title: Shear bond strengths of a ceramic system to alternative metal alloys.
abstract: BACKGROUND
  The success of metal-ceramic restorations is influenced by the compatibility between base metal alloys and porcelains. Although porcelain manufacturers recommend their own metal systems as the most compatible for fabricating metal-ceramic prostheses, a number of alloys have been used. Purpose This study evaluated the shear bond strength between a porcelain system and 4 alternative alloys.
  
  
  METHODS
  Two Ni-Cr alloys: 4 ALL and Wiron 99, and 2 Co-Cr alloys: IPS d.SIGN 20 and Argeloy NP were selected for this study. The porcelain (IPS d.Sign porcelain system) portion of the cylindrical metal-ceramic specimens was 4 mm thick and 4 mm high; the metal portion was machined to 4x4 mm, with a base that was 5 mm thick and 1 mm high. Forty-four specimens were prepared (n=11). Ten specimens from each group were subjected to a shear load on a universal testing machine using a 1 mm/min crosshead speed. One specimen from each group was observed with a scanning electron microscope. Stress at failure (MPa) was determined. The data were analyzed with a 1-way analysis of variance (alpha=.05).
  
  
  RESULTS
  The groups, all including IPS d.Sign porcelain, presented the following mean bond strengths (+/-SD) in MPa: 4 ALL, 54.0+/-20.0; Wiron, 63.0+/-13.5; IPS d.SIGN 20, 71.7+/-19.2; Argeloy NP, 55.2+/-13.5. No significant differences were found among the shear bond strength values for the metal-ceramic specimens tested.
  
  
  CONCLUSIONS
  None of the base metal alloys studied demonstrated superior bond strength to the porcelain tested.
authors.affiliation: San José dos Campos Dental School, Paulista State University, São José dos Campos, São Paulo, Brazil. marquesdemelo@bol.com.br
authors.forename: Renata Marques
authors.initials: RM
authors.lastname: de Melo
authors.forename: Alessandro Caldas
authors.initials: AC
authors.lastname: Travassos
authors.forename: Maximiliano Piero
authors.initials: MP
authors.lastname: Neisser
mesh_terms: D000704:Analysis of Variance; D002858:Chromium Alloys; D001840:Dental Bonding / Q000379:methods*; D003776:Dental Porcelain; D008422:Materials Testing / Q000379:methods; D016876:Metal Ceramic Alloys; D008855:Microscopy, Electron, Scanning; D033081:Shear Strength
chemical_list: D002858:Chromium Alloys; D016876:Metal Ceramic Alloys; D003776:Dental Porcelain