title: Er:YAG laser activation of sodium hypochlorite for root canal soft tissue dissolution.
abstract: OBJECTIVE
  The aim of this in vitro study was to investigate the effect of Er:YAG laser irradiation on the ability of sodium hypochlorite (NaOCl) to dissolve soft tissue during endodontic procedures.
  
  
  METHODS
  Two acrylic glass plates, each containing a semi-canal, were bolted together to form a complete canal. This geometry permitted one semi-canal to be filled with fine liver sausage of bovine origin dyed by methylene blue and the other with NaOCl (4.00-4.99% available chlorine; Sigma-Aldrich Corporation, St. Louis, MA), which was then activated by Er:YAG laser irradiation (KEY Laser 3; KaVo, Biberach, Germany) using a plain-ended fiber tip and a range of output energy and repetition rate. To achieve relatively low output energy from high input energy, the laser beam was attenuated by placing glass slides in the beam path. The resultant images acquired were analyzed using pixel-based analysis. Samples were statistically analyzed (two-way ANOVA, P < 0.05, univariate, bifactorial; IBM SPSS Statistics 19, SPSS Inc., Chicago, IL).
  
  
  RESULTS
  Both output energy and repetition rate significantly influenced the tissue dissolution ability of NaOCl (P < 0.05).
  
  
  CONCLUSIONS
  Within the limitations of this in vitro study, we conclude that laser activation of NaOCl at 200 mW output power leads to effective soft tissue dissolution. This finding can be of use to endodontists pursuing effective soft tissue dissolution from their irrigants.
authors.affiliation: Center of Dentistry, Department of Prosthetic Dentistry, Ulm University, 89081, Ulm, Germany. katharina.kuhn@uniklinik-ulm.de
authors.forename: Katharina
authors.initials: K
authors.lastname: Kuhn
authors.forename: Heike
authors.initials: H
authors.lastname: Rudolph
authors.forename: Ralph G
authors.initials: RG
authors.lastname: Luthardt
authors.forename: Karl
authors.initials: K
authors.lastname: Stock
authors.forename: Rolf
authors.initials: R
authors.lastname: Diebolder
authors.forename: Raimund
authors.initials: R
authors.lastname: Hibst
mesh_terms: D000818:Animals; D002417:Cattle; D003786:Dental Pulp Cavity / Q000187:drug effects / Q000528:radiation effects*; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D028022:Low-Level Light Therapy; D008954:Models, Biological; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D012390:Root Canal Therapy; D012973:Sodium Hypochlorite / Q000627:therapeutic use*
chemical_list: D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite