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

Objectives
: In vivo toothbrush studies differ widely in design, plaque indices employed, plaque accumulation period, brushing duration and regimen. This study aimed to evaluate plaque removal efficacy of toothbrushes to guide clinical model development.

Methods
: This was a single-centre, randomised, controlled, examiner-blind, method development study in 80 healthy participants. Over 28 days, participants brushed twice-daily (1 min) 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 7- and 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 (p<.0001, RPI/TPI). Toothbrushes A and B showed significant (p<.05) pre-brushing RPI/TPI plaque reductions after 7- and 28-days use versus Day 0 pre-brushing (except Toothbrush B, Day 28, non-significant 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
: All toothbrushes showed plaque-removal efficacy after single-brushing events and small but increasing reductions in pre-brushing plaque levels over 28 days. Similar trends were observed irrespective of the plaque index employed. These data will inform the design of future clinical studies of plaque removal efficacy using manual toothbrushes.

Clinical Significance Statement (50 of 50 words)
: 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 provides useful information for the design of future clinical studies to assess plaque removal efficacy of manual toothbrushes and generate results to inform clinical recommendations.