Quantification of gingival edema using a new 3-D laser scanning method

The aim of the study was to investigate the suitability of measuring volume differences in the gingival tissue for monitoring changes in the inflammatory status of the gingiva.

Data for this investigation were obtained from a mouthrinse evaluation which was performed as a 4-week, double-blind, placebo-controlled, cross-over study in which localised experimental gingivitis was induced. 24 volunteers were enrolled in the study. Only the data from the placebo period of each subject were used in the current investigation. During the plaque accumulation periods, plaque guards were worn during routine performance of oral hygiene measures to prevent any plaque removal from the experimental area (1st and 2nd premolars and molars in one upper quadrant). Clinical examinations with assessment of plaque and gingivitis were performed on days 0, 4, 7, 14, 21, 28 and 42. Volume differences in the gingival papillae were determined between day 0 and days 21, 28, and 42, and between days 28 and 42 by taking measurements from replicas of the respective clinical situations using a 3-D laser scanner and reference-free automated 3-D superimposition software. Data were analysed with the Wilcoxon signed ranks test.

Plaque accumulation in the experimental area resulted in a highly significant increase (p<0.001) of inflammation of the gingival papillae. The mean (standard deviation) papillary GI at baseline was 0.23 (0.34) as compared to 1.22 (0.27) and 1.2 (0.31) on days 21 and 28, respectively. The mean increase in volume of all papillae as compared to baseline was 25,478 micrometer3 after 21 days and 24,210 micrometer3 after 28 days. After resuming a normal oral hygiene regimen, mean volume of the papillae decreased between days 28 and 42 by 19,250 micrometer3.

With this novel method, gingival papillary edema can be quantified in vivo from replicas of the clinical situation.