MICROCIRCULATORY DYNAMICS IN EXPERIMENTAL HUMAN GINGIVITIS

The purpose of this study was to determine the changes that occur in t he gingival microcirculation during the development of experimental gi ngivitis in humans. There have been no studies published to date combi ning videomicroscopy and laser Doppler flowmetry to study vascular dyn amics in experimental gingivitis. Alterations occurring in the microci rculation of the marginal gingiva in 10 (18-30-year-old), healthy male humans when they suspended oral hygiene procedures in a proscribed ar ea for 12-16 days were monitored. A partial mouth, experimental gingiv itis model was employed. Gingival health was evaluated before and afte r the experimental period by assessing gingival and plaque indices and gingival crevicular fluid volume. Gingival vascular monitoring includ ed measurement of red blood cell velocity in individual gingival micro vessels via videomicroscopy and measurement of regional gingival blood flow using laser doppler flowmetry. The number of vessels visible in a given microscopic field in a given subject and the number of vessels exhibiting flow were also determined from the videotapes. Systemic ca rdiovascular and respiratory parameters were monitored to ensure that gingival vascular changes were not secondary to systemic changes. Ging ivitis developed in all subjects; significant increases (Student t-tes t, p < 0.05) were seen in plaque index, gingival index, bleeding on pr obing and crevicular fluid volume. No change in superficial capillary blood velocity and a significant decrease in gingival regional blood f low were seen with gingivitis. A significant increase in the number of vessels visible in microscopic fields and a decrease in the % of vess els exhibiting flow were observed. Gingival microcirculation exhibited a dramatic, dynamic change in response to the development and progres sion of gingivitis.