title: Tensile bond strengths of composites to a gold-palladium alloy after thermal cycling.
abstract: BACKGROUND
  Many different materials and methods have been used to fabricate or repair veneer facings with composites, but only a few of these have been studied.
  
  
  OBJECTIVE
  This study compared the tensile bond strengths of composites to a gold-palladium alloy with the use of several surface treatment methods.
  
  
  METHODS
  Forty alloy specimens were cast in Eclipse (52% gold and 37.5% palladium) in the form of truncated cones. These specimens were divided equally into 4 groups. In group I, the bonding surfaces of the metal cones were treated with Silicoater MD. Truncated cones of Dentacolor composite were bonded to the metal surfaces and light-polymerized. In group II, the bonding surfaces of the metal cones were air-particle abraded with 50 microm aluminum oxide and coated with C&B Metabond. Truncated cones of Epic-TMPT composite were bonded to the metal surfaces and light-polymerized. In group III, the bonding surfaces of the metal cones were air-particle abraded with CoJet-Sand. Truncated cones of Pertac-Hybrid composite were bonded to the metal surfaces and light-polymerized. In group IV, the bonding surfaces of the metal cones were air-particle abraded with CoJet-Sand. Truncated cones of Visio-Gem were bonded to the metal surfaces and light-polymerized. After 24 hours of water immersion at 37 degrees C and 1000 thermal cycles in water at 5 degrees C and 55 degrees C, tensile forces were applied to all specimens with a universal testing machine. Analysis of variance was applied to the data (P<.05), and differences among means were determined with a Tukey-Kramer interval of 5.4 MPa.
  
  
  RESULTS
  Tensile bond strengths in MPa were as follows: Dentacolor, 14 +/- 5; Epic-TMPT, 12 +/- 4; Pertac-Hybrid, 13 +/- 5; and Visio-Gem, 18 +/- 4. The tensile bond strength of Visio-Gem was significantly higher than that of Epic-TMPT, but no differences were found among Dentacolor, Pertac-Hybrid, and Epic-TMPT (P<.05).
  
  
  CONCLUSIONS
  Within the limitations of this study, all 4 bonding systems tested produced high bond strengths between composites and a gold-palladium alloy after thermal cycling.
authors.affiliation: Department of Prosthodontics, University of Texas-Houston Dental Branch, Houston, Texas 77030, USA. jchang@mail.db.uth.tmc.edu
authors.forename: Jeffrey Chai
authors.initials: JC
authors.lastname: Chang
authors.forename: Sheila H
authors.initials: SH
authors.lastname: Koh
authors.forename: John M
authors.initials: JM
authors.lastname: Powers
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Duong
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000388:Air; D000537:Aluminum Oxide / Q000737:chemistry; D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D001896:Boron Compounds / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D006047:Gold Alloys / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008768:Methylmethacrylates / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D001896:Boron Compounds; D003188:Composite Resins; C097956:Epic TMPT; D006047:Gold Alloys; D008689:Methacrylates; D008768:Methylmethacrylates; C079764:Pertac hybrid; D019279:Resin Cements; D012821:Silanes; D014867:Water; C046981:ESPE Visio-Gem; C017492:methacryloxypropyltrimethoxysilane; D017438:Bisphenol A-Glycidyl Methacrylate; D010165:Palladium; D012822:Silicon Dioxide; C049495:Super-bond; C057365:Dentacolor; D000537:Aluminum Oxide