Silver diamine fluoride (SDF) is a clear, odourless liquid indicated for desensitisation of non-carious tooth lesions and molar incisor hypomineralisation. It is also useful for arresting carious lesions in adults and children who are high caries-risk and/or have difficult-to-control, progressing carious lesions, those who are unable to tolerate invasive treatment, elderly populations, and those who are medically compromised or have additional care and support needs. SDF may be used to manage lesions that are too extensive to restore but not associated with pain and/or infection. This can be important particularly where extractions might be contra-indicated for medical or behavioural reasons. This paper summarises the global evidence for the effectiveness and safety of SDF, describes what it is, its mechanisms of action and presents recommendations on how to use it. There are details on indications/contra-indications and risks/benefits to be considered in the use of SDF also discussion of how to approach SDF's side effect of black staining of carious tooth tissue. We give an example of an information sheet (Appendix S1, see online supplementary information) that may be used when discussing SDF with patients, particularly for primary teeth in children, but adaptable for the permanent dentition and for adults.