A comparative study of plaque removing efficiency using rotary electric and manual toothbrushes

Plaque removing efficiency was compared between rotary electric and manual toothbrushes. The first part of the study included 19 dental hygiene students randomly assigned to a "rotary" or a "manual" brushing group. The subjects were instructed to brush their teeth three minutes twice a day for three weeks either with rotary electric or with manual brushes. Then for another period of three weeks brushing techniques were reversed. The results showed that the median plaque index for all sites and for buccal and lingual sites was significantly lower in the rotary brushing group (28% vs 39% and 3% vs 6%, p less than 0.05). During the second part of the study 10 of the students refrained from all oral hygiene procedures for four weeks in the anterior mandibular region, i.e. from 33 to 43. They were then randomly assigned to a "rotary" or a "manual" brushing group. Registrations of accumulated plaque were made from photographs at baseline and after 15, 30 and 60 seconds of brushing. ANOVA analysis of the plaque scores showed a significant difference in reduction of plaque in favour of the rotary electric brush (p less than 0.01). The results suggest that the rotary electric toothbrush removes plaque more efficiently than the conventional manual toothbrush.