Accessibility statement

Someone sitting by a tooth

Oral Health

‘Closing the Gap- Oral Health’ is a research platform with an aim to address the oral health inequalities in people with severe mental illness. Our goal is to improve oral health of people with severe mental illness by developing and implementing appropriate intervention strategies and work towards reducing oral health inequalities

The problem

Oral health is an important part of general health and wellbeing. Oral diseases affect at least 3.58 billion people worldwide. Tooth decay and gum disease can cause pain and infection and if left untreated can eventually result in tooth loss leading to functional limitations like eating difficulty and poor overall quality of life. Poor oral health also affects aspects of social life, including self-esteem, social interaction, and job performance. Oral diseases are considered a global public health problem with a high economic burden. It has been reported that UK household's expenditure on dental services was more than £3.1 billion in 2019.

People with severe mental illness (SMI) comprise 2-4% of the population in the UK and have some of the worst health indices and lowest life expectancy as compared to any other section of the population. The burden of oral disease is particularly high in people with mental illness and it remains a largely neglected issue. Evidence shows that oral health among people with SMI is poorer than in the national adult general population. They have nearly 3 times higher chance of losing all their teeth and higher rates of tooth decay.

Yet people with SMI are less likely to visit a dentist for routine dental check-ups or treatment. Maintaining regular oral hygiene can be a particular challenge for this population due to less regular maintenance of tooth brushing, high levels of consumption of sugary food and drink, and side effects of antipsychotic medications (e.g. dry mouth). Lack of adequate support and symptoms of mental illness contribute to reluctance to visit the dentist or for maintenance of oral hygiene. All these issues can lead to poor oral health related quality of life in this population.

To tackle poor oral health, this population needs to be urgently targeted with interventions that are tailored to meet their needs.

Who are the partners

  • Dr Masuma Pervin Mishu, Research Fellow, University of York
  • Professor Lina Gega, Porfessor of Mental Health, University of York, Hull York Medical School (HYMS)
  • Professor Simon Gilbody, Professor of Psychological Medicine and Health Services Research, Director Mental Health and Addiction Research Group (MHARG), University of York and HYMS
  • Dr Emily Peckham, Senior Research Fellow, University of York
  • Mr Gordon Johnston (PPI representative)
  • Professor Zoe Marshman, Professor/Honorary Consultant of Dental Public Health. Academic Director of the Oral and Dental Directorate of Sheffield Teaching Hospitals NHS Foundation Trust. School of Clinical Dentistry, Sheffield
  • Dr James Bird, Clinical dentist, Community Dental Service
  • Mr D P Landes, Consultant, Health Care Public Health Team NHS England and NHS Improvement (North East)
  • Dr Michelle Horspool, Deputy Director: Research, Sheffield Health and Social Care NHS Foundation Trust
  • Dr Sarah Daniel, Head of Research, Tees Esk and Wear Valleys NHS Foundation Trust
  • Dr Wael Sabbah, Senior lecturer, King’s College London
  • Dr Alexandra Macnamara, Public Health Registrar, Clinical Teaching Fellow & Honorary Lecturer, Hull York Medical School

Advisory panel

  • Economic evaluation: Steve Parrott, Reader in Health Economics, Department of Health Sciences. University of York
  • Co-production of the intervention: Kevin James, Peer Consultant & Co-Production Advisor. Norfolk and Suffolk Foundation Trust
  • Training: Rachel Lish. Training Programme Director for Oral Health Improvement & Dental Care Professionals. Directorate of Multi-Professional Dental Education, Health Education England

Work done so far

1. Patient and public involvement to identify the research need

We conducted patient and public involvement (PPI) to explore service users’ perceptions and the need for an oral health intervention in this context.

The PPI group considered that oral health in people with SMI is an important but neglected area of focus so far and they suggested for further research in this area.

2. Conducting a systematic review on improving oral health in people with severe mental illness

3. In depth interviews and stakeholder consultations for investigating barriers and facilitators and potential intervention components for interventions to improve oral health in people with SMI

In depth interviews

Seventeen in depth interviews were conducted with both the service users (people with lived experience of Schizophrenia, bipolar disorder) and service providers such as dental professionals (high street, community and special care dentists and dental hygienist), and mental health professionals (mental health nurses, clinical psychologist and occupational therapist) and carers. During these interviews, barriers and facilitators for different aspects of oral health in this population were discussed along with potential intervention components of an oral health intervention.

Stakeholder consultation

Ten meetings with different stakeholders were conducted to discuss barriers and facilitators for oral health and formulate potential intervention components that would be ethically appropriate, feasible and acceptable to both the service users and service providers.


  1. Publication of the systematic review on ‘Improving oral health in people with severe mental illness (SMI)’
  2. Identification of barriers and facilitators

The key barriers and opportunities identified from interview discussion and stakeholder consultation were:


  • Difficulty accessing a dentist
  • Lack of availability of tailored support
  • Disconnect between mental and dental services
  • Treatment associated costs
  • Dental anxiety and phobia


  • Training the staff to initiate conversations around mental and oral health
  • Provision of support at a mental health setting such as tailored oral health advice, referral to inhouse dietary support team, and practical support with setting up an appointment and attending the need appropriate dentist
  • Involvement of carers (family/friends etc) to provide day-to-day support with oral hygiene (toothbrushing with fluoride toothpaste) and dietary behaviours (healthy diet as opposed to that high in sugars)

3. Suggestions for potential intervention components

Incorporation of a dental checklist on self-reported oral health condition and dental service use of people with SMI at community mental health services as part of their routine physical health check-up by the mental health nurses (six monthly).

Tailored advice and practical support on dental attendance (motivating for regular dental visit for routine check-up and treatment, practical help for arranging and attending dental appointment, claiming exemption of cost etc.) could be provided by the care coordinators.

Incorporation of standard toothbrushing advice as recommended by the British Society of Disability and Oral Health (BSDH) for correct technique and duration.

The intervention could also include BSDH recommended dietary advice for reducing frequency of sugar intake.

Practical support could be provided by distributing toothbrushes and fluoride toothpaste (for caries prevention), personally tailored toothbrushing reminder system and referral to the onsite diet counsellor for support with controlling sugar consumption.

The intervention would also allow opportunity for carer involvement including family and friends, to provide support. Provision of appropriate training to the mental health care staff in intervention delivery.

4. Suggestions for potential success criteria

Suggested potential measures of success would be (i) an increase in the use of dental services for check-ups (ii) maintenance of regular oral hygiene and reduction in intake of dietary sugars.

5. Development of logic models to demonstrate the mechanism of potential intervention

We developed three logic models to demonstrate how the proposed intervention components (the behaviour change techniques) mapped with the potential outcomes.

Future work

Title of our proposed intervention: Enabling Service Users with Severe Mental Illness to Learn about and Engage (SMILE) with Good Oral Health: Co-production, Feasibility and Acceptability of a Systems intervention

Aim: Co-production of an oral health intervention to improve oral health in people with severe mental illness and testing its feasibility and acceptability


  1. Co-produce materials for a behaviour change intervention with service users living with SMI to increase their use of dental services, improve oral hygiene and reduce intake of dietary sugar
  2. Co-produce a service-level blueprint and training materials with professionals to be able to integrate and deliver the intervention in routine care
  3. Test the feasibility and acceptability of the co-produced oral health intervention by measuring uptake of and adherence to the intervention, and completion of outcome measures at follow-up points
  4. Capture the experiences of service users with SMI who participate in the intervention and of the professionals who support them.

The proposed study will be conducted in the UK involving mental health care settings and the dental health care settings. The feasibility study will be carried out in collaboration with Sheffield Health and Social Care NHS Foundation Trust and Tees, Esk and Wear Valleys NHS Foundation Trust.

The project is expected to lead to an acceptable and feasible intervention that will be ready to be tested for effectiveness and cost-effectiveness through a large-scale RCT with an embedded pilot (under future funding), with an aim to improve oral health outcomes and quality of life for people with SMI.

Potential impact

Health and well-being
This will be the first co-produced intervention of this type, which has the potential to directly benefit people with SMI by improving their oral health related outcomes and oral health related quality of life (OHRQoL). This will also have positive impact on their general health and wellbeing, increase their level of confidence and social interaction leading to improved productivity.

Health service-related impact
It is an NHS priority to ensure parity of esteem between mental and physical health. Oral health is an integral part of both physical and mental health. This widening health inequality has been listed as a priority in the NHS Long Term Plan, which stresses the urgent need for scalable, low-cost interventions to prevent and reduce the impact of mental disorders One way to reduce this gap is to provide targeted interventions tailored to the needs of people with SMI. However, current evidence is not sufficient to guide NHS practice and policy for addressing important drivers of poor oral health. The recently proposed ‘NHS Place-based community health model’ proposes an integrated care model with one of its aims being to “maximise continuity of care and ensure no ‘cliff-edge’ of lost care and support by moving away from a system based on referrals, arbitrary thresholds, unsupported transitions and discharge to little or no support. Instead, move towards a flexible system that proactively responds to ongoing care needs”.

In line with the proposed NHS model, our proposed project (Enabling Service Users with Severe Mental Illness to Learn about and Engage (SMILE) with Good Oral Health: Co-production, Feasibility and Acceptability of a Systems intervention) if found to be effective and cost effective in a full phased trial, will provide evidence to support the move towards an integrated care model. Due to COVID-19, there is an increased chance of facing challenges for accessing dental health care services which can further increase the oral health inequality gap for the population with SMI. Therefore, there is an urgent need to address this issue by developing a tangible and effective intervention to improve oral health for this population.

Research impact
It is important to develop effective interventions that will address the specific challenges faced by people with SMI and reflect their preferences, not only by promoting the individual level behaviour change but also institutional level changes. This will create opportunities to improve oral health among people with SMI. So far, the evidence suggests:

  1. There is lack of high quality trials of interventions to improve oral health among people with SMI
  2. None of intervention studies have reported any clinically significant difference in the oral health of people with SMI
  3. No study has reported co-development of an intervention to address the barriers and facilitators, and expectations of the people with SMI and the service providers, by considering the wider determinants and providing a supportive environment to help sustain the positive changes
  4. Lack of assessment and reporting of various key outcomes such as change in oral health behaviours and dental service use, occurrence of adverse events, quality of life including oral health aspects of social life such asself-esteem and social interaction.

The proposed intervention, co-designed in collaboration with stakeholders, will aim to address these research gaps.

Capacity building
This research will allow training of the mental and dental service providers about initiating mental and oral health conversations with the service users under their care. Thus, helping to bridge the gap between mental and dental care service provision.

Economic impact
Oral diseases are considered a global public health problem with a huge economic burden. Complication from untreated dental decay has been reported to be the commonest reasons for non-psychiatric multiple hospital admissions among people with SMI that has implications on a person’s health, health service and costs of treatment. There have been reports indicating a potential to decrease health care expenditure by supporting oral health of people receiving mental health care. Currently, there is insufficient good-quality evidence to support a policy change for oral health care of this population. Therefore, the designed intervention, if proven to be effective and cost effective, could be implemented in health care practices to help improve oral health and quality of life among people with SMI, thus helping to reduce the health gap between people with SMI and the general population. This intervention could be implemented in the NHS health care system and has potential to reduce dental treatment and mental health care related cost.

Policy impact
Policymakers and managers could use the findings for identifying and implementing evidence-based policies in order to achieve quantifiable outcomes. Dental professionals across NHS practices, GP services and mental health services will have the potential to support further improvement of oral health for this population. Oral health care guidelines for people with mental health problems, have been previously developed by the British Society for Disability and Oral Health working group are based on limited evidence. Our study will contribute by providing evidence in a wider perspective to help update the guidelines, as we will liaise with clinicians and oral health professionals for developing novel ways to cater for the needs of people with SMI, who have well-documented difficulties in accessing mainstream healthcare services.


Dissemination plan

We will disseminate outputs to likely beneficiaries of the research, including academic audiences, individuals and organisations involved in health service delivery, commissioning and policy, clinicians working in primary care, mental and dental health care and specialist services, people with SMI and carers; social care providers and managers; and other organisations supporting people living with severe mental illness. We will use innovative strategies for different audiences using formats they are most likely to engage with, supported by our PPI group and collaborators. We expect to use a combination of written reports, oral presentations, animations, websites, podcasts, webinars and other forms of social media and professional networks.

The finding will be disseminated to civil society organizations, non-profit organizations, government bodies working in the area (NHS), and national networks – the UKRI Mental Health “Closing the Gap” network, MIND UK, the Mental Health Network of the NHS confederation and the Mental Health innovation and dental health Networks.

Academic dissemination will be done via peer-review publications and scientific conferences.

Dissemination Activity so far:

  1. Press release
  2. Conference  presentation:''Interventions to improve oral health for people with severe mental illness: barriers and facilitators from the perspective of service users and service providers.''
    Primary Care Mental Health Research Conference 2022 , ' Mental Health: Safety, Quality and Effectiveness', 25th May 2022 , UK
  3. Conference presentation: ''Barriers and Facilitators for Maintaining Oral Health and Dental Service use in People With Severe Mental Illness.''
    International Association for Dental Research (IADR) Conference, 20-25 June 2022
  4. Animation presenting the findings of the Closing the Gap Oral Health Study: 'Barriers and Facilitators and Recommended Interventions to Improve Oral Health in people with Severe Mental Illness'.