Four independent clinical studies were conducted to compare the short- and long-term effectiveness of three commercially available toothbrushes. Two of the four studies compared plaque removal in a single-use, crossover design, and two studies compared plaque and gingivitis reduction efficacy for a long-term, three-month use. The Turesky modification of the Quigley-Hein Plaque Index and the modified Gingival Index were used to assess plaque and gingivitis levels, respectively. The two long-term studies directly compared the Oral-B P-35 and Crest Complete toothbrushes, while the two single-use studies compared the Oral-B P-35, Crest Complete and Colgate Precision toothbrushes. In all four studies, there were no significant differences found between any of the toothbrushes.