title: Effect of thermomechanical aging on bond strength and interface morphology of glass fiber and zirconia posts bonded with a self-etch adhesive and a self-adhesive resin cement to natural teeth.
abstract: BACKGROUND
  Information regarding the effect of thermomechanical aging (TMA) on the bond strength of luting cements to root canal dentin and endodontic posts is limited.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the effect of TMA on the bond strength of fiber and zirconia posts bonded to root canal dentin with 2 different resin cements with microtensile and scanning electron microscopic evaluation.
  
  
  METHODS
  Eighty extracted single-rooted human premolars were endodontically treated and restored with either a glass fiber post (FP) or a zirconia post (ZP) with 2 commercially available resin luting cements. The teeth were divided into 2 main groups. In the first group, posts (n=40) were bonded with a self-etch adhesive cement (SEAC). In the second group (n=40), posts were bonded using a self-adhesive cement (SAC). During the first aging phase, all specimens in each group were stored in distilled water for 30 days at 37°C. During the second phase, half of the specimens in each group were subjected to the TMA. The test groups were as follows: FP/SEAC, FP/SEAC+TMA, ZP/SEAC, ZP/SEAC+TMA, FP/SAC, FP/SAC+TMA, ZP/SAC, and ZP/SAC+TMA. The bond strength was measured with a microtensile test. Data were analyzed by 3-way analysis of variance and the Tukey honest significant different test (α=.05).
  
  
  RESULTS
  FP/SEAC at 30 days was higher than in the other groups. However, bond strength values were significantly reduced in this group after TMA (P<.001).
  
  
  CONCLUSIONS
  Bond strength values and physical properties of SEAC with higher filler content were more affected by the TMA than those of SALC. According to scanning electron microscopic observation, TMA also affected the micromorphologic interface between the posts and the resin cements as well as between the resin cements and the root canal dentin.
authors.affiliation: Associate Professor, Istanbul University, Faculty of Dentistry, Department of Operative Dentistry, Eskişehir, Turkey. Electronic address: bcyaman@ogu.edu.tr.
authors.forename: Batu Can
authors.initials: BC
authors.lastname: Yaman
authors.affiliation: Professor, Department of Preventive and Restorative Sciences, University of Pennsylvania School of Dental Medicine, Philadelphia, Pa.
authors.forename: Fusun
authors.initials: F
authors.lastname: Ozer
authors.affiliation: Associate Professor, Department of Fixed Prosthodontics, Aichi Gakuin University School of Dentistry, Nagoya, Japan.
authors.forename: Takuro
authors.initials: T
authors.lastname: Takeichi
authors.affiliation: Associate Professor, Department of Endodontics, University of Pennsylvania School of Dental Medicine, Philadelphia, Pa.
authors.forename: Bekir
authors.initials: B
authors.lastname: Karabucak
authors.affiliation: Professor, Department of Operative Dentistry, Istanbul University, Faculty of Dentistry, Eskişehir, Turkey.
authors.forename: Fatma
authors.initials: F
authors.lastname: Koray
authors.affiliation: Professor, Chairman of Department of Preventive and Restorative Sciences, University of Pennsylvania School of Dental Medicine, Philadelphia, Pa.
authors.forename: Markus B
authors.initials: MB
authors.lastname: Blatz
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003786:Dental Pulp Cavity / Q000648:ultrastructure; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure; D004853:Epoxy Resins / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011176:Post and Core Technique / Q000295:instrumentation*; D019279:Resin Cements / Q000737:chemistry*; D018915:Root Canal Preparation / Q000379:methods; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D019553:Tooth, Nonvital / Q000628:therapy; D014867:Water / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003764:Dental Materials; D004853:Epoxy Resins; D019279:Resin Cements; C009753:fiberglass; D014867:Water; D015040:Zirconium; C028541:zirconium oxide