Plaque and Gingivitis Control

One reason first generation electric toothbrushes were not widely promoted beyond special needs and orthodontic populations in the 1960s and 1970s was a lack of evidence that they provided equivalent or superior plaque control to a standard manual toothbrush. In 1985, an international oral hygiene workshop convened and reviewed the comparative effectiveness of available power toothbrushes. Oscillating-rotating power brushes had not been launched, and the reviewers determined that the while power toothbrushes aided in plaque removal, there was not yet conclusive evidence that either manual toothbrushes or power toothbrushes were superior to one another.20 By the late 1990s, following the introduction of additional power brushing technologies (including oscillating-rotating and sonic), the opinion of international thought leaders had evolved. During the 1998 European Workshop on Mechanical Plaque Control, Dr. G.A. van der Weijden, (ACTA, Amsterdam), concluded, “Clinical trials over the past 10 years show that in controlled trials electric toothbrushes appear to be superior to manual brushing.”21

A very large systematic review (considered the gold standard in evaluating randomized controlled trials’ effectiveness data) of the literature to date comparing the relative effectiveness of power and manual toothbrushes was undertaken by the independent and well-respected Cochrane Collaboration in 2003 (updated in 2005).6 The review encompassed 42 clinical trials involving almost 4,000 subjects, and assessed effectiveness outcomes in the removal of plaque, the health of the gingiva, stain, calculus, dependability, adverse effects and costs. The review concluded that only power toothbrushes which employed a rotation-oscillation action were proven consistently superior at removing plaque and reducing gingivitis more effectively than manual brushes in the short and long term. In 2014 the Cochrane Collaboration once again concluded that oscillating-rotating technology – such as is used in Oral-B power toothbrushes – is the only type of power brush consistently proven to reduce more plaque and gingivitis versus manual brushing in the short and long term. This outcome was derived from a larger study that concluded power brushes outperform manual tooth brushing.22 In a recent example, a 4-week clinical investigation by Klukowska and colleagues wherein 118 subjects were assigned to either an oscillating-rotating toothbrush or a standard manual brush found that the power toothbrush yielded significantly superior reductions in gingivitis (by almost three times) and bleeding and plaque (by almost two times) compared to the manual brush.23

Additional research since the Cochrane review has further expanded the body of literature supporting power toothbrushes’ ability to fight plaque and gingivitis. Sonic-powered brushes (e.g., Sonicare) have been reported to provide statistically significant plaque and/or gingivitis reduction versus baseline in published reports.24,25 However, a 2011 Cochrane review of seven trials in clinical trials of up to three months durations concluded there was evidence that rotation-oscillation power toothbrushes reduced plaque and gingivitis more than side-to-side (sonic) power brushes.26 In an 8-week clinical trial of subjects with pre-existing gingivitis and plaque, those brushing with an entry level oscillating-rotating-pulsating toothbrush had 28%, 35% and 36% significantly less plaque, gingivitis, and bleeding, respectively, than subjects assigned to a leading sonic technology toothbrush.27 Recently a 6 week clinical was published which demonstrated that a sonic toothbrush was statistically superior to an oscillating-rotating-pulsating toothbrush in reducing gingival inflammation, gingival bleeding, and supragingival plaque following 2 and 6 weeks of home use.28

In considering the value-oriented battery-powered toothbrushes, effectiveness can vary by brand/mode of action, but some have been shown in controlled clinical investigations to be more efficacious in plaque removal and gingivitis reduction than comparator toothbrushes. For example, in one published clinical trial, the Oral-B Battery Toothbrush (D4) provided 14% greater whole mouth plaque removal relative to a manual brush control,29 and in another investigation, yielded significantly greater plaque reduction than another marketed battery-powered brush, while concurrently providing improvement in gingival bleeding.30 Similarly, the SpinBrush™ (Arm & Hammer) battery-powered toothbrush was shown in four crossover-design clinical trials to provide 10%-40% superior plaque removal relative to various manual toothbrush controls.31