Title: Silver diamine fluoride for the management of dental caries in children in primary dental care – a feasibility study
Funder: Department of Health and Social Care

Abstract: Background Dental caries remains a significant health problem in England, affecting 12% of 3-year-olds and 23% of 5-year-olds. Children with dental caries suffer pain, infection and poor oral health-related quality of life. There are different approaches for the management of childhood dental caries but it remains the most common reason for a hospital admission in the UK for children aged 5-9 years, costing the NHS 50 million in 2015-2016. While current approaches have been extensively investigated, their ability to: 1) control pain and infection; 2) prevent hospital admissions, and 3) be implemented within the current NHS contractual arrangements, remains unsatisfactory. Silver diamine fluoride (SDF) is an alternative and non-invasive approach that is applied topically (simple to manage for children) and has proven efficacy in arresting caries progression in primary teeth, principally from studies conducted outside Europe. Its use in primary dental care practice in the UK is limited despite acknowledged need. However, the clinical effectiveness of SDF has not been compared to usual care in the UK, so it is unknown which treatment is more effective. Before a pragmatic randomised controlled trial (RCT) can be conducted into the effectiveness of SDF compared to usual care, there are several uncertainties related to recruitment, retention and fidelity that require investigation in a feasibility study.Research QuestionIs an RCT to compare the clinical effectiveness of SDF to usual care for the treatment of caries in children's primary teeth feasible? Aim To establish whether conducting a RCT to compare SDF to usual care for the treatment of caries in children's primary teeth is feasible. Objectives Establish which are suitable primary and secondary outcome measures Calculate the variability of the chosen primary outcome measure Establish whether recruitment, randomisation and retention of participants is feasible Establish the ability to recruit and retain dental professionals Establish the rate of dentists' adherence to the study protocol Assess acceptability and feasibility of delivery of SDF and the research processes for children, families, dentists and key stakeholders using a theoretically-informed process evaluationMethods This mixed-method study is a feasibility study with an embedded process evaluation, to compare SDF with usual treatment in primary dental care in the UK. It will be randomised, with eight dentists, each in a different dental practice and a sample size of 80 participants. There will be ten participants per dentist and equal arm allocation. Follow-up will be for one year. The study will inform whether an RCT is feasible by resolving several key uncertainties. Acceptability and implementation of SDF and the research processes will be explored. PPI representatives will be involved throughout further informing design including recruitment/retention strategies, participant documentation, analysis, engagement and dissemination.Anticipated Impact/DisseminationThe findings of the study will inform the need for, and design of, a pragmatic RCT in primary dental care to meet the burden of caries for children, their families and the NHS. The dissemination strategy includes participants, the public, policy-makers, dental professionals and academics and will be designed with key stakeholders including PPI representatives.

Lay abstract: Dental decay in primary (baby) teeth in children is common worldwide. In England, 12% of 3-year-olds and 23% of 5-year-olds have decay in their primary teeth, it disproportionately affects those from a deprived background. Untreated decay can affect a child's wellbeing and general health. It can cause pain, difficulty eating and sleeping and can lead to missed school and reduced school performance. When teeth are not treated, the decay often progresses, requiring children to have their teeth removed. For young children this frequently necessitates hospital admission and removal of multiple teeth under general anaesthetic (GA). Paediatric dental GAs cost the NHS 50 million in 2015-2016.Many treatments are available for decayed primary teeth (termed 'usual care'), and guidance is provided for dentists working in dental practice (primary care) and dental hospitals (secondary care). Research has shown that, despite this guidance, many children (43%) still develop pain and infection. Alternative solutions are therefore required that are effective at stopping tooth decay progressing, and reducing pain and infection. Silver diamine fluoride (SDF) is a treatment that is widely used internationally, but its use is not common in the UK. It is a quick and non-invasive procedure; SDF is simply painted onto the decayed area of teeth. SDF has a notable side effect in that it permanently changes the yellow-brown colour of tooth decay to black. Research has shown that it is effective at stopping decay progressing, but it has not been compared to usual care in the UK, so we do not know which is more effective. Before a large-scale definitive randomised clinical trial (RCT) can be conducted in primary dental care to compare SDF to usual care for management of decayed primary teeth, there are several important considerations requiring investigation. The proposed research seeks to investigate these uncertainties through a study to assess the feasibility of the definitive trial. These uncertainties include: What is the best method to measure the outcomes of the study? Is it possible to recruit enough dentists and children to take part in a trial? How many children would remain in the study until the end? Are dentists willing to provide the allocated treatment for children in the study? Do parents, children and dentists find SDF and the research processes acceptable?The aim of this research is to establish whether conducting a RCT to compare SDF to usual care for the treatment of decay in children's primary teeth in England is feasible. Children aged 2-6 years with dental decay in their primary teeth will be randomly assigned to either have SDF treatment or usual care. This treatment will be provided by eight dentists in different dental practices involving a total of 80 children. Data will be collected and interviews carried out with families and dental professionals to explore the uncertainties listed above.Patients and service users have already been involved in designing the study, particularly around the setting, recruitment and use of SDF. They will continue to be involved by advising throughout, assisting with production of study information, reviewing the results and planning how to share findings with the public. The dissemination strategy will be designed and implemented with input from the study PPI panel via a website, social media accounts, engagement with the mainstream and dental media in addition to conference presentations, journal articles and an engagement day. The results will be used to plan a large trial to compare SDF to usual care in England, and advise on how best to implement SDF in NHS primary dental care in order to meet the burden of the decay for children, their families and the NHS.

Research activity codes: 6.1 PHARMACEUTICALS
Health categories: ORAL AND GASTROINTESTINAL