Abstract：The purpose of this study was to evaluate the plaque removal effects of an electric interdental toothbrush and a conventional manual interdental toothbrush at the proximal surfaces of model teeth. The electric interdental toothbrush was composed of a main body with a motor that generated the vibrations and a PROSPEC ® interdental toothbrush attachment. The manual interdental toothbrush did not vibrate. The mean plaque removal rate of the electric interdental toothbrush was 26％ and 32％ after 5 and 10 cleanings, respectively, and these removal rates were significantly higher(p＜0.01)than those for the manual interdental toothbrush. Based on these findings, it is concluded that the plaque removal effect of the electric interdental toothbrush was greater than that of the manual interdental toothbrush.

Abstract： The aim of this study was to evaluate the plaque removal efficacy of three tooth brushes：the Philips Sonicare Diamond Clean with a medium brush head, Philips Sonicare Diamond Clean with a mini brush head, and the Philips Sonicare Flexcare with a medium brush head. This study was an investigator-blinded, three-brush crossover design study. Twenty dentists with clinically healthy gingiva and without restorative materials or prosthetic teeth participated in this study. Prior to the experiment, the subjects received a professional prophylactic program and were requested to refrain from brushing their teeth for 48 hours. Assessment was carried out using the modified OʼLearyʼs plaque control record (6 sites per tooth) at the baseline and after each brushing interval by one blinded investigator. The PCR score was 100% at the baseline in all subjects. The results showed no statistically significant differences in the PCR score among the three tooth 140