Evidence not strong enough to advocate powered toothbrushes over manual for orthodontic patients

Studies were sourced using Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane Library, Institute for Scientific Information proceedings, Cambridge Scientific Abstracts, UMI Proquest, Trials Central (www.trialscentral.org) and the metaregister of controlled trials (www.controlled-trials.coms), along with the references of identified articles. No restrictions were placed on year of publication, publication status or language of the retrieved trials.

Randomised controlled trials were selected that compared powered and manual toothbrushes and involved participants of any age who wore fixed appliances, and which reported outcome measures quantifying gingival inflammation. Cross-over studies with a washout period of at least 1 month between experimental periods were also included. Split-mouth studies and trials involving interventions that combined toothbrushing with the use of antimicrobial mouthrinses, irrigation devices, or interdental cleansing and those of less than 4 weeks\[primes] duration were excluded.

Initial assessment and data abstraction was carried out by two reviewers independently. The quality of the trials was evaluated by assessing randomisation, allocation concealment, blinding of the examiner, description of losses, and the use of intention to treat analyses. Trials were divided into categories depending on the mode of action of the powered toothbrush. The weighted mean difference with 95% confidence intervals was used to express the comparative treatment effect. The random-effects method for meta-analysis was used to combine treatment effects across studies in each category. Heterogeneity was investigated visually, using the I2 test and the Cochran test.

Only five trials were considered appropriate for inclusion in the meta-analysis, and these could be grouped into four categories according to mode of action. None of the studies was of more than 60 days' duration. Based on quality assessment and the short experimental period of these trials, there is currently not sufficient evidence to suggest particular efficacy of powered toothbrushes in reducing gingivitis in people who are undergoing fixed orthodontic appliance therapy.

No conclusions can be drawn on the comparative effectiveness of powered toothbrushes in reducing gingivitis in clinical orthodontic practice. Greater standardisation of the methods used is desirable in future trials.