PURPOSE To evaluate the effect of adding a pulsating bristle action to the established oscillating/rotating action of the Braun Oral-B Ultra Plaque Remover (D9) on plaque removal. MATERIALS AND METHODS Plaque removal was evaluated using the modified Quigley-Hein Plaque Index in a double blind randomized, crossover study involving 32 healthy volunteers without any dental training. After 2 weeks use of the D9 during which time subjects received training in its use, subjects abstained from oral hygiene for 48 hours. They were then assessed for plaque after which they brushed their teeth using an experimental toothbrush randomly set to either the D9 oscillating/rotating action or to the new 3D action with an additional pulsating movement of the brush head in the direction of the long axis of the bristles. After brushing, plaque was again evaluated. Following a further 2 weeks of normal home use of the D9, subjects returned and the procedure was repeated using the brush set in the second mode. RESULTS Both toothbrush actions were found to be effective at removing plaque from all sites and surfaces in the mouth. The 3D action was consistently more effective than that of the D9, the difference being statistically significant for the whole mouth, the upper jaw, the lingual surfaces and for all interproximal sites, in particular in the upper jaw.