title: The effect of recasting on bond strength between porcelain and base-metal alloys.
abstract: OBJECTIVE
  Long-term success of metal ceramic restorations depends on metal ceramic bond strength. The purpose of this study was to determine whether recasting of base-metal alloys has any effect on metal ceramic bond strength.
  
  
  METHODS
  Super Cast and Verabond base-metal alloys were used to cast 260 wax patterns. The alloy specimens were equally divided into five groups and cast as: group A 0.0%, B 25%, C 50%, D 75%, and E 100% once-cast alloy. Each group was divided into two subgroups: the first group was cast with Super Cast and the second with Verabond. In each subgroup half of the cast alloys were veneered with Vita VMK 68 and the others with Ceramco 3.
  
  
  RESULTS
  Recasting decreased bond strength (p < 0.006) when used for 50% once-cast alloy. Group E with 100% new Super Cast alloy veneered with Vita VMK 68 porcelain had the highest bond strength (30.75 ± 9.58 MPa), and group B including 25% new and 75% recast Super Cast alloy veneered with the same porcelain had the lowest bond strength (21.72 ± 5.19 MPa).
  
  
  CONCLUSIONS
  By adding over 50% once-cast alloy in base-metal alloys, metal-ceramic bond strength decreases significantly.
authors.affiliation: Department of Prosthodontics, Dental Material Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran. madania@mums.ac.ir
authors.forename: Azam S
authors.initials: AS
authors.lastname: Madani
authors.forename: Shahin Rezaii
authors.initials: SR
authors.lastname: Rokni
authors.forename: Abolghasem
authors.initials: A
authors.lastname: Mohammadi
authors.forename: Mehran
authors.initials: M
authors.lastname: Bahrami
mesh_terms: D002858:Chromium Alloys / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry; D001840:Dental Bonding; D003734:Dental Casting Investment / Q000737:chemistry; D003735:Dental Casting Technique; D003776:Dental Porcelain / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D003801:Dental Veneers; D006801:Humans; D008422:Materials Testing; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D018583:Pliability; D013314:Stress, Mechanical
chemical_list: D002858:Chromium Alloys; D003722:Dental Alloys; D003734:Dental Casting Investment; D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; C058233:Ceramco; C047040:Vita VMK 68