title: The effect of Er,Cr:YSGG laser irradiation on the push-out bond strength of RealSeal self-etch sealer.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effect of an erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser on the push-out bond strength of RealSeal Self-Etch (SE) sealer.
  
  
  BACKGROUND
  Various methods are used for smear layer removal in endodontics, such as the application of Er,Cr:YSGG lasers. This laser system may influence the bond strength of resin-based sealers.
  
  
  METHODS
  Sixty single-rooted extracted teeth were selected. After root canal preparation, samples were divided into two experimental groups and one positive control group (n=20 per group). In group 1, the smear layer was removed by irrigation with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl). In group 2, the smear layer was removed using a 2.78 μm Er,Cr:YSGG laser with radial firing tips (RFT3) (parameters: 1.5 W, 140 μs, 20 Hz, and 15% water to 15% air ratio), moving at 2 mm/sec in an apico-coronal direction. Group 3 served as a positive control group. Five specimens from each group were selected for scanning electron microscope (SEM) observation. The remaining 45 roots were obturated with RealSeal SE/Resilon and subjected to push-out tests. Data were analyzed using one way analysis of variance (ANOVA) and Tamhane's test.
  
  
  RESULTS
  The results showed no significant difference between push-out bond strength of root canal fillings in the EDTA+NaOCl group and the 1.5 W laser group (p>0.05). The positive control group showed the lowest push-out bond strength.
  
  
  CONCLUSIONS
  The results of the present study indicate that the application of an Er,Cr:YSGG laser with radial firing tips did not adversely affect the push-out bond strength of RealSeal SE sealer to dentin.
authors.affiliation: 1 Dental Student's Scientific Research Center (DSSRC), School of Dentistry, Tehran University of Medical Sciences , Tehran, Iran .
authors.forename: Sara
authors.initials: S
authors.lastname: Ehsani
authors.forename: Behnam
authors.initials: B
authors.lastname: Bolhari
authors.forename: Ardavan
authors.initials: A
authors.lastname: Etemadi
authors.forename: Abdollah
authors.initials: A
authors.lastname: Ghorbanzadeh
authors.forename: Yazdan
authors.initials: Y
authors.lastname: Sabet
authors.forename: Ali
authors.initials: A
authors.lastname: Nosrat
mesh_terms: D001840:Dental Bonding; D006801:Humans; D066298:In Vitro Techniques; D053844:Lasers, Solid-State; D064347:Microscopy, Electrochemical, Scanning; D014092:Tooth Root