title: Concentration-dependent neurotoxicity of articaine: an electrophysiological and stereological study of the rat sciatic nerve.
abstract: BACKGROUND
  We performed this study to quantify the detrimental effect of intraneural injection of 50 μL of saline, articaine 2%, or articaine 4% in the rat sciatic nerve.
  
  
  METHODS
  Lumbar-evoked electrospinograms from stimulation of the sciatic nerve were recorded before and immediately after injection and again after 3 weeks. Test substance was injected into the right sciatic nerve, and the untreated left sciatic nerve served as control. The animals were killed after the 3-week follow-up, and cross-sections of the sciatic nerve were examined stereologically.
  
  
  RESULTS
  The evoked spinal cord field potential in the articaine groups faded away immediately after injection and was concentration-dependently, significantly more reduced at the 3-week follow-up in comparison with the saline group. The response from the control sides was unaffected in all groups. The number of myelinated axons was unaffected by the treatment. The mean cross-sectional axon area and the mean myelin sheath thickness were significantly reduced in animals injected with articaine 4%.
  
  
  CONCLUSIONS
  These observations indicate concentration-dependent neurotoxic injuries after injection of articaine with a significant difference between 2% and 4% formulations. The mechanical injury of needle penetration with saline injection had no significant effect on nerve conduction or histomorphology.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Rigshospitalet, and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N Denmark. shil@sund.ku.dk
authors.forename: Søren
authors.initials: S
authors.lastname: Hillerup
authors.forename: Merete
authors.initials: M
authors.lastname: Bakke
authors.forename: Jytte Overgaard
authors.initials: JO
authors.lastname: Larsen
authors.forename: Carsten Eckhart
authors.initials: CE
authors.lastname: Thomsen
authors.forename: Thomas Alexander
authors.initials: TA
authors.lastname: Gerds
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism; D002355:Carticaine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology / Q000379:methods*; D005260:Female; D008159:Lumbar Vertebrae / Q000473:pathology; D015233:Models, Statistical; D009186:Myelin Sheath / Q000737:chemistry; D009431:Neural Conduction; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000187:drug effects / Q000473:pathology*; D013997:Time Factors
chemical_list: D002355:Carticaine