title: Comparison of Microleakage of Glass Ionomer Restoration in Primary Teeth Prepared by Er: YAG Laser and the Conventional Method.
abstract: OBJECTIVE
  One of the main criteria in evaluating the restorative materials is the degree of microleakage. The aim of this study was to compare the microleakage of glass ionomer restored cavities prepared by Er:YAG laser or turbine and bur.
  
  
  METHODS
  Twenty extracted caries-free deciduous posterior teeth were selected for this study. The teeth were randomly divided into two groups for cavity preparation. Cavities in group one were prepared by high speed turbine and bur. In the second group, Er:YAG laser with a 3W output power, 300 mJ energy and 10 Hz frequency was used. Cavities were restored with GC Fuji II LC. After thermocycling, the samples were immersed into 0.5% methylene blue solution. They were sectioned for examination under optic microscope.
  
  
  RESULTS
  The Wilcoxon signed ranks test showed no significant difference between microleakage of the laser group and the conventional group (P>0.05).
  
  
  CONCLUSIONS
  Er:YAG laser with its advantages in pediatric dentistry may be suggested as an alternative device for cavity preparation.
authors.affiliation: Associate Professor Department of Pediatric, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Ghandehari
authors.forename: G
authors.initials: G
authors.lastname: Mighani
authors.forename: S
authors.initials: S
authors.lastname: Shahabi
authors.forename: N
authors.initials: N
authors.lastname: Chiniforush
authors.forename: Z
authors.initials: Z
authors.lastname: Shirmohammadi
keywords: Er:YAG laser; Glass ionomer; Microleakage