Microcirculatory Changes of Human Gingiva Induced by Vasoactive Reflexes and Toothbrushing

Objectives: The laser speckle contrast imging is a new non-invasive, reproducible blood flow testing method in two dimensions.
Our aim was to detect the microcirculation changes in different parts of the gingiva and oral mucosa and to work out some simple tests to develop clinical tests upon in order to be able to examine the differences of healthy and pathological circumstances.
Methods: The participating patients in our experiment were 18-40 years old healthy, non-smoking, non-pregnant, non-regular alcohol consumer men and women. After their arrival we kept a 15-minute rest period, subsequently their blood pressure was measured on the upper arm at predefined intervals. During the investigation patients were in recumbent position in a dental chair with their head fixed on a vacuum pillow in a thermostatically controlled room (26 ^oC). The blood flow changes in the papilla between 33 and 32 teeth together with the region of attached gingiva and oral mucosa were monitored under systemic (30% of the maximal handgrip retained for 3 min) and local (provoking erythema by means of drawing a wire over the examined gingiva segment) reflexes, furthermore after brushing (sweeping ten times in apico–coronal direction with a medium brush) using LASCA. Our data were evaluated by mixed model statistical method.
Results: Despite the systemic blood pressure increase by 35 Hgmm during the handgrip test there were no changes in the blood flow of the gingiva as opposed to the oral mucosa. In case when the gingiva was stimulated by wire or toothbrush, the blood flow increased significantly.
Conclusions: The fact that despite the increase in blood pressure the blood flow did not change suggests that autoregulation exists in the gingival vessels. Regarding our measurements it may be advantageous that systemic blood pressure changes do not influence the local blood circulation during the study and therefore they are not likely to cause a measurement error. The blood flow enhancing effect of the mechanical stimulation is a defensive response and it could be advantageous for the health of the ginigva during oral hygiene activities.