 The study was a single-blind, randomized clinical timer study consisting of four identical experiments testing each brush in one quadrant. The distribution of the quadrants and brushes was randomized so that always all brushes were used within one participant. The teeth were brushed by a dental hygienist for 10, 20, 30, 45, 60 und 90 seconds per quadrant. No toothpaste was used throughout this study. The plaque assessment Tureskey modified QHI was done after each time interval blinded on six sites per tooth by a separate investigator. Ninety subjects participated in the study and received a professional prophylaxis prior to the experiment. They were requested to refrain from brushing their teeth for 48 hours prior to the experiment. 