro@hotmail.com
authors.forename: Luiz Felipe
authors.initials: LF
authors.lastname: Valandro
authors.forename: Fernanda
authors.initials: F
authors.lastname: Pelogia
authors.forename: Graziela
authors.initials: G
authors.lastname: Galhano
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Bottino
authors.forename: Andre
authors.initials: A
authors.lastname: Mallmann
mesh_terms: D000134:Acid Etching, Dental; D000268:Adhesiveness; D000537:Aluminum Oxide / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D045662:Dental Etching; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D007284:Inlays; D008422:Materials Testing; D010756:Phosphoric Acids / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D014867:Water / Q000737:chemistry
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; C448319:ESPE bonding system; D010756:Phosphoric Acids; D011109:Polymethacrylic Acids; C462240:RelyX ARC; D019279:Resin Cements; D012821:Silanes; C115612:single bond; D014867:Water; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D012822:Silicon Dioxide; C030242:phosphoric acid; D000537:Aluminum Oxide