Brushing without brushing?—a review of the efficacy of powered toothbrushes in noncontact biofilm removal

Objectives: The aim of the present review was to analyze the impact of the hydrodynamic effects created by powered toothbrushes on biofilm removal in vitro. Materials and methods: A MEDLINE search was performed for publications published by 20 May 2012; this search was complemented by a manual search. The study selection, data preparation, and validity assessment were conducted by two reviewers. Results: Sixteen studies were included. The studies differed with respect to the methods of biofilm formation and brushing protocols. Eighteen different powered toothbrush models were evaluated. Toothbrushes with side-to-side action demonstrated biofilm removal without direct bristle contact to biofilms ranging from 38 to 99%. Most studies found biofilm removal exceeding 50%. Biofilm reduction using multidimensional toothbrushes was significantly lower than by those with the side-to-side mode. Detachment forces due to hydrodynamic phenomena, passing air-liquid interfaces, and acoustic energy transfer were suggested to cause reduction of the biofilm. Conclusion: Noncontact biofilm reduction was obtained by the hydrodynamic effects of some powered toothbrushes in vitro. Clinical relevance: Powered toothbrushes may have the potential to simplify self-performed oral hygiene. However, additional beneficial effects of higher amounts of noncontact biofilm removal in vitro have not been shown clinically, yet