ObjectivesTo assess if using potassium iodide (KI) immediately after application of silver diamine fluoride (SDF) significantly reduces the staining of tooth structure.Data source and selectionFour online databases (OVID, Scopus, PubMed and Google Scholar) were searched (June 2019). Additional studies were sought through grey literature search and hand searching the reference list of included articles. All studies that analysed the effect of KI on SDF staining of tooth structure with access to full text in English language were included.Data synthesisOf the six articles included in the review, five reported stain reduction in the teeth treated with application of KI to carious tooth structure following the application of SDF while one article reported no significant beneficial effect on reducing staining, when compared to SDF alone. Of the materials selected to restore SDF + KI treated teeth, resin‐modified glass ionomer was found to produce the lightest results, followed by glass ionomer cement and composite resin. An in vivo case report also revealed some staining after six months, even with SDF + KI treatment.ConclusionsAlthough some studies reported a positive effect, insufficient evidence exists supporting a tangible clinical benefit of SDF + KI treatment on the tooth staining, mainly due to methodical variations within the current literature.