Carious tissue is not removed at all. To minimise droplet and aerosol production, the surface is dried with cotton instead of compressed air, then SDF is applied using a micro brush. Arresting lesions using SDF can provide a solid foundation for restorations53,54 and can be combined with ART in primary or permanent teeth or the HT. There are currently no clinical trials of efficacy, so combinations may be thought of as a 'belt and braces' approach to synergise the benefits of both treatments.