The effect of cigarette smoking on gingival blood flow in humans.

This paper presents the acute effects of cigarette smoking on blood flow to the gingiva in 12 young smokers. Relative gingival blood flow (GBF) was measured by a laser Doppler fiberoptic probe placed 1 mm into the buccal sulcus of tooth no. 26. The probe continuously measured the flux of blood cells (velocity X number of cells) in the gingival crest. Relative skin blood flow (SBF) to the forearm and heart rate were also monitored continously; blood pressure (BP) was assessed at 5-min intervals. After resting for 5 min, subjects sham smoked an unlighted cigarette for 5 min, then smoked the cigarette, and finally rested for 25 min afterwards. Mean changes from resting for all variables were compared to sham smoking for each 5 min block. Mean GBF rose significantly above sham smoking values during smoking, and remained elevated during the first 5 min after smoking (p less than 0.05). Mean SBF decreased slightly during and after smoking, but the changes were not significantly depressed compared to sham smoking (p greater than 0.05). During smoking, BP and heart rate increased significantly over sham smoking (p less than 0.05). GBF increased almost linearily when the probe was placed into the gingival sulcus; this phenomenon did not occur when the probe was placed externally to the gingival crest. The theory that smoking impairs gingival blood flow may not be true in humans.