title: Pulsed Nd:YAG laser application to one-visit treatment of infected root canals in dogs: a histopathological study.
abstract: OBJECTIVE
  In this study, the effects of pulsed Nd:YAG laser irradiation during root canal treatment of infected teeth were investigated histopathologically in dogs.
  
  
  BACKGROUND
  Effects of Nd:YAG laser on infected root canal treatment have not been reported in vivo.
  
  
  METHODS
  One hundred thirty-five teeth with a single root, including incisors and premolars, in 15 healthy adult beagle-strain dogs were used in this study. After inducing infection in the teeth, each root canal was shaped with at least a # 40 K-file, then the canal was irradiated using the following parameters: 1 W, 30 pps for 1 and 2 sec; 2 W, 30 pps for 1 and 2 sec. Efficacy of debris removal and evaporation on the root canal walls at 2 weeks, and the degree of inflammation of the periapical region at 2, 4, and 8 weeks after laser irradiation were examined histopathologically by light microscopy.
  
  
  RESULTS
  Effective debris removal was observed in all cases of the laser-treated groups. No evaporation was observed except at the conditions of 2 W for 2 sec. Inflammation of periapical region in the laser-treated groups was similar in the control group at 2 weeks, but was significantly less than that in the control group at 8 weeks (p < 0.05).
  
  
  CONCLUSIONS
  These results suggest that pulsed Nd:YAG laser is useful for one-visit root canal treatment of infected teeth in dogs, if appropriate parameters are selected, and this is a potential therapy for human apical lesions of teeth.
authors.affiliation: Department of Endodontics, Showa University School of Dentistry, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Koba
authors.forename: Y
authors.initials: Y
authors.lastname: Kimura
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: T
authors.initials: T
authors.lastname: Takeuchi
authors.forename: T
authors.initials: T
authors.lastname: Ikarugi
authors.forename: T
authors.initials: T
authors.lastname: Shimizu
authors.forename: K
authors.initials: K
authors.lastname: Saito
mesh_terms: D000818:Animals; D016009:Chi-Square Distribution; D003786:Dental Pulp Cavity / Q000473:pathology / Q000528:radiation effects*; D004285:Dogs; D005069:Evaluation Studies as Topic; D053685:Laser Therapy; D009354:Neodymium; D010485:Periapical Periodontitis / Q000473:pathology / Q000532:radiotherapy*; D018915:Root Canal Preparation / Q000295:instrumentation*; D014092:Tooth Root / Q000473:pathology / Q000528:radiation effects*
chemical_list: D009354:Neodymium