The aim of this study was to compare the cleaning efficacy of an experimental toothbrush (GABA International AG) with a standard toothbrush (ADA reference toothbrush) in a controlled, examiner blinded, 48h plaque regrowth splitmouth study. 87 subjects between 18 and 63 years of age (27.3±6.8y) took part in the study. After a 12 day acclimatisation period and 48h of no oral hygiene measures the teeth of the upper right and lower left quadrant were brushed for one minute with either the test or the control toothbrush according to a pre-determined randomisation list followed by cleaning the other two quadrants with the complementary toothbrush, respectively. Immediately before and after tooth brushing plaque was measured by one examiner (E.B.) blinded with respect to the used toothbrushes utilizing the Turesky modification of the Quigley-Hein Plaque Index. Related to all tooth surfaces plaque was reduced by the test toothbrush from 1.95±0.48 to 1.02±0.41 (p Keywords: Filamente, Gingivitisreduktion, Handzahnbürsten, Zahnbürsten