title: Effect of Argon Laser on Enamel Demineralization around Orthodontic Brackets: An In Vitro Study.
abstract: OBJECTIVE
  This study was designed to evaluate the effect of argon laser irradiation on development and progress of enamel demineralization around orthodontic brackets.
  
  
  METHODS
  Fifty caries-free, intact human premolars were randomly assigned to one of the following five equal groups: Groups 1 (control) and 2: The brackets were bonded using conventional halogen light for 40s and argon laser for 10s, respectively. Teeth in group 3 were lased with argon laser for 10s before bracket bonding with halogen light. Group 4 was the same as group 3 except that brackets were also bonded with argon laser. In group 5 samples were bonded conventionally, immersed in an artificial caries solution for two days and then irradiated for 10s with argon laser. All samples were subjected to demineralization by artificial caries solution for 10 days. After bracket removal, samples were buccolingually sectioned and evaluated by polarized light microscopy. Decalcified lesion depth in each section was measured by a trained examiner in a blind fashion. Data were analyzed in SPSS 14 using one-way ANOVA and Tukey's HSD post hoc test.
  
  
  RESULTS
  The control group showed the greatest mean lesion depth while group 5 revealed the lowest. The laser-treated groups had significantly lower mean lesion depth compared with the control group (P<0.05) except for group 4 (P=0.192).
  
  
  CONCLUSIONS
  Argon laser irradiation for 10s before or during bracket bonding can increase caries resistance of intact and demineralized enamel.
authors.affiliation: Associated professor, Orthodontic dept., Dental faculty, Hamadan university of medical sciences, Hamadan, Iran.
authors.forename: Amirfarhang
authors.initials: A
authors.lastname: Miresmaeili
authors.affiliation: Department of Medical Engineering, Amirkabir University, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Etrati Khosroshahi
authors.affiliation: Department of Oral Pathology, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Pouya
authors.initials: P
authors.lastname: Motahary
authors.affiliation: Associated Professor, Member of Dental Research Center, Department of Operative Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Loghman
authors.initials: L
authors.lastname: Rezaei-Soufi
authors.affiliation: Professor, Department of Biostatistics, Faculty of Health, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Mahjub
authors.affiliation: Private Dentist, Orthodontic Department, Dental Faculty, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Dadashi
authors.affiliation: Associated Professor, Orthodontic Department, Dental Faculty, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Farhadian
keywords: Argon laser; Demineralization; Enamel; Orthodontics