Oral Health Services and Clinical Epidemiology Research Group

Our team undertakes oral health research in addition to evidence-based research and meta-research projects to inform practice and policy
Oral Health Services and Clinical Epidemiology Research Group
The Oral Health Services and Clinical Epidemiology Research Group is an interdisciplinary research group working with researchers, practitioners and stakeholders in the dental school, the wider University of Plymouth, organisations and universities in UK and internationally. We capitalise on our connection across the University including PenARC, Plymouth Institute of Health and Care Research (PIHR), Centre for Health Technology, Sustainable Earth Institute and a wide range of international collaboration in Europe, Asia, Africa, Australia and America.
Our research focuses oral health services research along with meta-research projects on evaluating and synthesising data to inform policy and practices. We work on interventions to improve oral health and reduce inequalities, identifying innovative ways to engage with hard-to-reach or disadvantaged communities. We work on conducting systematic reviews of human, animal and in-vitro studies in dentistry and other fields and conducting meta-research studies to innovate the methodologies in the field. Finally, we study decision making in dentistry and how we can use technological solutions to support patients and clinicians.
In addition to our research interests, we are keen to ensure that the current evidence is translated into policy and practice so we are also involved in engaging with stakeholders to ensure that our research get implemented. 
For further information, please contact Professor Mona Nasser.

Featured impact

Towards an evidence informed approach to set priorities for research and allocate research funding

Our school has hosted the Cochrane Priority Setting Methods Group from its establishment in 2011 and was involved in several projects to develop and evaluate research priority setting methods but also work with REWARD campaign to evaluate the processes at national research funders. Our work contributed to REF impact case studies in 2014 and 2021.
In the last 10 years, we further developed the methods of setting priorities for research that has led to changes how organisations approach research prioritisation. 
 

Engaging people experiencing homelessness with oral health promotion

People who experience homelessness have higher dental treatment needs and poorer oral health-related quality of life compared to the general population. However, their utilisation of dental services and levels of treatment completion are low. A systematic review by University researchers in collaboration with Public Health England (PHE) concluded that homelessness can both increase needs and raise barriers to accessing care, exacerbated by how services are arranged. This review, the first to conceptualise factors impacting on people experiencing homelessness, identified a need for dental services to be reconfigured and delivered in a way that recognises patients’ complex and diverse needs, whilst targeting their ability to seek and obtain care. Building on the review’s findings and previous work, a university team developed and conducted ‘Teeth Matter’, a project that explored motivational interviewing by ‘Peer Educators’ (individuals with lived experience of homelessness) to improve patients’ plaque management. The project, the design of which drew on interviews with stakeholders (homeless centre residents, and care/service providers) along with a student project improved our knowledge of the oral health profile of the target group, their treatment needs, and the impact of oral disease on their quality of life. It also provided a good understanding of barriers and enablers to taking care their teeth and accessing local services. Through developing, implementing and evaluating the project, we have made recommendations for engaging people experiencing homelessness with oral health promotion.
Considering the significant NHS dental waiting list in Plymouth and repeated calls for improved access, Peninsula Dental Social Enterprise established a community dental clinic in January 2018 for those experiencing homelessness. The clinic is currently a pro bono contribution to the local community. Although initially, the clinic treated people experiencing homelessness, it now also provides care to individuals using drug and alcohol services, as well as vulnerable women who risk of having multiple children removed from their care. The findings from the research work were and continue to be used to inform the development of the service. Research evaluation findings indicate that, as well as helping patients with pain relief, functionality and motivation to look after their teeth, treatment impacts positively on their confidence, self-esteem, self-worth and aspirations for a new start in life. 
The evaluation identified dental treatment as a catalyst for change in multiple areas of a patient’s life:
"Emotionally he’s transformed, nutritionally he’s put on weight because he’s able to eat, his self‐esteem, his confidence and employment opportunities, his sense of worth is now fully established … his decision was ‘I either continue on this path of destruction’, which was very much influenced by his childhood experiences, or ‘I survive and thrive and I move forward’. And he chose the latter, and part of that was because he was linked to the dental school.’ (Support Worker)
This work has been shared with PHE and one of its working groups, which is developing national guidance on dental care for vulnerable adults. The work has also recently been included in Plymouth City Council’s Oral Health Needs Assessment (2019) and will be used to develop improved NHS dental services for this patient group in the city and wider region.
Selected links
 

Assessing the evidence around dental teams’ mental health and wellbeing

Anastasios Plessas, previously an Academic Clinical Fellow with Peninsula Dental School and current PhD student, lead a review commissioned by the General Dental Council, assessing the evidence around dental teams’ mental health and wellbeing, as well as interventions aiming to prevent and improve mental wellness in dental practice. Our work concluded that dentists, general dental practitioners in particular, suffer an increased level of stress and burnout, with litigation and regulation being the main stressors. However, there was little or no research on the wellbeing of dental care professionals, such as dental nurses, dental hygienists and dental therapists. Current research has focused on secondary and tertiary prevention, whilst studies on system level interventions are currently lacking. The findings of our review emphasised the increased recognition of the contribution of 'latent' or 'system-related' factors, related to the organisation and delivery of healthcare, in ensuring patient safety, through safeguarding of mental wellbeing for the staff involved in the delivery of care.
 

Featured publications

  • Barbeau VI, Madani L, Al Ameer A, Tanjong Ghogomu E, Beecher D, Conde M, Howe TE, Marcus S, Morley R & Nasser M 2022 'Research priority setting related to older adults: a scoping review to inform the Cochrane-Campbell Global Ageing Partnership work programme' BMJ Open 12, (9) , DOI Open access
  • Kumbargere Nagraj S, Eachempati P, Paisi M, Nasser M, Sivaramakrishnan G, Francis T & Verbeek JH 2022 'Preprocedural mouth rinses for preventing transmission of infectious diseases through aerosols in dental healthcare providers' Cochrane Database of Systematic Reviews 2022, (8) , DOI
  • Erwin J, Paisi M, Neill S, Burns L, Vassallo I, Nelder A, Facenfield J, Devalia U, Vassallo T & Witton R 2022 'Factors influencing oral health behaviours, access and delivery of dental care for autistic children and adolescents: A mixed‐methods systematic review' Health Expectations , DOI Open access
  • Eachempati P, Büchter RB, KS KK, Hanks S, Martin J & Nasser M 2022 'Developing an integrated multilevel model of uncertainty in health care: a qualitative systematic review and thematic synthesis' BMJ Global Health 7, (5) , DOI Open access
  • Tan A, Nagraj SK, Nasser M, Sharma T & Kuchenmüller T 2022 'What do we know about evidence-informed priority setting processes to set population-level health-research agendas: an overview of reviews' Bulletin of the National Research Centre 46, (1) , DOI Open access
  • Kumbargere Nagraj S, Eachempati P, Paisi M, Nasser M, Sivaramakrishnan G & Verbeek JH 2020 'Interventions to reduce contaminated aerosols produced during dental procedures for preventing infectious diseases' Cochrane Database of Systematic Reviews 0, (10) 0-0 , DOI Open access
  • Lund H, Juhl CB, Nørgaard B, Draborg E, Henriksen M, Andreasen J, Christensen R, Nasser M, Ciliska D & Clarke M 2020 'Evidence-Based Research Series-Paper 2 : Using an Evidence-Based Research approach before a new study is conducted to ensure value' Journal of Clinical Epidemiology 129, 158-166 , DOI Open access
  • Tugwell P, Welch VA, Karunananthan S, Maxwell LJ, Akl EA, Avey MT, Bhutta ZA, Brouwers MC, Clark JP & Cook S 2020 'When to replicate systematic reviews of interventions: consensus checklist' BMJ m2864-m2864 , DOI
  • Plessas A, Nasser M, Hanoch Y, O'Brien T, Bernardes Delgado M & Moles D 2019 'Impact of Time Pressure on Dentists' Diagnostic Performance' Journal of Dentistry , DOI Open access
  • Nasser M, Clarke M, Chalmers I, Brurberg KG, Nykvist H, Lund H & Glasziou P 2017 'What are funders doing to minimise waste in research?' The Lancet 389, (10073) 1006-1007 , DOI Open access
  • Moher D, Glasziou P, Chalmers I, Nasser M, Bossuyt PMM, Korevaar DA, Graham ID, Ravaud P & Boutron I 2016 'Increasing value and reducing waste in biomedical research: who's listening?' The Lancet 387, (10027) 1573-1586 Author Site , DOI Open access
 

Featured projects

Peninsula Dental Social Enterprise (PDSE) community clinic

The research group works closely with Peninsula Dental Social Enterprise (PDSE). PDSE (listed as one of the top 100 social enterprise companies in the country) is a not-for-profit organisation and the clinical arm of Peninsula Dental School. It works closely with local communities, partner agencies and NHS Commissioners to improve oral health and reduce inequalities through education, community engagement, training and treatment. It uses evidence-based approaches to improve access to dental care for all, particularly those excluded from mainstream dentistry.

PDSE has developed a community clinic which treats people experiencing homelessness, individuals using drug and alcohol services, as well as vulnerable women who risk of having multiple children removed from their care free of charge and has won numerous prizes for its work. In 2020, the clinic was the winner of the South West Region Health Equalities Award. It has been shortlisted for a National Health Service (NHS) Equalities Awards. Further work is underway to broaden access to more vulnerable groups.

Privacy-preserving robotics in dentistry

Privacy-preserving Robotics in Dentistry project is an interdisciplinary initiative between dentistry, robotics and cyber security. Socially-assistive robots have been used in other settings e.g. dementia and autism with positive results in supporting patients in performing tasks or reducing anxiety. There were smaller studies done on children in dentistry demonstrating that it can help them to cope with anxiety and stress better. However, there is a number of areas of dental care especially with challenging patients that socially-assistive robots can be helpful. We are currently working with different groups to identify these areas, design and adapt the intervention and evaluate their effectiveness. We also take cyber security aspects into account, aiming at designing and providing a secure robotics system for dental care.

Systematic reviews of clinical and pre-clinical research

We have a series of projects that involve synthesising studies of clinical and pre-clinical research (animal and human studies). We conduct meta-research studies to innovate the methods to address the needs of these reviews. These reviews include:

In a team with researchers from QUEST centre/Berlin Institute of Health (that hosts the CAMARADES coordinating centre) along with researchers and interns based in the Space Medicine Team of European Astronaut Centre/European Space Agency (ESA) and researchers based in University of Glasgow, UC Irvine. Currently, we work on two systematic reviews on impact of ionising radiation. Our projects are available on Open Science Forum: "Are there sex differences in susceptibility to ionised radiation" and "Non-neoplastic effects of ionising radiation on central nervous system - a systematic review."

Systematic reviews in Dentistry: In previous surveys of systematic reviews of in-vitro studies, a large number of the reviews are conducted in dentistry that reflects the importance of in-vitro studies in dental research, policy and practice. We worked on systematic reviews that involved clinical and in-vitro studies e.g. "Systematic review to assess the effectiveness of mechanical preparation of abutment teeth on the survival of resin bonded bridges". We are currently working with the space dentistry ESA topical Team to synthesise studies involving human, animal and in-vitro studies to inform dental guidelines.

As part of this project, we introduced a series of innovation that includes new quality assessment for in-vitro studies (see the tools and guidelines section) along with developing machine learning algorithm that can screen complex data in addition to the findings of the reviews.

    Kim DS, Weber T, Straube U, Hellweg CE, Nasser M, Green DA, Fogtman A. The Potential of Physical Exercise to Mitigate Radiation Damage-A Systematic Review. Front Med (Lausanne). 2021 Apr 29;8:585483. doi: 10.3389/fmed.2021.585483. PMID: 33996841; PMCID: PMC8117229.
    Nasser M, Fogtman A, Mackay M, et al. Methodological innovation/Adaptation for systematic reviews for space medicine. International Astronautical Conference, Dubai, Oct 2021.

Watch Dr Mona Nasser talk about space medicine

CogNovo

Between 2014-2017, we were part of an innovative Doctoral Programme called CogNovo funded by the EU Marie Skłodowska Curie initiative and the University of Plymouth, to foster research training in the emerging field of Cognitive Innovation. CogNovo offered transdisciplinary training that combined scientific studies of the neural correlates and mechanisms of creativity, with investigations into the role of creativity in human cognition, and their application in sustainable technological and social innovation. The project continued beyond CogNovo, this included a funding from Plymouth Health Global Research fund to support a conference (Off the lip) and research residency (Collaboratoire) in Philippines in partnership with the SEADS network focusing on cognitive innovation in sustainability.

One of the CogNovo projects included Agatha Haines project on 'Ideas Exchange: Design and the post bio-tech body'. Her work included a reflection on design and procedures in dentistry from the speculative design perspective.

Watch the Collaboratoire video on Vimeo

Haptic dental simulation models

Project Leads:

  • Professor Michael Punt, Professor of Art and Technology, School of Art, Design and Architecture
  • Dr Hannah Drayson, Lecturer in Digital Art & Technology/Immersive Media Design, School of Art, Design and Architecture
  • Dr Mona Nasser, Associate Professor of Evidence Based Dentistry, Peninsula Dental School
Co-investigators: 

Anxious patients, children and individuals with physical and intellectual impairments can make sudden unexpected movements when receiving dental treatment, often in anticipation of what they think is to come. Dentists need to learn how to manage and anticipate these reactions to prevent harm to the patient, but most dentists are only able to learn these skills through their individual experiences of patient care.

This project used video-based observation research methods from the humanities to explore such complex interactions between patient and dentist. By analysing video data, such as facial expressions, eye gaze patterns and non-verbal communication skills, a taxonomy of patient reactions to dental treatment was developed. This analysis revealed some evidence of patient anxiety which students need to be sensitive to, and the project offers an example of how we can make more useful videos in this context (i.e. by repositioning cameras etc.).

This project will contribute to education research and the analysis will be used to develop a proof of concept/framework for a training module or CPD programme. This module will make use of a video ethnographic film tool kit and video reflexive exercises during debriefing sessions to develop an understanding of visual literacy. It is also anticipated that the project will be a pilot for a larger and more extensive project to enhance simulation education.

Aerosols during dental procedures

Many dental procedures produce aerosols that can be contaminated with pathogenic microorganisms and can pose a risk for the spread of infections between dentists and patients. This became an important topic during the COVID-19 pandemic due to concerns around transmission of the virus during the procedures. Our group has been involved in two Cochrane reviews led by Sumanth Kumbargere, (one of our PhD students) with a multinational team from UK, Malaysia, Netherlands and Bahrain. The project has been featured on Dental Elf. The data from one of the reviews also support one of the reports of the Scottish Dental Clinical Effectiveness Programme.

Kumbargere Nagraj S, Eachempati P, Paisi M, Nasser M, Sivaramakrishnan G, Verbeek JH. Interventions to reduce contaminated aerosols produced during dental procedures for preventing infectious diseases. Cochrane Database Syst Rev. 2020 Oct 12;10(10):CD013686. doi: 10.1002/14651858.CD013686.pub2. PMID: 33047816; PMCID: PMC8164845. Interventions to reduce contaminated aerosols produced during dental procedures for preventing infectious diseases - PubMed (nih.gov)

Kumbargere Nagraj S, Eachempati P, Paisi M, Nasser M, Sivaramakrishnan G, Francis T, Verbeek JH. Preprocedural mouth rinses for preventing transmission of infectious diseases through aerosols in dental healthcare providers. Cochrane Database Syst Rev. 2022 Aug 22;8(8):CD013826. doi: 10.1002/14651858.CD013826.pub2. PMID: 35994295; PMCID: PMC9394685. Preprocedural mouth rinses for preventing transmission of infectious diseases through aerosols in dental healthcare providers - PubMed (nih.gov)

Impact of enhanced personal protective equipment in dental practice

Exploring the impact of enhanced personal protective equipment upon patient communication and wider clinical practice within primary care dental settings

One of our Academic Clinical Fellows (Alexander Legge) led this project in collaboration with Mona Nasser and Jos Latour.

Literature within the general healthcare setting suggests that enhanced-PPE impacts upon healthcare workers’ communication and clinical skills, and this study aimed to take steps towards exploring how enhanced-PPE impacted upon dental practice.

The project team conducted qualitative interviews utilising an interpretative phenomenological analytic methodology to explore the lived experiences of dental practitioners. Analysis indicated that practitioners perceived enhanced-PPE to have a negative impact upon communication, impairing the building of practitioner-patient relationships and causing strain between colleagues. Dentists also experienced additional physical and psychological stress when using enhanced-PPE, which was perceived to compromise the care provided to patients.

It is important to consider the likelihood of similar pandemic events affecting the provision of community healthcare services in the future, and to use the experiences of healthcare workers to improve preparedness. There is a need to work towards striking a balance between using enhanced-PPE in a way which is protective, whilst minimising its impact on communication, clinical skills and reducing wastage.

The use of enhanced levels of personal protective equipment became necessary when undertaking many routine dental procedures during the COVID-19 pandemic and immediate post-pandemic era.

Oral health of children with disabilities in Dubai

This project is led by one of our PhD students Shiamaa Shihab Ahmed Al Mashhadani. Shiamaa is based at the Dubai Health Authority and is currently undertaking a PhD on how to improve oral health for children with a disability.

Good oral health contributes to improving general health and wellbeing and quality of life. Various studies have shown dental care was the most commonly reported unmet service need impacting quality of life, social, emotional and physical wellbeing in children with disabilities. There have also been challenges that face the children in terms of access to dental care, availability of preventive intervention, oral health literacy and education to the caregivers and challenges involved in providing oral health care and services.

The project aims to identify the barriers and enablers of oral health for children with disabilities to set a conceptual framework to include all the factors that support the improvement of oral healthcare for children with disabilities in the perspectives of the caregivers and parents, dental and medical health providers.

Shiamaa is also active in giving presentations on oral health promotion and she was featured as one of the leading women in dentistry by FDI World Dental Federation.

Taxonomy of uncertainties in health care and oral health care

Systematic review driven conceptual model of uncertainties in health care to guide a primary participatory research to explore how different individuals respond to uncertainties in oral health decisions.

Uncertainty pervades every aspect of the health care system. Identifying the different meanings and conceptual models of uncertainty proposed in health care with a systematic review will allow us to explore the patterns emerging from such models so that we can move further to identify how people interpret and respond to such uncertainties. One of our PhD students led a systematic review to develop a holistic model of uncertainties that covers different levels of decision-making in healthcare. This review is a key part of the PhD and shapes a study involving a multi-ethnic and multi-language group of dentists and patient in Malaysia to understand how individuals perceive and manage under certainties in dental decisions.

This systematic review was able to deconstruct the separate layers of uncertainty affecting health decisions and allowed the team to acknowledge that uncertainty can change and evolve during interactions between different people. The framework will be used to design a primary participatory research which intends to explore how individuals of different ethnicities and uncertainty tolerance respond to uncertainties in oral health decision.

Developing an integrated multilevel model of uncertainty in health care: a qualitative systematic review and thematic synthesis

Watch Prashanti Eachempati present SR to develop taxonomy of uncertainty

Multi Ethno-Linguistic Toolkit (MELT)

Sumanth Kumbargere and Prashanti Eachempati, two of our PhD students, are leading the development a toolkit with a wider team (Mona Nasser, Seilin Uhm – University of Southampton and Soumyadeep Bhaumik – the George Institute for Global Health in India) are working on developing a toolkit for the development and implementation of a research projects and research priority setting exercises (RPS) involving a multiethnic and multilanguage groups. It builds on their PhD work on engaging with multi-ethnic and multi-language group along with other stakeholder engagement projects done by the wider team. The project is done in partnership with Cochrane Priority Setting Methods Group.

Watch Sumanth Kumbargere Nagraj present 'Involving multi-ethnic groups in EBR process'

Featured international projects

Cochrane Priority Setting Methods Group

The research group hosts the Cochrane Priority Setting Methods Group. The methods group is part of Cochrane and focuses on developing methodology and advise Cochrane and its entities about the empirical evidence available on methods for research priority setting or developing research agenda. It also serves as a discussion forum connecting people interested in methods to set research agendas or priorities inside and out of Cochrane. The methods group involves researchers from University of Plymouth, University of Ottawa (Canada), University College London, Campbell Collaboration (international), University of Modena (Italy), University of Edinburgh, the George Institute for Global Health (India), Melaka-Manipal Medical College (Malaysia). A featured recent project is that we are working on how to engage with a multi-ethnic and multi-language stakeholders group in setting priorities for research in oral health in Malaysia.

EVBRES (Evidence-Based RESearch)

We are part of a COST-EU Action project called EVBRES (Evidence-Based RESearch) a four year (2018-2022) EU-funded COST function CA-17117. The collaboration encourage researchers and other stakeholders to use an Evidence-Based Research (EBR) approach while carrying out and supporting clinical research – thus avoiding redundant research. The project involved 109 participants representing 37 European Countries.

ColLaboratoire Multiple disciplinary Research Leadership Summer School 2019-2020

ColLaboratoire 2020 is a week-long research residency program in multiple-disciplinary research and sustainability, especially in the context of Philippines. During the residency, ColLaboratoire Fellows will explore applying imaginative, methodologically innovative, and radically multiple-disciplinary approaches to six research challenges related to the UN Sustainable Development Goals. For one week on the island of Siargao, ColLaboratoire Fellows will look at innovative ways to address the research challenges that combine teaching with applied and multiple-disciplinary research practice.

Inspired by the successful ColLaboratoire 2016 research summer school, ColLaboratoire 2020 is a collaboration between the University of the Philippines Open University, the University of Plymouth, the CogNovo Foundation for Cognitive Innovation, and local and international partners from industry and civic society.

Watch Collaboratoire, Siargao Philippines January 2020 on Vimeo

Videos of our research

Research tools and guidelines

Quality assessment tool for in-vitro studies

This quality assessment tool was developed as part of the collaboration with researchers of European Astronaut Centre (ESA) and QUEST centre/Berlin Institute of Health. It is a quality assessment tool for in-vitro studies focusing on impact of ionising radiation that can be further generalised to other fields OSF | Quality assessment tools for in-vitro studies. We are currently finalising a new checklist for in-vitro dental material studies that will be available soon.

Equity lens for research priority setting

The Cochrane Priority Setting Methods Group worked along with the Campbell-Cochrane Equity Methods Group to develop an equity lens to guide future prioritisation and agenda setting strategies for systematic review groups. Although the guideline was written specifically targeting Cochrane groups. It can be used and expanded to other research priority setting exercises.

We are currently developing an updated version of the tool that be available soon.

WHO guidance on Research Methods for Health Emergency and Disaster Risk Management

The WHO guidance on Research Methods for Health EDRM is the culmination of many face-to-face and virtual consultations among experts from WHO, member states and partner organisations, who have contributed to the development and review of this document. The guidance is derived from the existing scientific evidence in Health EDRM, and is delineated in 43 chapters that cover a wide range of research fields. The project was coordinated by WHO Kobe Centre. Our research group contributed to developing chapter 2.7 on priority setting methods.

Our team

External collaborators

Research students

  • Mark Steven Howe (PhD student/ DOS: Mona Nasser) Probability risk index in restorative dentistry
  • Sumanth Kumbargere (PhD student/ DOS: Mona Nasser) Equity oriented to set priorities for research
  • Shiamaa Al Mashhadani (PhD student/ DOS: Mona Nasser) Oral Health care of children with disability in United Arab Emirates
  • Nick Perez (PhD student with transtechnology research group) Cinematic interface for cognitive exploration in (medical) simulation
  • Prashanti Eachempati (PhD student/ DOS: Mona Nasser) Understanding how people interpret and respond to uncertainties in oral health -related information: an study among selected multi-ethnic groups in Malaysia
  • Nicole Thomas (PhD student/ DOS: Mona Nasser) Evaluation of a Multicomponent Oral Health Education Intervention in a Vulnerable Infant Population: a mixed methods study
  • Anastasios Plessas. (PhD student / DOS: Rob Witton) The impact of inter-professional education in the dental curriculum on students’ views towards social accountability

Academic Clinical Fellows

  • Alex Pollard (Academic Clinical Fellow). Research interests include Head and Neck Cancer, Periodontology, Socially assistive Robots in Dentistry.
  • Gabriele Baniulyte (Academic Clinical Fellow)
  • Alexander Legge (Academic Clinical Fellows in Primary care/ MClinRes student) The impact of enhanced PPE on clinical performance and communication

Visiting researchers

  • Yvette Gonzalez, MPH, Senior Climate Researcher, Sky Indicators project
  • Gulcan Tecrili - Health Economist, Turkish Ministry of Health (Supported by Short Scientific Mission (STSM) COST EU Action EVBRES)
  • Sumanth Kumbargere - Faculty of Dentistry (Manipal University, Melaka campus)
  • Shiamaa Al Mashhadani - Dental Services Department, Dubai Health Authority
  • Alexandru-Petru Vasile - Intern, European Space Agency, Cologne, Germany (Supported by Short Scientific Mission (STSM) COST EU Action EVBRES)