How to fix holes in baby teeth? Silver diamine fluoride for the management of dental caries in children in primary dental care: A feasibility study to determine whether a randomised controlled trial of silver diamine fluoride compared to usual care for the management of caries in children’s primary teeth is feasible in UK primary dental care.

Background and aim
Silver diamine fluoride (SDF) treatment offers a non-invasive approach for arresting caries progression but its use in NHS primary dental care is limited. Furthermore, the clinical- and cost-effectiveness of SDF has not been compared to usual care in this setting. This study aimed to determine whether a randomised controlled trial (RCT) was feasible.
Methods
This was an individually randomised mixed-methods feasibility study comparing SDF to usual care in NHS primary dental care with an embedded process evaluation exploring SDF implementation. Children aged one- to eight-years, with caries in their primary dentition, were followed up for six to twelve-months. The following aspects were assessed: child and dental professional recruitment and retention; randomisation; suitability of outcome measures; protocol adherence; research acceptability and implementation. Interviews with families, dental professionals and national/regional stakeholders utilised the Consolidated Framework of Implementation Research (CFIR).
Results
Eight sites recruited 54 children. The recruitment rate from those eligible was 94%, with the majority retained (74%). Candidate outcome measures were well completed, except for ICDAS. For 12 patients there was deviation from allocated treatment, with a tendency for more children to receive SDF than allocated. Interviews were conducted with 61 participants. Constructs from all CFIR domains were represented. Areas found to hinder SDF implementation were contracts, remuneration and licencing. SDF application not requiring restoration was simultaneously supportive and detrimental to implementation.
Discussion
SDF addressed an unmet need and facilitated the treatment of children in primary dental care. Interestingly, many teeth were restored following SDF application owing to concerns over social perceptions, efficacy and function. Lack of equipoise challenged the feasibility of a trial, leading to tension between adhering to randomisation and patient-centred care.

Conclusion
SDF was valuable for some children; nonetheless contractual arrangements are a barrier to implementation and future evaluation needs careful consideration.