Kanittha KijsamanmithSiriporn TimpawatNoppakun VongsavanBruce MatthewsMahidol UniversityUniversity of Bristol2018-05-032018-05-032011-07-01Archives of Oral Biology. Vol.56, No.7 (2011), 629-633000399692-s2.0-79959380542https://repository.li.mahidol.ac.th/handle/20.500.14594/11520Objective: To compare red (635 nm) and infrared (780 nm) light for recording pulpal blood flow from human premolar teeth. Design: 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. © 2010 Elsevier Ltd.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyDentistryMedicineArticleSCOPUS10.1016/j.archoralbio.2010.12.003