Randomised methodology development study to investigate plaque removal efficacy of manual toothbrushes

Objectives: This study aimed to evaluate plaque removal efficacy of toothbrushes to guide clinical model development. Methods: This single-centre, randomised, controlled, examiner-blind, method development study included 80 healthy participants. Over 28 days, participants brushed twice-daily using a fluoride toothpaste and one of four marketed toothbrushes: Toothbrushes A (compact head) and B (regular head): medium-hard; flat trim; end rounded bristles; Toothbrush C: medium-hard; end-rounded bristles; silky, tapered filaments; compact head; Toothbrush D: soft; tapered filaments; compact head. Supra-gingival plaque removal was evaluated immediately after single brushing events (Days 0, 7, 28, at study centre) and following 7and 28-days' home use via Rustogi modified Navy Plaque Index (RPI) and Turesky modified Quigley Hein Plaque Index (TPI). Results: All toothbrushes provided significant plaque removal after single-brushing events with change from Day 0 pre-brushing scores on RPI ranging from-0.10 to-0.16 (p<.0001) and on TPI ranging from-0.61 to-0.89 (p<.0001). Toothbrushes A and B showed significant (p<.05) pre-brushing RPI/TPI plaque reductions after 7(-0.04/-0.06, respectively for RPI;-0.16/-0.20, respectively for TPI) and 28-days (-0.04/-0.03, respectively for RPI;-0.20/-0.11, respectively for TPI) use versus Day 0 pre-brushing (except Toothbrush B, Day 28, nonsignificant TPI). There were no significant differences with Toothbrush C. Toothbrush D TPI was significantly lower at both timepoints versus Day 0 pre-brushing (p<.05). Study toothbrushes were generally well-tolerated. Conclusion: The observations from this study showed how various aspects of a study design could impact toothbrushes performance. These data will inform the design of future clinical studies of plaque removal efficacy using manual toothbrushes. Clinical Significance Statement: Regular effective oral hygiene can help prevent and treat gingivitis, principally via twice-daily mechanical cleaning with a toothbrush. Data generated from this methodology development study will help to identify the key aspects which impact toothbrushes' performance and understand which one would be more suitable to answer questions of scientific interest. This study provides useful information for the design of future clinical trials to assess plaque removal efficacy of manual toothbrushes and generate results to inform clinical recommendations.