title: Effect of Er,Cr:YSGG laser treatment on microshear bond strength of zirconia to resin cement before and after sintering.
abstract: OBJECTIVE
  To evaluate the effect of Er,Cr:YSGG laser treatment on microshear bond strength of zirconia to resin cement before and after sintering.
  
  
  METHODS
  Ninety pre-sintered yttrium-stabilized tetragonal zirconia specimens (4 × 3 × 2 mm) were divided into 6 groups (n = 15). In group C, sintered zirconia was not treated (control group). In groups AS2 and AS3, sintered zirconia blocks were irradiated by Er,Cr:YSGG using a power of 2 and 3 W, respectively. Groups PS2 and PS3 consisted of pre-sintered blocks conditioned by Er,Cr:YSGG at 2 and 3 W, respectively. In group AA, sintered zirconia was air abraded with 50-μm alumina powder. One block was made using the same preparations as mentioned above and was morphologically assessed by SEM. Microcylinders of Panavia F 2.0 were placed on the treated surface of the groups. Samples were incubated at 37°C and 98% humidity for 48 h and then subjected to microshear bond strength testing. The mode of failure was evaluated. Data were analyzed by one-way ANOVA and Tukey's HSD test (p < 0.05).
  
  
  RESULTS
  There was a statistically significant difference between group AA and the others (p < 0.0001). A significant difference was also noted between groups AS3 and C (p = 0.031). Complete surface roughness was seen in group AA and the bond failure was mostly cohesive, while in laser-treated groups, the surfaces roughness was much lower vs other groups, and the mode of failure was mostly adhesive.
  
  
  CONCLUSIONS
  Laser treatment of pre-sintered Y-TZP cannot be recommended for improving the bond. Although sandblasting of sintered Y-TZP yielded better results than the rest of the groups, 3 W power after sintering can also be effective in enhancing the bonding strength of resin cement to zirconia.
authors.forename: Amir
authors.initials: A
authors.lastname: Ghasemi
authors.forename: Hamid
authors.initials: H
authors.lastname: Kermanshah
authors.forename: Maryam
authors.initials: M
authors.lastname: Ghavam
authors.forename: Afshin
authors.initials: A
authors.lastname: Nateghifard
authors.forename: Hassan
authors.initials: H
authors.lastname: Torabzadeh
authors.forename: Ardalan
authors.initials: A
authors.lastname: Nateghifard
authors.forename: Kaveh
authors.initials: K
authors.lastname: Zolfagharnasab
authors.forename: Hadi
authors.initials: H
authors.lastname: Ahmadi
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D017554:Carbon Compounds, Inorganic / Q000737:chemistry; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods; D003775:Dental Polishing / Q000379:methods; D006358:Hot Temperature; D006813:Humidity; D053844:Lasers, Solid-State; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011829:Radiation Dosage; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D017655:Silicon Compounds / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D015019:Yttrium / Q000737:chemistry / Q000528:radiation effects*; D015040:Zirconium / Q000737:chemistry / Q000528:radiation effects*
chemical_list: D017554:Carbon Compounds, Inorganic; C438843:Panavia-Fluoro; D019279:Resin Cements; D017655:Silicon Compounds; C499362:yttria stabilized tetragonal zirconia; D015019:Yttrium; D015040:Zirconium; D000537:Aluminum Oxide; C022088:silicon carbide