Review of power toothbrushes considers safety issues
by Shelly L. Campbell, RDH, MPH
The cabbage soup diet. NASA-inspired space food sticks. The belt massager machine to “jiggle away the pounds.” How are these things connected? These health and fitness offerings from the 1960s quickly faded from the public eye after failing to live up to their hype, or by causing safety concerns.
Another health improvement introduction in the ’60s – the electric toothbrush – could have met a similar fate because early prototypes were bulky, unreliable, and even capable of causing electric shock. But unlike other inventors of health fads destined for obscurity, undaunted electric toothbrush manufacturers continued to evolve more streamlined and technologically advanced power toothbrush models over the next several decades.
Today, many children and adults have permanently replaced their manual brush with an electric model, having been won over by the electric brush’s reliable cleaning efficiency and ease of use. Value-based battery brushes, as well as premium multifeature rechargeable electric toothbrushes (also referred to as power toothbrushes), are now mainstream, their popularity reflected in exponential growth over the last decade.1 Interestingly, a recent survey showed only 14% of women surveyed would consider giving up their power brush as a budget-saving sacrifice.2 It’s safe to say that power brushes are here to stay.
Dental professionals see improvements in the oral hygiene and gingival health of patients who use power toothbrushes, both anecdotally and in large surveys.3,4 Additionally, clinical research over several decades has shown that in general, power brushes provide noticeable plaque removal benefits, with one brush technology — oscillating-rotating (O-R) — standing apart when statisticians crunch the numbers to analyze the results of the clinical research.5,6,7 In 2005, the well-respected international Cochrane Collaboration Oral Health Group published a review of 42 of these published clinical investigations, where power toothbrushes, including those with counter-rotational (e.g., Interplak®), oscillating-rotating (e.g., Braun/Oral-B®), and side-to-side (e.g., Sonicare®) modes of action, were directly compared to manual toothbrushes for clinical effectiveness in thousands of patients. From their systematic review and meta-analysis [see Systematic analysis in a nutshell], the Cochrane Group concluded that one brush type produced statistically significantly superior benefits: “Powered toothbrushes with a rotation oscillation action reduce plaque and gingivitis more than manual toothbrushing.”7
The safety question
Power toothbrush effectiveness is seldom debated, but are safety concerns involved? Could the documented connection between power toothbrushing and greater patient compliance8-11 lead to more gingival abrasion caused by longer brushing times or increased brushing frequency? Does power toothbrushing result in more hard tissue wear compared to manual brushing? Will enthusiastic power brush users apply too much force and compromise their gingival tissues or promote recession?
Although the Cochrane review didn’t evaluate safety as the primary objective, it did state, “Any reported side effects were localized and temporary.”7 Other studies and literature reviews have generally come to the same conclusion.12-14 Case closed. Or is it? Lingering questions about the safety of power brushes on hard and soft tissues have persisted in some quarters.15 Hygienists and dentists know their patients take their professional product recommendations seriously, and they want to ensure they’re suggesting the most effective and safe oral commercial products and regimens.
The goal should be evidence-based recommendations as opposed to speculation, but keeping up with all of the literature and assessing the quality and relevance of each individual power toothbrush study requires a significant commitment of time and effort for professionals who already have a lot on their plates.
In search of an answer
Systematic reviews of health topics (see sidebar) can be a great asset to busy professionals who don’t have time to comb through the literature themselves. To address the power toothbrush safety question, a recently published systematic review in the Journal of Periodontology considered theoretical safety concerns about power versus manual toothbrushes through a comprehensive analysis of all relevant published reports. The article is “Safety of Oscillating-Rotating Powered Brushes Compared to Manual Toothbrushes: A Systematic Review” by Van Der Weijden et al.16
Here are the key findings:
What research was included?
O-R power toothbrush safety research was chosen for comparison to manual toothbrushes based on the Cochrane findings.7 All published English language titles and abstracts through May 2010 were included in a full search of three major databases (e.g., PubMed-Medline), resulting in 899 potential publications that were evaluated, with 35 meeting all predetermined eligibility criteria. The 35 studies in the final review were designed to measure soft and/or hard tissue safety by tracking either primary (gingival recession) or secondary parameters (observed or reported adverse events or hard tissue effects), or a surrogate parameter (stained gingival abrasion or brushing force).
What patients and toothbrushes were involved?
There was considerable diversity among the nearly 2,000 patients included in the 31 randomized and blinded human subject clinical trials, which ranged from four days to three years. These included adults with and without elevated plaque, gingivitis and/or bleeding, children with and without orthodontia, and periodontal patients. Braun/Oral-B or Philips/Jordan manufactured the power brushes in the reviewed studies, while 10 various comparator manual brushes were also represented. The majority of toothbrushing was unsupervised in the home setting.
Were O-R power toothbrushes associated with more gingival recession?
No. A meta-analysis [see sidebar] of two six-month clinical trials focusing exclusively on gingival recession showed there were no significant recession differences between the power and manual toothbrush groups.
Did O-R power brushes use more force than manual brushes?
No. In the two force investigations, the average O-R power brush brushing force was significantly lower than the average manual toothbrush brushing force.
Was there more gingival abrasion with use of the O-R power toothbrushes?
Gingival abrasions that could potentially be caused by toothbrushing were found in both the manual and O-R power toothbrush groups, but the authors of the published reports described them as either negligible/not clinically significant, or occurring with about the same frequency in the manual and power brush groups, and not significantly different when statistically tested.
How important is in vitro data? Did the in vitro studies show greater wear with O-R brushes?
Since there is currently no standard methodology with enough sensitivity for long-term clinical assessment of hard tissue brushing damage, in vitro studies are a valuable step in identifying potential safety concerns (like abrasion potential) that are challenging to discover clinically.
Four in vitro (laboratory) investigations met eligibility criteria and were included in the review. The three trials evaluating human dentin found similar or less wear with use of the O-R power toothbrushes, compared with manual brushes used under simulated clinical conditions. The authors of the fourth study suggested that bovine enamel loss after an acidic attack may be increased with use of certain power brushes when used at the same brushing force. But understanding the clinical implications is difficult, given that toothbrushing forces have been shown to be significantly higher when manual brushes are used.
What’s the bottom line?
Oscillating-rotating power toothbrushes were not shown to have a greater safety risk when compared head-to-head with manual brushes. The review authors concluded that, “This systematic review of a large body of published research in the preceding two decades consistently showed oscillating-rotating toothbrushes to be safe when compared with manual brushes, and collectively indicated that they do not pose a clinically relevant concern to either hard or soft tissues.”
Want to read more or want to see the detail for all tables, figures, and the meta-analyses? The abstract of the publication, “Safety of Oscillating-Rotating Powered Brushes Compared to Manual Toothbrushes: A Systematic Review”16 is available online at http://www.joponline.org/doi/abs/10.1902/jop.2010.100393, as is the full text for subscribers. You can find the full print version at your local health sciences library.
Shelley L. Campbell, RDH, MPH, of Teneriffe Research Associates, has worked in the oral health clinic research field for over 20 years. She writes from her home in Lee’s Summit, Mo., and occasionally does medical writing for Procter & Gamble.
1. Power brush sales whirring as prices drop. Chain Drug Review. Available at: http://findarticles.com/p/articles/mi_hb3007/is_3_31/ai_n31357545/. Accessed 15 April 2011.
2. “Toothbrush effect” helps Brits smile through the recession. PR Newswire Europe Ltd. Available at: http://www.prnewswire.co.uk/cgi/news/release?id=257225 Accessed 15 April 2011.
3. Warren PR, Landmann H, Chater BV. Electric toothbrush use. Attitudes and experience among dental practitioners in Germany. Am J Dent 1998:Sep;11(Spec No):S3-6.
4. Warren PR, Ray TS, Cugini M, Chater BV. A practice-based study of a power toothbrush: assessment of effectiveness and acceptance. J Am Dent Assoc 2000;Mar;131(3):389-94.
5. Van der Weijden GA, Timmerman MF, Danser MM, van der Velden U. The role of electric toothbrushes – advantages and limitations of electric toothbrushes. In: Lang NP, Attström R, Löe H, eds, Proceedings European Workshop on Mechanical Plaque Control, Berlin: Quintessence Publishing; 1998a.: pgs. 138-155.
6. Sicilia A, Arregui I, Gallego M, et al. A systematic review of powered vs manual toothbrushes in periodontal cause-related therapy. J Clin Periodontol 2002;29 Suppl 3:39-54; discussion 90-1.
7. Robinson P, Deacon SA, Deery C, et al. Manual versus powered toothbrushing for oral health. Cochrane Database of Systematic Reviews 2005, Issue 2. Art. No.: CD002281. DOI: 10.1002/14651858.CD002281.pub2.
8. Walters PA, Cugini M, Biesbrock AR, Warren PR. A novel oscillating-rotating power toothbrush with SmartGuide: designed for enhanced performance and compliance. J Contemp Dent Pract 2007;8:1-9.
9. Stålnacke K, Söderfeldt B, Sjödin B. Compliance in use of electric toothbrushes. Acta Odontol Scand 1995;53:17-19.
10. Van der Weijden FA, Timmerman MF, Piscaer M, et al. A comparison of the efficacy of a novel electric toothbrush and a manual toothbrush in the treatment of gingivitis. Am J Dent 1998;11(Spec No):S23-28.
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12. Heasman PA, McCracken GI. Clinical evidence for the efficacy and safety of powered toothbrushes. Adv Dent Res 2002;16:9-15.
13. Addy M, Hunter ML. Can tooth brushing damage your health? Effects on oral and dental tissues. Int Dent J 2003;53 Suppl 3:177-86.
14. Rajapakse PS, McCracken GI, Gwynnett E, et al. Does tooth brushing influence the development and progression of noninflammatory gingival recession? A systematic review. J Clin Periodontol 2007;34:1046-1061.
15. Slim L. Power brushing and recession. RDH. Available at: http://www.rdhmag.com/index/display/articledisplay/2574033117/articles/rdh/volume-30/issue-6/columns/poweredbrushing_and.html) Accessed 15 April 2011.
16. Van der Weijden FA, Campbell SL, Dörfer CE, et al. Safety of oscillating-rotating powered brushes compared to manual toothbrushes: a systematic review. J Periodontol 2011;82(1):5.24. Epub 2010 Sep 10.
Systematic analysis in a nutshell
- What is it? A systematic review asks a research question(s), and then scours the literature to identify all relevant, well-conducted research that speaks to the question. The resulting data are combined when possible, and analyzed (statistically and/or with a qualitative method) to give a summary conclusion.
- Why do it? While well-controlled, individual clinical studies give important insight, synthesizing the combined results of multiple, high-quality investigations will deliver the most definitive answer to the question.
- How rigorous is it? If done correctly, it is very rigorous. All procedures are explicit and predetermined so that the process can be replicated. The literature search is exhaustive. Multiple, independent data screeners/analysts are used to prevent bias.
- What is a meta-analysis? When different studies with similar designs have common clinical measures, the data (results) can sometimes be combined and statistically analyzed for a more powerful estimate of the effect.
- Why aren’t more systematic reviews done? These reviews can be quite time-intensive, requiring dedicated manpower to design and execute searches of the literature and appraise the results.
- What does it mean to me? If you’ve read a well-conducted systematic review, then you can feel confident you’re up to speed on the bottom line of the highest quality research currently available, and your patient product recommendations can be evidence-based.
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