Demineralization of teeth or caries is a common health problem among pediatric patients. It is a more serious issue among children from low-income households due to their lack of access to proper dental care. Silver diamine fluoride (SDF) is an effective agent used to treat demineralization, but experiments are being done to replace it with nanosilver fluoride (NSF). The purpose of this study was to assess the effectiveness of nanosilver fluoride varnish in containing demineralization of primary teeth. A systematic literature review method was used. About 15 articles met the inclusion criteria. Findings are conflicting, but most of the reviewed studies confirmed the effectiveness of an agent with nanoparticles compared to all other alternatives, especially SDF. Apart from suppressing microorganisms that cause demineralization at very low concentrations, agents with nanoparticles protect patients from discoloration of teeth and formation stains. Nanosilver fluoride varnish can be used to replace the current alternatives, but the findings should be used with caution since most of the present studies are experimental.