title: Evaluation of a commercial primer for bonding of zirconia to two different resin composite cements.
abstract: OBJECTIVE
  To evaluate the effects of a commercial zirconia primer (Choice or RelyX Unicem) on shear bond strength (SBS) of two different resin composite cements - Choice (a conventional bis-GMA-based resin cement) and RelyX Unicem (self-adhesive resin cement) - to zirconia.
  
  
  METHODS
  Zirconia blocks were manufactured and randomly divided into 5 main groups (n = 20) that received surface treatments and cements as follows: no surface treatment, Choice and RelyX Unicem (groups C and U, resp.); tribochemical silica coating followed by silanization, Choice (group SSC); application of a zirconia primer, Choice and RelyX Unicem (groups ZC and ZU, resp.). Light-curing composite resin cylinders were prepared and bonded on the prepared zirconia blocks using the two different resin cements. Half of the specimens in each group were stored in water for 24 h, and half were aged by 50 days of water storage followed by thermocycling (12,000 cycles between 5°C and 55°C). Thereafter, all of them were submitted to the SBS test. Fourier transmission infrared (FT-IR) spectrum analysis and gas mass spectrometry (MS) analysis were adopted for characterization of the zirconia primer.
  
  
  RESULTS
  Statistical analysis of the SBS test showed that group C presented the lowest SBS values and group SSC the highest (p < 0.01). Artificial aging exerted no influence on the SBS of groups U, SSC, ZC, or ZU. FT-IR analysis suggested that benzene rings and carboxylic groups exist in the zirconia primer. MS analysis detected that 2-hydroxyethyl methacrylate, triethylamine, ethyl-4-dimethylaminobenzoate, ethanol, and water are contained in the primer.
  
  
  CONCLUSIONS
  The zirconia primer and self-adhesive resin cement increased the SBS of zirconia.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.forename: Haifeng
authors.initials: H
authors.lastname: Xie
authors.forename: Xin
authors.initials: X
authors.lastname: Song
authors.forename: Michael Francis
authors.initials: MF
authors.lastname: Burrow
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Feimin
authors.initials: F
authors.lastname: Zhang
mesh_terms: D000179:Acrylates / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D005021:Ethylamines / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D058610:Isobutyrates / Q000737:chemistry; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D011422:Propionates / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry; D015019:Yttrium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*; D062366:para-Aminobenzoates / Q000737:chemistry
chemical_list: C551061:2-hydroxyethylpropionate; D000179:Acrylates; C086628:Choice resin cement; D003188:Composite Resins; D003764:Dental Materials; D005021:Ethylamines; D058610:Isobutyrates; D008689:Methacrylates; D011422:Propionates; C483701:Rely X Unicem; D019279:Resin Cements; D012821:Silanes; D062366:para-Aminobenzoates; C499362:yttria stabilized tetragonal zirconia; D014867:Water; C017492:methacryloxypropyltrimethoxysilane; D015019:Yttrium; C030747:ethyl 4-dimethylaminobenzoate; C020380:isobutyric acid; D015040:Zirconium; C036658:acrylic acid; C016162:triethylamine