Relationship between periodontal probing velocity and gingival inflammation in human subjects

Abstract Little is known about the biophysical characteristics of the dentogingival junction in response to the development or resolution of inflammation. The Toronto Automated Periodontal Probe (TAPP) provides an estimate of the integrity of the dentogingival junction by measuring intrapocket probing velocity. The aim of this study was to measure changes of probing velocity in inflamed human periodontium before and after subgingival debridement. 32 subjects exhibiting gingival inflammation were selected; 29 completed the study. Gingival index (GI), plaque index (PLI), bleeding index (BI) and the rate of gingival crevicular fluid flow (CFF) were measured as concomitant variables. The experimental group (N= 16) received scaling, root planing and oral hygiene instruction at baseline. The control group (N=13) received no treatment until after 28 days. Subjects were seen at baseline, day 14, 21 and 28 for measurement of probing velocity and concomitant variables on 6 index teeth. At day 28, the control group was treated and then reassessed 28 days later. The experimental group showed a reduction of 51.6% for mean crevicular fluid flow (p<0.0001), 79.7% for mean plaque index (p<0.0001), 58.0% for mean gingival index (p<0.0001), and 72.0% for mean bleeding index (p<0.002) at day 28, confirming that inflammation was reduced compared with baseline. No significant changes were observed in the control group until after treatment. The velocity of probing and the formation of a plateau in the velocity profile were recorded. The experimental group demonstrated a significant increase (p<0.002) in the frequency of plateau formation and a decrease in mean slope between baseline and day 28 (p<0.02). No significant change was observed in the control until day 56, 28 days after treatment. These data indicate a direct relationship between improved clinical health and increased resistance to probe penetration near the base of the pocket, as reflected by the increased frequency of plateau formation and decreased slope for the terminal segment of the velocity profile curve.