Patients undergoing orthodontic treatment with fixed appliances are at risk of developing carious white spot lesions and gingival inflammation because of the challenge of oral hygiene. The purpose of this study was to evaluate under home conditions the effectiveness of three different types of electric toothbrushes during active appliance therapy: Interplak (Bausch & Lomb, Berlin, Germany), Rota-dent (Rota-dent, Kusnacht, Switzerland), and Braun Oral-B Plaque Remover (Braun/Oral-B, Kronberg, Germany). A manual technique, which included normal toothbrush, interdental brush, and dental floss, served as reference. The study was structured as a single-blind "Latin square design" study. Thirty-eight orthodontic patients were randomly allocated to groups who, within the test period, alternately used the toothbrushes. Before getting a new toothbrush that was to be used for a period of 4 weeks, each patient received video and written instructions. For another 4 weeks, the patient returned to the usual oral hygiene procedures before receiving the next new toothbrush. Oral hygiene was evaluated at the start of a new test period and after 2 and 4 weeks. Clinical scores included a modified O'Leary Plaque Index and Ainamo Gingival Bleeding Index. Wilcoxon rank testing for aggregated surfaces revealed statistically significantly lower plaque scores for Rota-dent than for the manual technique (p < 0.01). For all other toothbrushes, no differences were found in comparison to the manual technique. For Plaque Indices of specific sites, statistical analysis revealed all electric toothbrushes to be equal to the manual technique. No differences in Gingival Bleeding Indices were found after 4 weeks with either toothbrush. Patients with poor oral hygiene who used Rota-dent and Braun Oral-B Plaque Remover OD5 had statistically significantly lower plaque scores compared with the manual technique (p < 0.01; p < 0.05); for patients with good oral hygiene, these differences were neutralized. It may be concluded that electric toothbrushes of the new generation are a real alternative to the often laborious manual tooth cleaning procedures used during active appliance therapy. Patients with poor oral hygiene may benefit from them especially because plaque removal can be achieved easier and faster.