title: Shear bond strength of self-adhesive resin cements to base metal alloy.
abstract: BACKGROUND
  Many self-adhesive cements have been introduced in the past few years, with little or no data regarding their clinical performance. This study investigated the shear bond strength of some recently introduced self-adhesive resin cements.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the shear bond strength of self-adhesive and conventional resin-based cements to a base metal alloy.
  
  
  METHODS
  Four groups (10-12 each) that comprised 3 self-adhesive cements (SmartCem2; RelyX Unicem; seT SDI) and a conventional resin-based cement (RelyX ARC) were tested. Cylindrical cement specimens (diameter, 3 mm; height, 3 mm) were applied to nickel-free base metal alloy (Sheradent) disks with a diameter of 12 mm, and the surface was treated with airborne-particle abrasion of 50 μm aluminum oxide. The metal disks were fixed in brass molds specifically designed for the shear bond test device. Test specimens were incubated at 37°C for 24 hours and then the shear bond was tested with a Zwick Roll testing machine at a 0.8 mm/min cross-head speed. In addition, bond failures were investigated and categorized as adhesive, cohesive, or mixed. Shear bond strengths were calculated by dividing the maximum debonding force over the cross-sectional area of each specimen. One-way ANOVA and the Tukey (honestly significant difference) post hoc test were used to test statistical significant differences among the groups (α=.05).
  
  
  RESULTS
  Statistical analysis showed significant differences among different resin cements (F=14.34, P<.001). The highest mean shear bond strength was observed for SmartCem2 (14.18 MPa), and the lowest was reported for seT (3.52 MPa). The observed failure mode in all the materials was adhesive in nature, which occurred at the resin-metal interface.
  
  
  CONCLUSIONS
  The early bond strength of self-adhesive resin cements varied significantly among the tested materials. SmartCem2 showed the highest bond strength, which was 4 times the strength observed for seT SDI.
authors.affiliation: Assistant Professor and Consultant, Department of Conservative Dentistry, Faculty of Dentistry, The University of Jordan, Amman, Jordan. Electronic address: s.hattar@ju.edu.jo.
authors.forename: Susan
authors.initials: S
authors.lastname: Hattar
authors.affiliation: Maxillofacial Prosthetist, Queen Medical Centre, Nottingham University Hospital Trust; School of Dentistry, University of Manchester, Manchester, UK; and Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Jordan.
authors.forename: Muhanad
authors.initials: M
authors.lastname: Hatamleh
authors.affiliation: Professor and First-Consultant, Department of Conservative Dentistry, Faculty of Dentistry, The University of Jordan, Amman, Jordan.
authors.forename: Ameen
authors.initials: A
authors.lastname: Khraisat
authors.affiliation: Assistant Professor and Consultant, Department of Conservative Dentistry, Faculty of Dentistry, The University of Jordan, Amman, Jordan.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Al-Rabab'ah
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000268:Adhesiveness; D000537:Aluminum Oxide / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002858:Chromium Alloys / Q000737:chemistry*; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
chemical_list: D000180:Acrylic Resins; D002858:Chromium Alloys; D008689:Methacrylates; D011109:Polymethacrylic Acids; D011140:Polyurethanes; C483701:Rely X Unicem; C462240:RelyX ARC; D019279:Resin Cements; C029824:urethane dimethacrylate luting resin; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C031172:4-META resin; D000537:Aluminum Oxide