title: Effect of HeNe and pulsed Nd:YAG laser irradiation on intradental nerve responses to mechanical stimulation of dentine.
abstract: OBJECTIVE
  Our study aimed to determine how lasing affected intradental nerve responses to dentine stimulation. Study Design/Materials and Methods Intradental nerve activity was recorded from canine teeth of anaesthetised ferrets. Dentine exposed at the tip of the tooth was stimulated with a glass probe. After determining baseline responses to mechanical stimulation, dentine was lased using a pulsed Nd:YAG laser at 60-150mJ/pulse and 10-30 pulses/sec (total power = 0.3-3.0 W).
  
  
  RESULTS
  The HeNe aiming beam alone and Nd:YAG laser at 0.3 W (+ HeNe) had no effect on intradental nerve responses to dentine stimulation. Lasing at 0.6-1. 5 W could either enhance or suppress intradental nerve responses. Lasing at more than or equal to 2.0 W or repeated lasing at lower intensities depressed intradental nerve responses. Lasing often induced intradental nerve firing.
  
  
  CONCLUSIONS
  HeNe lasing had no effect on intradental nerve excitability. The Nd:YAG laser could depress intradental nerve responses to dentine stimulation.
authors.affiliation: Division of Neuroscience, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom. r.orchardson@bio.gla.ac.uk
authors.forename: R
authors.initials: R
authors.lastname: Orchardson
authors.forename: C J
authors.initials: CJ
authors.lastname: Whitters
mesh_terms: D000200:Action Potentials / Q000528:radiation effects; D000818:Animals; D003481:Cuspid / Q000294:innervation; D003782:Dental Pulp / Q000528:radiation effects; D003804:Dentin / Q000528:radiation effects*; D003807:Dentin Sensitivity / Q000532:radiotherapy*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005289:Ferrets; D053685:Laser Therapy; D008839:Microelectrodes; D009431:Neural Conduction / Q000528:radiation effects*; D010812:Physical Stimulation