The bleeding/plaque ratio in the treatment of periodontal disease.

The bleeding/plaque ratio has been suggested as a means of assessing susceptibility to periodontal disease, and as a prognosticator of periodontal breakdown. In this study, 100 males and 131 females were evaluated by means of the bleeding/plaque ratio to make a prognosis of the outcome of periodontal therapy. Initial plaque and gingival bleeding scores were used to calculate the bleeding/plaque of the subjects, and these ratios were compared with the resolution in the clinical parameters of plaque, gingival bleeding and severe and moderate pocketing. The subjects were divided into those showing higher bleeding incidence and lower bleeding incidence as assessed by post-treatment gingival bleeding. The bleeding/plaque ratios for the 2 groups were not significantly different, and therefore could not be used clinically for assessment of susceptibility to, or for prognostication of periodontal breakdown. 4 subjects were randomly selected from these 2 groups, and their data used to illustrate the limitations of the bleeding/plaque ratio. The bleeding/plaque ratios bore no relationship to the response to treatment in these 8 individuals, when evaluated in terms of reduction in plaque levels, gingival bleeding or pocketing. It is therefore concluded that the bleeding/plaque ratio in its present form is not of clinical value for making a prognosis of the likely outcome of treatment, and some suggestions as to how it may be improved are made.