title: Long-term tensile bond strength of differently cemented nanocomposite CAD/CAM crowns on dentin abutment.
abstract: OBJECTIVE
  To test the tensile bond strength of luted composite computer aided design/computer aided manufacturing (CAD/CAM) crowns after use of different adhesive systems combined with different resin composite cements on dentin abutments.
  
  
  METHODS
  Human molars (n=200) were embedded in acrylic resin, prepared in a standardized manner and divided into 20 groups (n=10). The crowns were treated as follows: (i) Monobond Plus/Heliobond (MH), (ii) Ambarino P60 (AM), (iii) Visio.link (VL), (iv) VP connect (VP), and (v) non-treated as control groups (CG) and luted with Variolink II (VAR) or Clearfil SA Cement (CSA). Tensile bond strength (TBS) was measured initially (24h water, 37°C) and after aging (5000 thermal cycles, 5/55°C). The failure types were evaluated after debonding. TBS values were analyzed using three-way and one-way ANOVA, followed by post hoc Scheffé-test, and two-sample Student's t-tests.
  
  
  RESULTS
  Among VAR and after aging, CG presented significantly higher TBS (p=0.007) than groups treated with MH, AM and VP. Other groups showed no impact of pre-treatment. A decrease of TBS values after thermal aging was observed within CSA: CG (p=0.002), MH (p<0.001), VL (p<0.001), AM (p=0.002), VP (p<0.001) and within VAR: MH (p=0.002) and AM (p=0.014). Groups cemented with VAR showed significantly higher TBS then groups cemented with CSA: non-aged groups: CG (p<0.001), and after thermal aging: CG (p=0.003), MH (p<0.001), VL (p=0.005), VP (p=0.010).
  
  
  CONCLUSIONS
  According to the study results nano-composite CAD/CAM crowns should be cemented with VAR. Pre-treatment is not necessary if the tested resin composite cements are used.
authors.affiliation: Department of Prosthodontics, Dental School, Ludwig-Maximilians University Munich, Munich, Germany. Electronic address: bogna.stawarczyk@med.uni-muenchen.de.
authors.forename: Bogna
authors.initials: B
authors.lastname: Stawarczyk
authors.affiliation: Department of Prosthodontics, Dental School, Ludwig-Maximilians University Munich, Munich, Germany.
authors.forename: Nicola
authors.initials: N
authors.lastname: Stich
authors.affiliation: Department of Prosthodontics, Dental School, Ludwig-Maximilians University Munich, Munich, Germany.
authors.forename: Marlis
authors.initials: M
authors.lastname: Eichberger
authors.affiliation: Department of Prosthodontics, Dental School, Ludwig-Maximilians University Munich, Munich, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Edelhoff
authors.affiliation: Division of Biostatistics, Institute of Social and Preventive Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Roos
authors.affiliation: Department of Prosthodontics, Dental School, Ludwig-Maximilians University Munich, Munich, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Gernet
authors.affiliation: Department of Prosthodontics, Dental School, Ludwig-Maximilians University Munich, Munich, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Keul
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate; D017076:Computer-Aided Design; D003442:Crowns; D000044:Dental Abutments; D001840:Dental Bonding; D003738:Dental Cements; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis / Q000379:methods*; D006801:Humans; D066298:In Vitro Techniques; D008963:Molar; D053761:Nanocomposites; D019279:Resin Cements; D013718:Tensile Strength
chemical_list: C581302:Clearfil SA; D003738:Dental Cements; C076808:Monobond S; D019279:Resin Cements; C103502:Variolink; D017438:Bisphenol A-Glycidyl Methacrylate; C081713:Visio-Bond
keywords: Adhesive cement; CAD/CAM resins; Crowns; Nanocomposite; Resin composite cement; Tensile bond strength