title: Effect of electrical discharge machining on dental Y-TZP ceramic-resin bonding.
abstract: OBJECTIVE
  The study determined (i) the effects of electrical discharge machining (EDM) on the shear-bond strength (SBS) of the bond between luting resin and zirconia ceramic and (ii) zirconia ceramic's flexural strength with the three-point bending (TPB) test.
  
  
  METHODS
  Sixty 4.8mm×4.8mm×3.2mm zirconia specimens were fabricated and divided into four groups (n=15): SBG: sandblasted+silane, TSCG: tribochemical silica coated+silane, LTG: Er:YAG laser treated+silane, EDMG: EDM+silane. The specimens were then bonded to a composite block with a dual-cure resin cement and thermal cycled (6000 times) prior to SBS testing. The SBS tests were performed in a universal testing machine. The SBS values were statistically analyzed using ANOVA and Tukey's test. To determine flexural strength, sixty zirconia specimens were prepared and assigned to the same groups (n=15) mentioned earlier. After surface treatment TPB tests were performed in a universal testing machine (ISO 6872). The flexural strength values were statistically analyzed using ANOVA and Tukey's test (α=0.05).
  
  
  RESULTS
  The bond strengths for the four test groups (mean±SD; MPa) were as follows: SBG (Control), 12.73±3.41, TSCG, 14.99±3.14, LTG, 7.93±2.07, EDMG, 17.05±2.71. The bond strength of the EDMG was significantly higher than those of the SBG and LTG (p<0.01). The average flexural strength values for the groups SBG (Control), TSCG, LTG and EDMG were 809.47, 800.47, 679.19 and 695.71MPa, respectively (p>0.05).
  
  
  CONCLUSIONS
  The EDM process improved the SBS. In addition, there was no significant adverse effect of EDM on the flexural strength of zirconia.
authors: Bafra Public Oral Health Center, Samsun, Turkey. Electronic address: dtnergiz@gmail.com.
authors: Nergiz
authors: N
authors: Rona
authors: Department of Prosthodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey. Electronic address: muyenisey@omu.edu.tr.
authors: Murat
authors: M
authors: Yenisey
authors: Department of Mechanical Engineering, Faculty of Engineering, Gazi University, Ankara, Turkey. Electronic address: kucukturkg@gmail.com.
authors: Gokhan
authors: G
authors: Kucukturk
authors: Department of Manufacturing Engineering, Faculty of Technology, Gazi University, Ankara, Turkey. Electronic address: hgurun@gazi.edu.tr.
authors: Hakan
authors: H
authors: Gurun
authors: Department of Mechatronics Engineering, Faculty of Engineering, Cankaya University, Ankara, Turkey. Electronic address: cogun@cankaya.edu.tr.
authors: Can
authors: C
authors: Cogun
authors: Department of Materials Science and Engineering, Faculty of Engineering, Cankaya University, Ankara, Turkey. Electronic address: ziyaesen@cankaya.edu.tr.
authors: Ziya
authors: Z
authors: Esen
mesh_terms: D001840:Dental Bonding; D055664:Electrochemical Techniques / Q000379:methods*; D006108:Graphite; D008422:Materials Testing / Q000379:methods*; D011208:Powders; D012117:Resins, Synthetic; D033081:Shear Strength; D015019:Yttrium; D015040:Zirconium
chemical_list: D011208:Powders; D012117:Resins, Synthetic; C499362:yttria stabilized tetragonal zirconia; D015019:Yttrium; D006108:Graphite; D015040:Zirconium; C028541:zirconium oxide
keywords: Bonding strength; Electrical discharge machining; Flexural strength; Graphite powder; Zirconia ceramic