Purpose: A systematic review examining the clinical effectiveness of power versus manual toothbrushes was conducted by the Cochrane Collaborations Oral Health Group. Their review examined clinical trials conducted through 2001 and used international standards to identify, access, evaluate, analyze, and report the data. Part I of this series discussed distinguishing characteristics of evidence-based publications, such as systematic reviews, whereas this report provides a summary of the Cochrane Review, its importance to the profession, and discusses the strengths and limitations of systematic reviews.
Methods: Search strategies to identify published clinical trials on power toothbrushes were developed, and manufacturers were contacted for additional published and unpublished information. Trials were selected based on pre-established criteria; including whether they compared power versus manual toothbrushes used a randomized research design tested products in the general population without disabilities, provided data on plaque and gingivitis, and were at least 28 days in length. Six reviewers independently extracted information in duplicate. Indices for plaque and gingivitis levels were expressed as standardized mean differences for data distillation. Data distillation was accomplished using a meta-analysis, with a mean difference between power and manual toothbrushes as the measure of effectiveness.
Results: Searches identified 354 trials, of which 29 met inclusion criteria. These trials involved 2.547 participants who provided data for meta-analysis. Results indicated that for both plaque and gingivitis, all types of power toothbrushes worked as well as manual toothbrushes, however only the rotating oscillating toothbrush consistently provided a statistically significant though modest benefit over manual toothbrushes in reducing plaque (7%) and gingivitis (17%). None of the battery powered toothbrush studies met the inclusion criteria.
Conclusion: The Cochrane systematic review used international standards to examine more than 30 years of published studies. A concern is that only one type of electric toothbrush, the rotating oscillating toothbrush consistently demonstrated a statistically significant benefit over manual toothbrushes, and the majority of studies did not meet the standards for inclusion in moving forward it will be important to conduct methodologically sound studies demonstrating the ability of power toothbrushes to reduce the incidence and prevalence of caries and periodontal disease.