title: Shear bond strength between Ni-Cr alloy bonded to a ceramic substrate.
abstract: BACKGROUND
  The aim of this study was to evaluate the shear bond strength between a Ni-Cr alloy and a ceramic system submitted or not to thermocycling.
  
  
  METHODS
  Forty-eight cylinder blocks of Ni-Cr with 3.0 mm diameter by 4.0 mm hight and 48 disc-shaped specimens (7.0 mm in diameter by 2.0 mm thick) composed of ceramic were prepared. The Ni-Cr cylinder blocks were randomised in two groups of 24 specimens each. One group was submitted to air-particle abrasion (sandblasting) with 50 μm Al(2)O(3) (0.4-0.7 MPa) during 20 s, and the other group was submitted to mechanical retentions with carbide burrs. Each group was subdivided into other two groups (n = 12), submitted or not to thermocycling (500 cycles, 5-55°C). The cylinder blocks were bonded to the disc-shaped ceramic specimens under 10 N of load. The shear bond strengths (MPa) were measured using a universal testing machine at a cross head speed of 0.5 mm/min and 200 kgf of load. The data were submitted to statistical analysis (anova and Tukey's test).
  
  
  RESULTS
  The air-particle abrasion group exhibited significantly higher shear bond strength when compared to drilled group (p < 0.05).
  
  
  CONCLUSIONS
  Thermocycling decreased significantly the bond strengths for all groups tested.
authors.affiliation: Department of Dental Materials and Prosthodontics, Faculty of Dentistry of Ribeirão Preto, University of São Paulo, Monte Alegre, Ribeirão Preto, SP, Brazil.
authors.forename: Cássio
authors.initials: C
authors.lastname: do Nascimento
authors.forename: Paola Kirsten
authors.initials: PK
authors.lastname: Miani
authors.forename: Osvaldo Luiz
authors.initials: OL
authors.lastname: Bezzon
authors.forename: Mariane
authors.initials: M
authors.lastname: Gonçalves
authors.forename: Rubens Ferreira
authors.initials: RF
authors.lastname: de Albuquerque Junior
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D000538:Aluminum Silicates / Q000737:chemistry; D002858:Chromium Alloys / Q000737:chemistry*; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry; D003775:Dental Polishing / Q000379:methods; D003776:Dental Porcelain / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D018130:Diamond / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008768:Methylmethacrylates / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature
chemical_list: D000538:Aluminum Silicates; D002858:Chromium Alloys; D003764:Dental Materials; D008768:Methylmethacrylates; D017680:Potassium Compounds; C528569:Rely-X; D019279:Resin Cements; D003776:Dental Porcelain; C016447:feldspar; C034578:Duralay; D018130:Diamond; D000537:Aluminum Oxide