Purpose: To assess the benefit of the power component of two power toothbrushes, with sonic and rotation-oscillation mechanisms, on plaque removal efficacy.
Methods: Two independent studies with identical designs were used to assess the benefit of the power component of two power toothbrushes, with sonic and rotation-oscillation mechanisms, on plaque removal efficacy. Each brush was tested with the power 'On' relative to a control of the same brush with the power 'Off' used like a manual toothbrush. The studies were carried out independently at different sites, and each employed a replicate use, single brushing, two-treatment, four-period, examiner-blind, randomized, crossover design for assessing plaque removal. Study 1 compared rotation-oscillation action (Oral-B Triumph with FlossAction brush head), and Study 2 compared sonic action (Sonicare FlexCare with ProResults standard brush head) with power on versus off. The two treatments in each study consisted of (1) brushing teeth per manufacturer's instructions of the power toothbrush and (2) brushing without power by using the power toothbrush like a manual toothbrush. Prior to the treatment phase of each study, subjects exclusively used the assigned study toothbrush for 2 minutes twice per day according to the manufacturer's instructions (power on) during an acclimation period. Plaque was scored at prebrushing (baseline) and post-brushing on Visits 2, 3, 4 and 5 using the Turesky Modified Quigley-Hein Plaque Index (TMQHPI). A 2-day washout period separated each treatment period.
Results: 32 subjects were enrolled in each study; 28 subjects provided complete data for Study 1 and 32 subjects provided complete data for Study 2. The adjusted mean TMQHPI plaque removal scores for Study 1 were 0.793 for the rotation-oscillation 'On' regimen and 0.675 for the rotation-oscillation 'Off' regimen. This represents a statistically significantly (P<0.0001) greater plaque score reduction for the rotation-oscillation 'On' versus rotation-oscillation 'Off' treatment. The adjusted mean TMQHPI plaque removal scores for Study 2 were 1.042 for the sonic 'On' regimen and 1.007 for the sonic 'Off' regimen. This represents a nonsignificant (P=0.426) greater plaque score reduction for the difference between sonic 'On' versus sonic 'Off' regimen.