title: Tensile fatigue of two composite cements bonding three base metal alloys to bovine enamel.
abstract: Tensile fatigue endurance limits were determined for three base metals (Ni-Cr, Ni-Cr-Be, and Co-Cr) bonded to bovine enamel using two composite cements: a Bis-GMA/phosphate ester composite cement which relies on a sand-blasted metal surface, and a Bis-GMA composite luting cement which relies on electrolytically etched metal surfaces. Samples were tested to failure or to 10(6) cycles at 5 hz in Ringer's solution at 37 degrees C, and endurance limits were determined using a two-point test strategy. SEM evaluation was performed on fractured samples to determine failure mode. Statistical analysis of the results showed no difference between cements when using Ni-Cr-Be; however when using Co-Cr, the Bis-GMA/phosphate ester cement produced greater values than the Bis-GMA cement that relied on electrolytical etching. The opposite result occurred when a Ni-Cr alloy was tested with both cements. Evaluation of the results for each cement with the three different alloys showed statistical significant differences. SEM fracture analysis revealed a mixed failure pattern with apparent adhesive fracture from both the composite-enamel and composite-metal interfaces and cohesive failure throughout the cement.
authors.affiliation: University of Mississippi, School of Dentistry, Jackson.
authors.forename: J G
authors.initials: JG
authors.lastname: Fitchie
authors.forename: L D
authors.initials: LD
authors.lastname: Zardiackas
authors.forename: D A
authors.initials: DA
authors.lastname: Givan
authors.forename: L
authors.initials: L
authors.lastname: Anderson
authors.forename: W F
authors.initials: WF
authors.lastname: Caughman
mesh_terms: D000818:Animals; D001608:Beryllium / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate; D002417:Cattle; D002858:Chromium Alloys / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements; D003799:Dental Stress Analysis; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009532:Nickel / Q000737:chemistry; D010710:Phosphates; D019279:Resin Cements; D013718:Tensile Strength
chemical_list: D002858:Chromium Alloys; D003738:Dental Cements; D010710:Phosphates; D019279:Resin Cements; C061503:Comspan; D003035:Cobalt; D017438:Bisphenol A-Glycidyl Methacrylate; D009532:Nickel; C052304:Panavia EX; D001608:Beryllium