Plaque disclosing agent as a guide in biofilm removal in patients with fixed orthodontic appliance: a randomized clinical trial

Effective professional plaque removal is of major importance in the prevention of white spot lesions and gingivitis in patients with fixed orthodontic appliances. However, visual identification of plaque can be difficult, especially around brackets, ligatures and wires. The purpose of the present randomized clinical trial was to evaluate the effectiveness of a plaque disclosing agent (PDA) as a visual guide for biofilm removal. Thirty-two systematically and periodontally healthy adults with fixed orthodontic appliances and Plaque Index (PI) > = 25% were enrolled from October 2020 to May 2022, the subjects were equally randomized into test and control group. Primary outcome was the change in the difference in percentage of residual plaque area (RPA) between the two study groups. In the test group, a PDA was applied before professional oral hygiene, whilst the control group received a hygiene session without disclosing. The PDA was then re-applied at the end of the treatment in both groups, and the RPA was assessed via Image-J software analysis of standardized frontal photos and compared between groups. The average RPA in the test group was 3.9% (CI 95% 2.6%; 5.1%), which resulted significantly lower than in the control group, where it reached 12.0% (CI 95% 8.0%–16.0%) (p-value < 0.001). The percentage of area with residual plaque was modelled using a beta-regression model. The use of plaque disclosing agents as guidance for professional oral hygiene treatment leads to improved plaque removal in patients with fixed orthodontic appliances. NCT05428189, 2022-06-08, retrospectively registered.