title: Effects of the iontophoresis of lignocaine with epinephrine into exposed dentine on the sensitivity of the dentine in man.
abstract: OBJECTIVE
  To determine the effects of the iontophoretic application of lignocaine and epinephrine to exposed dentine on the sensitivity of the dentine in human subjects.
  
  
  METHODS
  The experiments were carried out on 13 healthy premolars (13 subjects) that were scheduled for extraction. Dentine was exposed at the tip of the buccal cusp by cutting a cavity which was etched with 35% phosphoric acid. The sensitivity of the dentine was tested with probing and air blast stimuli. The subject indicated the intensity of any pain produced with a score of 0-100. In 7 teeth, the cavity was filled with a solution containing 20% (w/v) lignocaine HCl and 0.1% (w/v) epinephrine HCl, and an iontophoretic current of 120 μA was passed for 90s. The sensitivity of the dentine was tested before and immediately after the treatment and then at 10 min. intervals for 40 min. Pulpal blood flow was recorded at each stage. Control experiments were carried out on 6 teeth using a solution containing only the epinephrine.
  
  
  RESULTS
  The lignocaine plus epinephrine solution completely blocked the pain produced by both forms of stimulus immediately, and this continued for at least 40 min. It also produced an immediate fall in pulpal blood flow that also lasted for at least 40 min. The epinephrine solution had the same effect on pulpal blood flow but no effect on dentine sensitivity.
  
  
  CONCLUSIONS
  The topical application of 20% lignocaine and 0.1% epinephrine, with an iontophoretic current of 120μA for 90s, will anaesthetize exposed, normal, dentine.
authors.affiliation: Department of Pediatric Dentistry, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Watchana
authors.initials: W
authors.lastname: Thongkukiatkun
authors.affiliation: Department of Pediatric Dentistry, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Kadkao
authors.initials: K
authors.lastname: Vongsavan
authors.affiliation: Department of Pharmacology, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Petcharat
authors.initials: P
authors.lastname: Kraivaphan
authors.affiliation: Department of Pediatric Dentistry, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Praphasri
authors.initials: P
authors.lastname: Rirattanapong
authors.affiliation: Department of Oral Biology, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand. Electronic address: noppakun.von@mahidol.ac.th.
authors.forename: Noppakun
authors.initials: N
authors.lastname: Vongsavan
authors.affiliation: Department of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK.
authors.forename: Bruce
authors.initials: B
authors.lastname: Matthews
mesh_terms: D000293:Adolescent; D000779:Anesthetics, Local / Q000008:administration & dosage*; D001641:Bicuspid; D003782:Dental Pulp / Q000098:blood supply*; D003807:Dentin Sensitivity / Q000188:drug therapy*; D004837:Epinephrine / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007478:Iontophoresis / Q000379:methods*; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D059408:Pain Management / Q000379:methods*; D010147:Pain Measurement; D014662:Vasoconstrictor Agents / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D014662:Vasoconstrictor Agents; D008012:Lidocaine; D004837:Epinephrine
keywords: Dentine permeability; Dentine sensitivity; Iontophoresis; Lignocaine; Local anaesthetic; Pain