title: Amalgam Surface Treatment by Different Output Powers of Er:YAG Laser:SEM Evaluation.
abstract: BACKGROUND
  The purpose of this study was to evaluate amalgam surfaces treated by different output powers of erbium-doped yttrium aluminum garnet (Er:YAG) laser by scanning electron microscope (SEM).
  
  
  METHODS
  Twenty-one amalgam blocks (8 mm × 8 mm, 3 mm thickness) were prepared by condensing silver amalgam (into putty impression material. After keeping them for 24 hours in distilled water, they were divided into 7 groups as follow: G1: Er:YAG laser (1 W, 50 mJ), G2: Er:YAG laser (2 W, 100 mJ), G3: Er:YAG laser (3 W, 150 mJ), G4: Sandblast, G5: Sandblast + Er:YAG laser (1 W, 50 mJ), G6: Sandblast +Er:YAG laser (2 W, 100 mJ) and G7: Sandblast +Er:YAG laser (3 W, 150 mJ). Then after preparation of all samples, they were examined by SEM.
  
  
  RESULTS
  The SEM results of amalgam surfaces treated by different output powers of Er:YAG laser showed some pitting areas with non-homogenous irregularities Conclusion: It seems that the application of sandblasting accompanied by Er:YAG laser irradiation can provide proper surface for bonding of orthodontic brackets.
authors.affiliation: Department of Orthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Hashem
authors.initials: MH
authors.lastname: Hosseini
authors.affiliation: Department of Orthodontics, School of Dentistry, Qom University of Medical Sciences, Qom, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Hassanpour
authors.affiliation: Laser Research Center of Dentistry, Dental Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ardavan
authors.initials: A
authors.lastname: Etemadi
authors.affiliation: Department of restorative, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ladan
authors.initials: L
authors.lastname: Ranjbar Omrani
authors.affiliation: Department of Orthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hojat
authors.initials: H
authors.lastname: Darvishpour
authors.affiliation: Laser Research Center of Dentistry, Dental Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nasim
authors.initials: N
authors.lastname: Chiniforush
keywords: Amalgam; Er:YAG lasers; Orthodontic bracket