title: Comparison of Dentin Permeability After Tooth Cavity Preparation with Diamond Bur and Er:YAG Laser.
abstract: OBJECTIVE
  The aim of this study was to compare the permeability of dentin after using diamond bur and Er:YAG laser.
  
  
  METHODS
  Seventy-two recently extracted, intact, and restoration-free human permanent molars were used in this study. The samples were randomly divided into three groups of 24 each and class I cavities were prepared as follows. Group 1: High speed diamond bur with air and water spray. Group 2: Er:YAG laser. Group 3: Er:YAG laser followed by additional sub-ablative laser treatment. Each group consisted of two subgroups with different cavity depths of 2mm and 4mm. The entire cavity floor was in dentin. Two samples from each subgroup were observed under scanning electron microscope (SEM). The external surfaces of other samples were covered with nail varnish (except the prepared cavity) and immersed in 0.5% methylene blue solution for 48 hours. After irrigation of samples with water, they were sectioned in bucco-lingual direction. Then, the samples were evaluated under a stereomicroscope at ×160 magnification. The data were analyzed using two-way ANOVA and Tukey's HSD test.
  
  
  RESULTS
  Two-way ANOVA showed significant difference in permeability between groups 2 and 3 (laser groups with and without further treatment) and group 1 (bur group). The highest permeability was seen in the group 1. There was no significant difference in dentin permeability between groups 2 and 3 and no significant difference was observed between different depths (2mm and 4mm).
  
  
  CONCLUSIONS
  Cavities prepared by laser have less dentin permeability than cavities prepared by diamond bur.
authors.affiliation: Associate Professor, Laser Research Center in Dentistry (LRCD), Dental Research Institute, Department of Restorative Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Hasani Tabatabaei
authors.affiliation: Dentist, Tehran, Iran.
authors.forename: Sara
authors.initials: S
authors.lastname: Shirmohammadi
authors.affiliation: Professor, Department of Restorative Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Esmaeil
authors.initials: E
authors.lastname: Yasini
authors.affiliation: Associate Professor, Laser Research Center in Dentistry (LRCD), Dental Research Institute, Department of Restorative Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mansoureh
authors.initials: M
authors.lastname: Mirzaei
authors.affiliation: Assistant Professor, Laser Research Center in Dentistry (LRCD), Dental Research Institute, Department of Restorative Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Sakineh
authors.initials: S
authors.lastname: Arami
authors.affiliation: Associate Professor, Laser Research Center in Dentistry (LRCD), Dental Research Institute, Department of Restorative Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Kermanshah
authors.affiliation: Assistant Professor, Laser Research Center in Dentistry (LRCD), Dental Research Institute, Department of Restorative Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ladan
authors.initials: L
authors.lastname: Ranjbar Omrani
authors.affiliation: Assistant Professor, Department of Restorative Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Azar
authors.initials: A
authors.lastname: Alimi
authors.affiliation: PhD Candidate of Laser Dentistry, Laser Research Center of Dentistry, Dental Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nasim
authors.initials: N
authors.lastname: Chiniforush
authors.affiliation: Assistant Professor, Department of Restorative Dentistry, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Afrooz
authors.initials: A
authors.lastname: Nakhostin
authors.affiliation: Assistant Professor, Laser Research Center in Dentistry (LRCD), Dental Research Institute, Department of Restorative Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Abbasi
keywords: Dental Cavity Preparation; Dentin Permeability; Lasers, Solid-State