title: Removal of two types of root canal filling material using pulsed Nd:YAG laser irradiation.
abstract: OBJECTIVE
  The aim of this study was to examine the usefulness of a pulsed Nd:YAG laser in removing two types of endodontic obturation material from the root canal in vitro.
  
  
  BACKGROUND
  Recently, a fine flexible glass fiber made of quartz has been developed to transmit the laser beam more effectively and permit its concentration in a specific area. This has increased the potential usefulness of the Nd:YAG laser in root canal treatment.
  
  
  METHODS
  The time required for removing the root canal obturation material (Gutta-percha cones and, Sealapex or AH26) by means of either Nd:YAG laser irradiation or a conventional method (Gates Glidden drills and K files) was measured. Contact microradiography was used to assess the radiopacity of the root canals before and after the removal of obturation material. The surfaces of the root canal after removal of the obturation materials were also observed by scanning electron microscopy.
  
  
  RESULTS
  Although none of the methods used in this study resulted in complete removal of debris from the root canal wall, the time required for the removal of any of the root canal obturation materials using laser ablation was significantly shorter than that required using the conventional method (p < 0.05). It appeared that some orifices of the dentinal tubules were blocked with melted dentin following laser irradiation.
  
  
  CONCLUSIONS
  Nd:YAG laser irradiation is an effective tool for the removal of root canal obturation materials, and may offer advantages over the conventional method.
authors.affiliation: Pulp Biology and Endodontics, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. t.anjo.endo@tmd.ac.jp
authors.forename: Tomoo
authors.initials: T
authors.lastname: Anjo
authors.forename: Arata
authors.initials: A
authors.lastname: Ebihara
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takeda
authors.forename: Masaaki
authors.initials: M
authors.lastname: Takashina
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Sunakawa
authors.forename: Hideaki
authors.initials: H
authors.lastname: Suda
mesh_terms: D001729:Bismuth / Q000627:therapeutic use; D003786:Dental Pulp Cavity / Q000528:radiation effects; D004338:Drug Combinations; D004708:Endodontics; D004853:Epoxy Resins / Q000627:therapeutic use; D006171:Gutta-Percha / Q000627:therapeutic use; D006801:Humans; D053685:Laser Therapy; D008855:Microscopy, Electron, Scanning; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000379:methods*; D012834:Silver / Q000627:therapeutic use; D014025:Titanium / Q000627:therapeutic use
chemical_list: D004338:Drug Combinations; D004853:Epoxy Resins; D012387:Root Canal Filling Materials; D012834:Silver; C028044:epoxy resin AH-26; D006171:Gutta-Percha; D014025:Titanium; D001729:Bismuth