title: Effect of Air Abrasion and Erbium-Doped Yttrium Aluminum Garnet (Er: YAG) laser preparation on Shear Bond Strength of Composite to Dentin.
abstract: BACKGROUND
  The aim of this study was to assess shear bond strength of composite to dentin after air abrasion and laser treatment.
  
  
  METHODS
  40 human extracted molars divided into 4 groups (n=10) received the following treatments. Group 1: carbide bur, Group 2: air abrasion with aluminum oxide 50 μm, Group 3: irradiated with Erbium-Doped Yttrium Aluminum Garnet (Er: YAG) laser (150 mJ/20Hz), Group 4: irradiated with Er:YAG laser (150 mJ/20Hz)+ air. Specimens in all groups were chemically etched with phosphoric acid 37% and treated with bonding agent (single bond 3M). Then, composite build-up was performed by tygon tube. After storage in distilled water at 37°c for one week, all specimens were subjected to a shear bond strength test with universal testing machine. Data were analyzed with ANOVA and T-Test.
  
  
  RESULTS
  The mean and standard deviation of shear bond strength of the 4 groups were 20.8±6.76, 14.98±3.98, 11.43±4.36 and 14.95± 3.18 MPa, respectively.
  
  
  CONCLUSIONS
  Air abrasion after laser treatment improved the shear bond strength.
authors.affiliation: Department of Operative Dentistry, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ayoub
authors.initials: A
authors.lastname: Pahlavan
authors.affiliation: Dental Students' Research Center, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mobin
authors.initials: M
authors.lastname: Mehmanchi
authors.affiliation: Department of Operative Dentistry and Dental Research Center, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ladan
authors.initials: L
authors.lastname: Ranjbar Omrani
authors.affiliation: Laser Research Center of Dentistry, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nasim
authors.initials: N
authors.lastname: Chiniforush
keywords: Er-YAG laser; dental air abrasion; dentin