Bristle splaying and its effect on pre-existing gingival recession-a 12-month randomized controlled trial.

OBJECTIVE: The link between bristle splaying and gingival recession is unclear. METHODS: In a 12-month, parallel group, randomized, controlled clinical trial, 110 systemically healthy participants with pre-existing gingival recessions (pre-GR) were assigned to brush their teeth with either a manual (MT) or a powered toothbrush (PT). Every 3 months, toothbrushes and brush heads were replaced. Wear was measured using the Bristle-Splaying-Index (BSI), matched between groups and correlated to the change of pre-GR. RESULTS: Data from 109 subjects (PT, 55; MT, 54) were analyzed. The overall mean BSI was found to be significantly lower (p < 0.001) in the PT group (median 5.5; second and third quartile 1.9-10.0) as compared to the MT group (21.5; 15.0-30.5). After 12 months, pre-GR decreased significantly in the PT group (∆0.2 +/- 0.1 mm; p < 0.001) and remained stable in the MT group (∆0.1 +/- 0.1 mm; p > 0.05). In the MT group, higher BSI values were associated with a higher risk for increasing or stable recession over 12 months: odds ratio (95 % CI) = 27.9 (1.7; 452.9); p = 0.019. CONCLUSION: After a mean using time of 3 months, the PT group demonstrated a lower BSI than the MT group, and the greater bristle splaying was associated with a higher risk of increased (or stable) GR in subjects using a MT but not a PT. CLINICAL RELEVANCE: Compared to a manual toothbrush, powered toothbrushes seem to be utilized with less force and can be considered safe to use in patients with pre-existing gingival recession.