Unclear evidence on the effectiveness of oral hygiene measures for those with intellectual disabilities

The removal of dental plaque by daily toothbrushing plays a major role in preventing tooth decay and gum disease, the two main causes of tooth loss. Toothbrushing is a skill that can be difficult for people with intellectual disabilities; they may require help and people who care for them may need training in how to help them. For this research, we used the World Health Organization’s definition of intellectual disability which is: “a significantly reduced ability to understand new or complex information and to learn and apply new skills. This results in a reduced ability to cope independently, and begins before adulthood, with a lasting effect on development.”

What was the research?

A systematic review to examine the effectiveness of oral hygiene programmes for people with intellectual disabilities.

Who conducted the research?

The research was conducted by a team led by Catherine Waldron of the School of Dental Science, Trinity College Dublin, University of Dublin, Ireland on behalf of Cochrane Oral Health. June Nunn, Caoim Mac Giolla Phadraig, Catherine Comiskey, Suzanne Guerin, Maria Theresa van Harten, Erica Donnelly-Swift and Mike J. Clarke were also on the team.

What evidence was included in the review?

We did a search for evidence on 9 February 2019. We included 34 studies, including 1,785 people with intellectual disabilities, and 354 people who care for people with intellectual disabilties. The studies looked at different ways to keep the mouth and teeth clean, including:

  • special toothbrushes;
  • training carers in oral hygiene measures;
  • training people with intellectual disabilities in oral hygiene measures;
  • supervised toothbrushing in between dental check-ups;
  • the number and timing of dental check-ups;
  • using an individual care plan.

The studies looked at whether these oral hygiene measures had an effect on gum disease and plaque. Some studies also looked at whether the skills of carers or people with intellectual disabilities were improved.

What did the evidence say?

A special manual toothbrush (the Superbrush), used by carers, may be better at reducing levels of gum disease and possibly plaque in people with intellectual disabilities than an ordinary manual toothbrush over 12 months, although studies over shorter periods (less than 6 weeks) did not show an effect. Using an electric toothbrush rather than a manual toothbrush did not seem to make a difference.

Training carers in oral hygiene measures improved their knowledge; and training people with intellectual disabilities how to clean their teeth may have reduced the amount of plaque on their teeth over six weeks.  Having regular dental check-ups, with supervised toothbrushing in between may be more effective than usual care in improving oral health. The use of individualised care plans may also be beneficial.

Only one study set out to formally measure negative side effects; however, most studies commented that there were none. Some studies found that some people had difficulty using the electric or special manual toothbrushes.

How good was the evidence?

The certainty of the evidence was mainly low or very low, which means we are not certain of the results. More studies are needed to confirm the findings.

What are the implications for dentists and the general public?

Changes to current habits based on this review should be made cautiously, and decisions about oral hygiene care should be based on professional expertise and the needs and preferences of people with intellectual disabilities and their carers.

What should researchers look at in the future?

Although some oral hygiene interventions for people with intellectual disabilities show scientific evidence of benefits, what these benefits actually mean for an individual’s oral hygiene or oral health is unclear. The certainty of the evidence is mainly low or very low so future research may change our findings. Moderate‐certainty evidence is available for only one finding: electric and manual toothbrushes are probably similarly effective for reducing gum disease in people with intellectual disabilities over 12 months. More and better research is needed to fully evaluate interventions that show promise for improving the oral hygiene of people with intellectual disabilities, and to confirm which interventions are ineffective.


Waldron  C, Nunn  J, Mac Giolla Phadraig  C, Comiskey  C, Guerin  S, van Harten  MT, Donnelly‐Swift  E, Clarke  MJ. Oral hygiene interventions for people with intellectual disabilities. Cochrane Database of Systematic Reviews 2019, Issue 5. Art. No.: CD012628. DOI: 10.1002/14651858.CD012628.pub2.

You can read the authors’ declarations of interest, here.

This post is an extended version of the review’s plain language summary, compiled by Anne Littlewood at the Cochrane Oral Health Editorial Base.