title: Vapor emissions resulting from Nd:YAG laser interaction with tooth structure.
abstract: The Neodymium:yttrium aluminum garnet (Nd:YAG) dental laser has been cleared by the United States Food and Drug Administration (FDA) for marketing in intraoral soft tissue treatment. The efficacy and safety of the Nd:YAG laser in the treatment of hard dental tissue as well as the effects of dental irradiation on the pulp and periodontium have been investigated. Odors resulting from laser irradiation have been reported, but the nature and toxicity of associated decomposition vapors is unknown and the health consequences of their inhalation have not yet been studied.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to identify vapors emitted during interaction of the Nd:YAG laser with carious human enamel and dentin and sound enamel and dentin coated with organic ink.
  
  
  METHODS
  Vapor emissions were collected from prepared sections of extracted human teeth receiving laser irradiation of 100 mJ and 10 Hz for a duration of 1, 10, or 60 s. Emissions were collected by means of charcoal absorption tubes, and subsequently analyzed using a Gas Chromatograph equipped with Mass Selective (GC/MS) and Flame Ionization Detectors to identify the chemical constituents of the vapors.
  
  
  RESULTS
  No compounds were identified in Nd:YAG laser-treated caries, enamel and dentin. No volatile vapors were identified from samples of tooth materials exposed to the laser for 1 or 10 s. Camphor was positively identified in the test sample which consisted of India ink-coated dentin and the reference sample of India ink-coated glass beads, both exposed to the laser for 60 s. 2,5-norbornadiene was tentatively identified in these samples. The Threshold Limit Value (TLV) of camphor is 2 ppm with a Lethal Dose Level (LDLo) of 50 mg/kg (human oral), while the TLV and LDLo of 2,5-norbornadiene is unknown.
  
  
  CONCLUSIONS
  Occupational and public health safety measures are discussed in this article. Further research is needed to quantify the compounds produced and to determine their toxicity to patients and to dental care providers.
authors.affiliation: Department of Dental Diagnostic and Surgical Sciences, Faculty of Dentistry, University of Manitoba, Winnipeg, Canada. shirleygelskey@umanitoba.ca
authors.forename: S C
authors.initials: SC
authors.lastname: Gelskey
authors.forename: J M
authors.initials: JM
authors.lastname: White
authors.forename: D E
authors.initials: DE
authors.lastname: Gelskey
authors.forename: W
authors.initials: W
authors.lastname: Kremers
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis*; D000535:Aluminum / Q000737:chemistry; D002164:Camphor / Q000032:analysis; D002244:Carbon; D004396:Coloring Agents / Q000737:chemistry*; D003731:Dental Caries / Q000628:therapy; D003737:Dental Cavity Preparation / Q000295:instrumentation*; D003743:Dental Enamel / Q000737:chemistry; D003804:Dentin / Q000737:chemistry; D003814:Dentistry, Operative; D007834:Lasers; D013058:Mass Spectrometry; D009354:Neodymium / Q000737:chemistry; D009636:Norbornanes / Q000032:analysis; D016273:Occupational Exposure / Q000517:prevention & control; D017640:Silicates / Q000737:chemistry; D014835:Volatilization; D015019:Yttrium / Q000737:chemistry
chemical_list: D004396:Coloring Agents; D009636:Norbornanes; D017640:Silicates; C028433:chinese ink; D009354:Neodymium; D015019:Yttrium; D002244:Carbon; D002164:Camphor; D000535:Aluminum; C048294:2,5-norbornadiene