title: Pulpal blood flow recorded from human premolar teeth with a laser Doppler flow meter using either red or infrared light.
abstract: OBJECTIVE
  To compare red (635 nm) and infrared (780 nm) light for recording pulpal blood flow from human premolar teeth.
  
  
  METHODS
  Recordings were made from 11 healthy teeth in 9 subjects (aged 16-30 years) using a laser Doppler flow meter (Periflux 4001) equipped with both red and infrared lasers. Average blood flow signals were obtained with both light sources alternately from each tooth under five conditions: intact tooth without opaque rubber dam, intact tooth with dam, after injecting local anaesthetic (3% Mepivacaine) (LA) over the apex of the tooth and cavity preparation to almost expose the pulp, after removal and replacement of the pulp, and with the root canal empty.
  
  
  RESULTS
  With infrared light, the dam significantly decreased the mean blood flow by 80%. Injecting LA and cavity preparation had no significant effect. Removal and replacement of the pulp reduced the mean blood flow by 58%. There was no further change when the pulp was removed. With red light, the dam reduced the signal from intact teeth by 60%. Injecting LA and cavity preparation had no significant effect. The signal fell by 67% after pulp removal and replacement and did not change significantly when the pulp was removed.
  
  
  CONCLUSIONS
  Opaque rubber dam minimises the contribution of non-pulpal tissues to the laser Doppler signal recorded from premolars. Using dam, the pulp contributed about 60% to the blood flow signal with both red and infrared light. The difference between them in this respect was not significant.
authors.affiliation: Department of Physiology and Biochemistry, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Kanittha
authors.initials: K
authors.lastname: Kijsamanmith
authors.forename: Siriporn
authors.initials: S
authors.lastname: Timpawat
authors.forename: Noppakun
authors.initials: N
authors.lastname: Vongsavan
authors.forename: Bruce
authors.initials: B
authors.lastname: Matthews
mesh_terms: D000293:Adolescent; D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage; D001641:Bicuspid / Q000098:blood supply*; D003737:Dental Cavity Preparation / Q000379:methods; D003782:Dental Pulp / Q000098:blood supply*; D003786:Dental Pulp Cavity / Q000098:blood supply; D006801:Humans; D007259:Infrared Rays; D017078:Laser-Doppler Flowmetry / Q000295:instrumentation*; D007834:Lasers; D008619:Mepivacaine / Q000008:administration & dosage; D055100:Optical Fibers; D011670:Pulpectomy; D012039:Regional Blood Flow / Q000502:physiology; D016733:Rubber Dams; D019227:Tooth Apex / Q000098:blood supply; D019228:Tooth Crown / Q000098:blood supply; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D008619:Mepivacaine