title: Comparative Morphologic Evaluation and Occluding Effectiveness of Nd: YAG, CO2 and Diode Lasers on Exposed Human Dentinal Tubules: An Invitro SEM Study.
abstract: BACKGROUND
  Dentinal hypersensitivity is one of the most common problem, encountered in dental practice but has least predictable treatment outcome. The advent of lasers in dentistry has provided an additional therapeutic option for treating dentinal hypersensitivity. Although various lasers have been tried over a period of time to treat dentinal hypersensitivity, but still the doubt persist as to which laser leads to maximum dentinal tubular occlusion and is most suitable with minimal hazardous effects.
  
  
  OBJECTIVE
  To compare the effects of Nd: YAG, CO2 and 810-nm diode lasers on width of exposed dentinal tubule orifices and to evaluate the morphologic changes on dentinal surface of human tooth after laser irradiation by scanning electron microscope (SEM).
  
  
  METHODS
  Forty root specimens were obtained from ten freshly extracted human premolars, which were randomly divided into four groups of ten each. Group I: control group treated with only saline, Group II: Nd:YAG laser, Group III: CO2 laser and Group IV: 810-nm diode laser. The specimens were examined using SEM. After calculating mean tubular diameter for each group, the values were compared statistically using parametric one-way ANOVA test and Turkey's post hoc multiple comparison test.
  
  
  RESULTS
  All the three lased groups showed a highly statistical significant result with p-value of <0.001 as compared to non-lased group. On intergroup comparison within the lased groups, all the three groups showed statistically significant difference in the reduction of dentinal tubular diameter (p-value < 0.001).
  
  
  CONCLUSIONS
  Nd: YAG laser was found to be most effective, followed by the CO2 laser and 810-nm diode laser was found to be least effective. The morphologic changes like craters, cracks and charring effect of the dentine were seen maximum by the use of CO2 laser.
authors.affiliation: Reader, Department of Periodontology, Faculty of Dental Sciences, SGT University , Gurgaon, Haryana, India .
authors.forename: Mini
authors.initials: M
authors.lastname: Saluja
authors.affiliation: Professor and Head, Department of Periodontology, Faculty of Dental Sciences, SGT University , Gurgaon, Haryana, India .
authors.forename: Harpreet Singh
authors.initials: HS
authors.lastname: Grover
authors.affiliation: Postgraduate Student, Department of Periodontology, Faculty of Dental Sciences, SGT University , Gurgaon, Haryana, India .
authors.forename: Pankaj
authors.initials: P
authors.lastname: Choudhary
keywords: Cracks; Dentinal hypersensitivity; Dentinal tubules; Hydroxyapatite crystals