Oral health advice for people with serious mental illness: lack of evidence about effectiveness

The research found that mindfulness helped more with the negative symptoms of schizophrenia

A number of studies have suggested that people with serious mental illness have a significantly poorer oral health than the general population. Conditions such as schizophrenia may impact on their ability to carry out oral hygiene activities and many regularly prescribed drugs have xerostomia as an adverse effect which increase the risk of caries and periodontal disease. Oral Health advice may have a positive impact on oral health behaviours including mouth care and dental visiting patterns.

The aim of this review was to assess the effects of oral health education (advice and training) with or without monitoring for people with serious mental illness.


Searches were conducted in the Cochrane Schizophrenia Group’s Trials Register. This is based on regular searches of Medline, Embase, CINAHL, BIOSIS, AMED, PubMed, PsycINFO, and clinical trials registries with no limitations.

Randomised clinical trials (RCTs) focusing on oral health education (advice and training) with or without monitoring for people with serious mental illness were considered. Two reviewers abstracted data independently and assessed risk of bias. Risk ratios (RR) and 95% confidence interval (CI) were calculated for binary outcomes and mean difference (MD) and 95% CIs for continuous data.


  • 3 RCTs involving a total of 1358 patients were included.
  • The studies did not provide usable data on key outcomes of not having seen a dentist in the past year, not brushing teeth twice a day, chronic pain, clinically important adverse events, and service use. Data for leaving the study early and change in plaque index scores were available.
  • 1 trial (30 patients) compared oral health education with standard care finding no clear difference between the groups for numbers leaving the study early and a statistically significant change in plaque index, MD= – 0.50 (95%CI; – 0.62 to – 0.38) of questionable clinical importance.
  • 1 trial (60 patients) compared motivational interview + oral health education with oral health education. There was no clear difference in leaving the study early and no clinically important change in plaque index, MD= – 0.60 (95%CI; – 1.02 to – 0.18).
  • 1 trail (1682 patients) compared monitoring with no monitoring demonstrating more leaving early in the no monitoring group.


The authors concluded

We found no evidence from trials that oral health advice helps people with serious mental illness in terms of clinically meaningful outcomes. It makes sense to follow guidelines and recommendations such as those put forward by the British Society for Disability and Oral Health working group until better evidence is generated. Pioneering trialists have shown that evaluative studies relevant to oral health advice for people with serious mental illness are possible.


This review is an update of and extension of a 2011 Cochrane review (Dental Elf 15th Nov 2011), which previously covered only oral health advice. While 3 studies were identified their quality is limited being assessed as either very low quality evidence (2 RCTs) or moderate quality evidence (1 RCT) using the GRADE approach.

Recently NICE has published guidance for oral health promotion in general dental practice and we covered one of the systematic reviews underlying this guidance (Dental Elf -23rd Feb 2016). This found strong evidence to support the use of psychological behaviour change models as the basis for interventions to improve oral health. However the majority of these studies were conducted in normal adult and child populations. The impact of the oral health professionals’ communication skills was considered to have an important impact on outcomes so a lack of familiarity with and understanding of patients suffering from serious mental health problems could have implication on delivery effective advice. As a group of patients who have been shown to have poor oral status the important of good preventive advice a care is greater for this group and more good quality studies need to ensure that we can understand the best ways of delivering effective preventive advice for them.


Primary paper

Khokhar MA, Khokhar WA, Clifton AV, Tosh GE. Oral health education (advice and training) for people with serious mental illness. Cochrane Database of Systematic Reviews 2016, Issue 9. Art. No.: CD008802. DOI: 10.1002/14651858.CD008802.pub3

Other references

Mental Elf -16th Mar 2016

Poor oral health and severe mental illness: what are the links?

Dental Elf -23rd Feb 2016

Oral health promotion in dental practices

Dental Elf –15th Nov 201

Oral health advice for people with serious mental illness

Mental Elf – 21st Sep 2011

Study suggests people with depression and anxiety have lower use of oral health services and greater tooth loss

Mental Elf –7th Sep 2011

Tooth loss three times higher in people with serious mental illness

British Society for Disability and Oral Health Guidelines


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