The effectiveness of manual versus powered toothbrushes for dental health: a systematic review

To compare manual and powered toothbrushes in everyday use, principally in relation to plaque removal and gingival health. Stain, calculus removal, dependability, adverse effects and cost were also considered.

A systematic review was undertaken in collaboration with the Cochrane Oral Health Group. Five electronic databases were searched to identify randomised controlled trials comparing powered and manual toothbrushes. Trials of less than 28 days duration, or where toothbrushing was supervised, were excluded. Assessment of relevance, data extraction and validity assessment were all undertaken independently and in duplicate by two reviewers. Included studies were grouped according to the mode of action of the powered toothbrush. The primary outcomes were plaque and gingival health with data defined as either short-term (1-3 months) or long-term (greater than 3 months) duration were analysed. Powered brushes were categorised into six groups depending on mode of action. Numerical data extracted were checked by a third reviewer for accuracy and entered into RevMan (version 4.1).

The initial search identified 354 studies. Two hundred and fifteen full articles were obtained of which 29 trials fulfilled the inclusion criteria with results, which could be entered in the meta-analysis. Twenty-six trials (1786 participants) reported short-term and 10 trials (798 participants) long-term plaque scores. Twenty-nine trials (2236 participants) reported short-term and 10 trials (798 participants) long-term gingivitis scores. Powered brushes reduced plaque and gingivitis at least as effectively as manual brushing. Rotation oscillation powered brushes statistically significantly reduced plaque and gingivitis in both the short and long-term. For plaque at one to 3 months the standardised mean difference was -0.44 (95% CI: -0.66 to -0.21), for gingivitis SMD -0.45 (95% CI: -0.76, -0.15). These represented an 11% reduction on the Quigley Hein Plaque index and a 6% reduction on the Löe and Silness gingival index. At over 3 months the effects were SMD for plaque -1.15 (95% CI: -2.02, -0.29) and SMD for gingivitis -0.51 (95% CI: -0.76, -0.25). These represented a 7% reduction on the Quigley Hein Plaque Index and a 17% reduction on the Ainamo Bay Bleeding on Probing Gingival Index. Sensitivity analyses revealed the results to be robust when selecting trials of high quality. There was no evidence of any publication bias. No other powered brush designs were consistently superior to manual toothbrushes. In these trials, data on cost, reliability and side effects were inconsistently reported.

In general there was no evidence of a statistically significant difference between powered and manual brushes. However, rotation oscillation powered brushes significantly reduce plaque and gingivitis in both the short and long-term. The clinical significance of this reduction is not known. Observation of methodological guidelines and greater standardisation of design would benefit both future trials and meta-analyses.