Gingival bleeding on brushing as a sentinel sign of gingival inflammation: A diagnostic accuracy trial for the discrimination of periodontal health and disease.

Aim: To assess the accuracy of self-reported gingival bleeding on brushing (GBoB) for differentiating between periodontal health and disease and explore the optimal haemoglobin concentration that enables visual detection of GBoB.

Materials And Methods: Self-assessment of GBoB was conducted in supervised sessions for 408 consecutive adults. The haemoglobin levels in saliva/toothpaste slurry (TPS) were analysed, followed by a full-mouth periodontal examination. Periodontal diagnoses were made based on the 2017 classification of periodontal diseases. Gingival inflammation was defined as presence of at least 10% of sites with bleeding on probing (BOP). Logistic regression and area under the receiver operating characteristic curve (AUROC) analyses were applied to assess the accuracy of GBoB.

Results: Overall, 37.1% of the subjects claimed self-reported GBoB, and they had higher values of BOP (median: 25.0%; interquartile range (IQR): 16.0%-37.5%) than those without GBoB (median: 13.5%; IQR: 8.0%-24.8%, p < .001). The concentration/total amount of haemoglobin in TPS was positively correlated with the number of bleeding sites (r = .409/r = .520, p < .001). Haemoglobin concentration of 90.58 μg/ml or 0.51 μl blood volume enabled visual detection of GBoB with an AUROC of 0.848. Self-reported GBoB exhibited significantly increased values of diagnostic odds ratios (3-8) for varying degrees of gingival inflammation and periodontal disease (gingivitis and periodontitis). It showed low to moderate accuracy for discriminating periodontitis and gingivitis from periodontal health, with a sensitivity of 37.1% and 61.3% and a specificity of 84.8% and 84.4%, respectively. Absence of self-reported GBoB and low levels of haemoglobin had 93%-98% predictive values for periodontal health.

Conclusions: Despite its low sensitivity for the discrimination of periodontitis, self-reported GBoB is a promising sentinel sign for periodontal health and disease, and gingival inflammation in particular. It is visually detectable after minor blood loss. After validation in an independent population, identification of GBoB may promote earlier detection and better prevention and treatment of periodontal disease, thereby eventually reducing the global burden of the disease.