In-vivo and In-vitro Plaque Removal Efficacy of two Brush Heads

Objectives: The aim of this research was to comparatively evaluate the performance of two different brush heads for oscillation-rotation toothbrushes via an in-vitro robot study and a randomized clinical trial.

Methods: In-vitro performance was analyzed via a six-axes industry robot simulating tooth brushing on dental models (n=6, cross-over) covered with plaque substitute (PS) via controlled and standardized brushing time, motions and force. Differences of remaining PS were analyzed using a single-sided paired t-test.

In-vivo performance was evaluated in a randomized, 2-treatment, 4-period cross-over design examining single-use plaque removal of Oral-B Precision Clean (OBPC) vs. Dr. Best Interdental (DRBZZ), both on an Oral-B Professional Care 1000 (D20) handle. 28 subjects with evidence of overnight plaque were randomized to one of four treatment sequences. Plaque was scored before (baseline) and after brushing using extended Turesky Modified Quigley-Hein Index (TMQH). ANCOVA was used to analyze the post-brushing plaque with baseline scores as covariate.

Results: Both in-vitro and in-vivo clinical studies showed significantly higher plaque reduction of OBPC vs. DRBZZ. The in-vitro study revealed a significant relative difference of whole mouth PS reduction of 6.5% (p=0.009; 71.8% vs. 67.4%) and a directional advantage of 2.2% (p=0.14) in approximal regions. Baseline mean TMQH scores in the clinical study ranged between 2.632 and 2.675 for both brushes and didn’t differ significantly (p=0.64 whole mouth, p=0.755 approximal). Adjusted mean TMQH reductions were 1.492 for OBPC vs. 1.389 for DRBZZ (whole mouth), and 1.428 for OBPC vs. 1.309 for DRBZZ (approximal). This corresponds to significant relative differences of 7.4% (p<0.001) for whole mouth and 9.0% (p<0.001) in approximal regions.

Conclusions: The OBPC brush removed statistically more plaque compared to the DRBZZ brush, both in whole mouth and in approximal regions. Results were confirmed in-vitro by a significant difference for whole mouth and a directional advantage in approximal regions.