title: Micro-shear bond strength of different resin cements to ceramic/glass-polymer CAD-CAM block materials.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effects of hydrofluoric acid treatment on bond strength of resin cements to three different types of ceramic/glass containing CAD-CAM block composite materials.
  
  
  METHODS
  CAD-CAM block materials of polymer infiltrated (Vita Enamic), resin nanoceramic (Lava Ultimate) and nanoceramic (Cerasmart) with a thickness of 1.5mm were randomly divided into two groups according to the surface treatment performed. In Group 1, specimens were wet-ground with silicon carbide abrasive papers up to no. 1000. In Group 2, 9.6% hydrofluoric acid gel was applied to ceramics. Three different resin cements (RelyX, Variolink Esthetic and G-CEM LinkAce) were applied to the tubes in 1.2-mm thick increments and light-cured for 40s using LED light curing unit. Half of the specimens (n=10) were submitted to thermal cycling (5000 cycles, 5-55°C). The strength measurements were accomplished with a universal testing machine (Lloyd Instruments) at a cross-head speed of 0.5mm/min until the failure occurs. Failure modes were examined using a stereomicroscope and scanning electron microscope. The data were analyzed with multivariate analysis of variance (MANOVA) and Tukey's post hoc tests (α=0.05).
  
  
  RESULTS
  There were significant differences between ceramics and resin cements (p<0.001). However, hydrofluoric acid gel treatment had no effect on bond strength values (p=0.073). In addition, thermal cycling significantly decreased bond strength values of resin cements to ceramics (p<0.001).
  
  
  CONCLUSIONS
  Use of appropriate resin cement systems with different ceramic/glass-polymer materials might promote the bonding capacity of these systems.
authors.affiliation: Gazi University, Faculty of Dentistry, Department of Prosthodontics, Ankara, Turkey. Electronic address: isilcekic@gmail.com.
authors.forename: Isil
authors.initials: I
authors.lastname: Cekic-Nagas
authors.affiliation: Gazi University, Faculty of Dentistry, Department of Prosthodontics, Ankara, Turkey.
authors.forename: Gulfem
authors.initials: G
authors.lastname: Ergun
authors.affiliation: Gazi University, Faculty of Dentistry, Department of Prosthodontics, Ankara, Turkey.
authors.forename: Ferhan
authors.initials: F
authors.lastname: Egilmez
authors.affiliation: Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre - TCBC, University of Turku, Turku, Finland; City of Turku, Division of Welfare, Turku, Finland.
authors.forename: Pekka Kalevi
authors.initials: PK
authors.lastname: Vallittu
authors.affiliation: Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre - TCBC, University of Turku, Turku, Finland.
authors.forename: Lippo Veli Juhana
authors.initials: LV
authors.lastname: Lassila
mesh_terms: D002516:Ceramics; D017076:Computer-Aided Design; D001840:Dental Bonding; D003738:Dental Cements; D003764:Dental Materials; D003799:Dental Stress Analysis; D006858:Hydrofluoric Acid; D008422:Materials Testing; D049329:Nanostructures; D011108:Polymers; D019279:Resin Cements; D012117:Resins, Synthetic; D033081:Shear Strength
chemical_list: D003738:Dental Cements; D003764:Dental Materials; D011108:Polymers; D019279:Resin Cements; D012117:Resins, Synthetic; C023506:Glass ceramics; D006858:Hydrofluoric Acid
keywords: Micro-shear bond strength; Nanoceramic; Polymer-infiltrated; Resin