Diurnal Dynamics in Plaque Regrowth Using a Novel Manual Toothbrush

Objectives: This research evaluated overnight and afternoon plaque regrowth efficacy of a novel manual toothbrush compared to a standard manual toothbrush using Digital Plaque Image Analysis (DPIA).

Methods: This study was a randomized, 3-period crossover design, which examined plaque regrowth of two manual toothbrushes: a) Oral-B Pro-Health^® Clinical Pro-Flex^® (OBPH) and b) ADA flat-trim. Subjects were randomly assigned to one of two treatment sequences and instructed to brush teeth twice a day (morning and evening for 1 min). Each treatment period was 5 days in duration and consisted of Day-1, Day-3 and Day-5 study visits with morning pre-brushing DPIA measurements followed by a supervised on-site product use and a second DPIA measurement taken approximately 5 hours post-brushing. ANCOVA was used to analyze the am/pm plaque regrowth with Day-1-am baseline scores as covariate.

Results: 16 subjects were enrolled (manual toothbrush users from a general adult population) and all of them completed the study. Baseline mean plaque coverage ranged between 13.9% and 14.4% for the two brushes and didn’t differ significantly (p=0.623). At morning of Day-5 the mean pre-brushing plaque was 12.8% for the OBPH and 15.3% for the ADA brush. At the afternoon of the same day, means of 5-hours post-brushing plaque were 11.2% for the OBPH and 14.1% for the ADA brush. Analysis of covariance showed that the OBPH brush had significantly less plaque than the ADA brush at morning of Day-5 (2.5%; p=0.010) and also significantly less plaque in the afternoon of Day-5 (2.9%; p<0.001).

Conclusions: The novel OBPH brush had statistically significantly lower morning pre-brushing plaque and afternoon (5-hours post-brushing) plaque than the ADA brush on Day-5 (after 4 days of brushing, p≤0.01). Both brushes were well tolerated.