"Teeth-brushing advice unacceptably inconsistent," reports The Guardian, while the Mail Online states that a "simple, gentle scrub is best".
These headlines relate to a small literature review that found diversity in the methods of manual toothbrushing recommended by dental associations, toothpaste and toothbrush companies, dental textbooks, and experts in 10 countries. The study authors concluded that this inconsistency "should be of serious concern to the dental profession".
The diversity of advice across the countries was thought to be because of a lack of good evidence about which toothbrushing technique is most effective, which further research could address.
The study has several limitations, but these are unlikely to change its overall message. Despite its small and imperfect nature, this literature review highlights a fundamental issue in dentistry – that the toothbrushing techniques currently recommended are probably not strongly evidence based.
This research may spur dental and other related organisations to provide evidence-based guidance on oral hygiene – and to let the public know which brushing technique works best for kids and grown-ups.
Where did the story come from?
The study was carried out by researchers from the Department of Epidemiology and Public Health at University College London (UCL), and was published in the peer-reviewed British Dental Journal.
No funding source was reported.
Generally, the media reported the story accurately, with the Mail Online including an instructional video of a man brushing his teeth circularly. However, given the research's conclusions, there is no guarantee this is the most effective technique.
What kind of research was this?
The researchers say dentists, dental associations and government bodies all recommend regular daily toothbrushing because it is so important for preventing periodontal disease and caries.
However, there appears to be no consensus among professional bodies on the best method of toothbrushing for the general population, or for people of different ages or with particular dental conditions.
This study aimed to investigate this by conducting a literature review assessing methods of toothbrushing recommended for both adults and children.
What did the research involve?
The research involved examining online material on methods of toothbrushing from:
- dental associations
- toothpaste and toothbrush companies
- associated organisations providing professional advice
- dental textbooks
The consistency of recommendations from different sources was compared narratively.
The study mainly used simple Google and Google Scholar search strategies to identify relevant material, and focused their search remit on 10 countries they deemed to have the highest dental research and recommendation outputs: Australia, Brazil, Canada, Denmark, Finland, Japan, Norway, Sweden, the United Kingdom and the United States. Google Translate was used to translate non-English websites.
A score sheet was used to record relevant information, and the techniques were categorised based on the angle of the toothbrush bristles and the movement of the toothbrush head.
Supplementary information on toothbrushing frequency, duration and powered toothbrushing recommendation was collected.
Pictures and videos that were sourced were reviewed independently by three dentists, and a consensus view was recorded on the techniques they showed.
What were the basic results?
Of 66 sources located, 58 had one or more items of codeable data, while eight sources did not have any useable data. It was not possible to discern a brushing technique from 19 of the sources.
The main finding was evidence of vast diversity between recommendations on toothbrushing techniques, how often people should brush their teeth, and for how long.
Which toothbrushing technique to use?
Overall, the most common method recommended was the modified Bass technique (19 sources). Eleven recommended the Bass technique, followed by the Fones technique (10 sources), the Scrub technique (five sources) and the Stillman technique (two sources). None recommended the Charters technique.
How often should we brush our teeth?
This area seemed to attract the most consensus, with 42 sources recommending brushing twice a day. One recommended three times a day.
How long should we brush our teeth for?
Twenty-five sources did not provide information on brushing duration. Twenty-six recommended brushing for two minutes, 12 recommended brushing for two to three minutes, and two recommended brushing for three minutes. One source recommended brushing for more than three minutes.
Are toothbrushing techniques suggested for adults and children different?
Recommendations on which toothbrushing method to use for adults differed from those for children. The more technically simple Scrub and Fones techniques are advocated for children, with the more complex Bass and modified Bass advocated for adults.
Do the sources of toothbrushing advice differ?
The methods recommended by companies, mainly toothpaste companies, differed from those of dental associations, as did advice in dental textbooks and research-based sources. Dental associations also varied widely in the method of toothbrushing they recommended.
How did the researchers interpret the results?
The researchers concluded that, "There was, unacceptably, very wide diversity in recommendations on toothbrushing techniques, and on how often people should brush their teeth and for how long.
"Such diversity in recommendations should be of serious concern to the dental profession," they say. "There is an urgent need for research into the comparative effectiveness of brushing methods. Higher grades of evidence are required to inform professional bodies that develop guidelines."
This literature review highlighted diversity in the methods of manual toothbrushing recommended for both adults and children by dental associations, toothpaste and toothbrush companies, professional sources such as dental textbooks, and experts in 10 countries.
In the Mail Online, dentist Dr John Wainwright, who carried out the study, was quoted as saying: "The wide range of recommendations we found is likely due to the lack of strong evidence suggesting that one method is conclusively better than another."
In the publication discussion, he added: "In an era of evidence-based dentistry, such a gap in knowledge is surprising."
This study has many limitations, but they are unlikely to affect its overall conclusions.
The research spanned 10 countries and results were grouped together, so it wasn't possible to see if advice and recommendations were at least consistent within the borders of a single country.
Were there consistent recommendations across sources from England, for example? We cannot tell from this publication. It would be useful to know how much of the variation in recommendations occurred between countries – for example, between England and Spain – compared to within countries.
The research did not appear to assess other aspects of peoples' twice-daily oral hygiene routine, including:
- what hardness of toothbrush bristle to use
- electronic versus manual brushing – this appeared to be included in the search, but no results were reported
- flossing technique
- use of mouthwash and type of mouthwash
The selection of sources was based on the availability of online sources searched through Google using simple search terms. This search approach is unlikely to be comprehensive, so may have missed important literature or excluded others.
For example, the authors reported it was difficult to examine sources in foreign languages and therefore there were few non-English sources included in the study – this would have biased the results in favour of English-language material.
Overall, this small literature review highlights a fundamental issue in dentistry – that the current recommended toothbrushing techniques are not strongly evidence based, and that there are numerous recommendations in circulation.