title: Fracture toughness of resin-based luting cements.
abstract: BACKGROUND
  The introduction of resin-modified glass ionomer cements has expanded the choices of luting cements available to the clinician; however, few independent studies are available on the fracture toughness of the currently available resin-modified glass ionomer luting agents compared with the composite cements.
  
  
  OBJECTIVE
  This investigation evaluated the relative fracture toughness (K(IC)) of 3 composite luting cements (Panavia 21, Enforce, and C&B Metabond), 3 resin-modified glass ionomer luting cements (Advance, Vitremer Luting, and Fuji Duet), and a conventional glass ionomer luting cement (Ketac-Cem) at 24-hour and 7-day storage times.
  
  
  METHODS
  K(IC) was determined by preparing minicompact test specimens (n = 8) with introduced precracks. Specimens were stored in distilled water at 37 degrees C + 2 degrees C until testing. Testing was performed on an Instron testing machine at a displacement rate of 0.5 mm/min.
  
  
  RESULTS
  ANOVA (P <.001) and REGW Multiple Range Test (P <.05) demonstrated significant differences among several of the cements tested. The mean fracture toughness values of C&B Metabond at 24 hours and Enforce at both 24 hours and 7 days were significantly greater than use any of the other cements tested.
  
  
  CONCLUSIONS
  The resin-modified glass ionomer cements exhibited improved fracture toughness when compared with the conventional glass ionomer; however, they were still inferior to Enforce and C&B Metabond composite cements.
authors.affiliation: College of Dentistry, The Ohio State University, Columbus, Ohio, USA. knobloch.3@osu.edu
authors.forename: L A
authors.initials: LA
authors.lastname: Knobloch
authors.forename: R E
authors.initials: RE
authors.lastname: Kerby
authors.forename: R
authors.initials: R
authors.lastname: Seghi
authors.forename: J S
authors.initials: JS
authors.lastname: Berlin
authors.forename: J S
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000704:Analysis of Variance; D001896:Boron Compounds; D020770:Compomers / Q000737:chemistry; D003188:Composite Resins; D001840:Dental Bonding; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry; D006244:Hardness; D008277:Magnesium Oxide; D008422:Materials Testing / Q000379:methods; D008689:Methacrylates; D008768:Methylmethacrylates; D010710:Phosphates; D011076:Polycarboxylate Cement; D019279:Resin Cements / Q000737:chemistry; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D013997:Time Factors; D019415:Torque; D015034:Zinc Oxide
chemical_list: C094366:Advance cement; D001896:Boron Compounds; D020770:Compomers; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C103503:EnForce-Sure Cure; C113301:FujiPlus; D005899:Glass Ionomer Cements; D008689:Methacrylates; D008768:Methylmethacrylates; C093719:Panavia TPN-S; D010710:Phosphates; D011076:Polycarboxylate Cement; D019279:Resin Cements; C084550:Vitremer; D008277:Magnesium Oxide; C040235:Ketac-cem; C049495:Super-bond; D015034:Zinc Oxide