The clinical effectiveness of a manual ionic toothbrush in the removal of dental plaque and the reduction of gingivitis was evaluated. A double-blind study evaluated the effect of a small, imperceptible electric current on established dental plaque and gingivitis during toothbrushing. Sixty-four adults completed the study. Gingivitis and plaque scores were determined at baseline and after 3 and 6 months. The baseline indices of the two groups were well balanced. At each examination, the participants were instructed how to hold the toothbrush properly and reminded to change brush heads every 4 weeks. Statistically significant improvements in Löe Gingival Index scores were observed from baseline to 6 months between the control and test groups and within the test group. The Quigley-Hein Plaque Index scores also showed a significant improvement from baseline to 6 months between the control and test groups and within the test group.