Dental is a disease process that is multifactorial, dynamic, and irreversible that occurs due to an imbalance between host and ecological factors (1). The epidemiological studies confirm that early childhood caries remains a significant disease burden in both developed and developing countries, along with high unmet dental needs (2). The reasons for the unmet dental needs could be poor access to resources, financial constraints, the higher cost of dental treatment, lack of awareness, and their general health, and education opportunities (3). The traditional treatment for a carious tooth is to remove the infected, irreversible, and demineralized dentin by mechanical excavation and restore it with a restorative material (4). In young children, behavior issues routinely complicate or prevent the restorative treatment. This unmet treatment needs lead to progression of the carious lesion and pain in some cases, which has a fatalistic impact on quality of life. Arresting the carious lesion has been proposed in children with uncooperative behavior and disadvantaged low socioeconomic communities (5).

Silver diamine fluoride (SDF), a colorless liquid with a pH of 8 to 9 and the ability to remineralize minerals, is utilized as a caries arresting agent in dentinal caries lesions in children. In the late 1970s, SDF was initially used in Japan but was not that popular. However, in the beginning of the 21st century, it has gained popularity in China as a dental caries arresting agent (6, 7). It has recently become popular and available in the United States and South Asian countries. Other silver products like silver fluoride and SDF in different concentrations are commercially available in Austria, Argentina, and Brazil these days (8, 9). SDF is most commonly used in a concentration of 38% solution containing 44,800 parts per million (ppm) of fluoride. It is also available in 30% containing 35,400 ppm and 12% containing 14,150 ppm of fluoride, respectively (10). The caries arresting efficacy of dental caries was reported to be 65.9% by 38% SDF (11). The primary drawback of SDF is the black discoloration of dentinal carious tissue following application due to the oxidation process of silver ions, along with a few other reversible modifications such as oral tissue staining and ulceration (12). This page provides information on this intriguing substance, including how it can be used to treat and prevent dental problems in both primary and permanent teeth.

Although silver compounds were used to prevent dental caries, in Japan, it was customary for women to “Ohaguro,” or color their teeth black, to signify their marital status 1,000 years ago (13). Around 1,000 B.C., the first medicinal use of silver compounds was to treat various infections. In medical science, silver-based materials such as silver foil, silver nitrate, and silver sutures have been employed (14). Von Hofmann discovered silver nitrate to be a highly powerful antibacterial agent (Naegeli) (15). In 1891, Stebbins used silver amalgam and nitric acid for the first time in dentistry, and found caries inhibition in the subsequent follow-ups (16). “Howe’s solution” consisting of silver nitrate was used directly on caries lesions and similar results were found by Howe et al. (17). Since then, it has been used for caries arresting solution.

The first time silver fluoride was applied in dentistry was in the early 1970s (18). Stannous fluoride (SnF₂) must be used as a reducing agent for applying silver fluoride, a colorless, alkaline liquid that contains active silver, and fluoride ions. SDF has been approved as a therapeutic agent by the Central Pharmaceutical Council of the Ministry of Health and Welfare, Japan dentistry (19). SDF is a stable chemical compound, not as alkaline as silver fluoride (at a pH of 8–9), and does not require a reducing agent like silver fluoride. Practitioners in Southern California used SDF in preschool children with nursing bottle caries (20). Many community projects were planned in sub-Saharan Africa, Cuba, and several African countries using SDF as a caries-arresting agent (5). During this time, SDF is used quite seldom, and there has been limited research regarding its effectiveness. SDF has been used to stop tooth cavities in various nations, including China, Japan, the United States, and South Asian nations, at a concentration of 38%.

According to research (Lansdown), silver interacts with sulfhydryl groups on proteins or DNA to block respiratory processes, change hydrogen bonding, affect the formation of cell walls, unwind DNA, and affect cell division at the microcellular level (21, 22). Bactericidal activity and biofilm formation inhibition are produced by these interactions (23). Shimizu and Kawagoe outline three potential modes of action (24). Figure 1 illustrates the many therapeutic consequences of SDF.

The main disadvantage and concern of SDF are black discoloration and metallic taste, so some parents and their children may not accept the treatment outcome. When SDF was applied to the carious dentin, insoluble yellow-colored silver phosphate was formed (51), which later turns to black when exposed to sunlight or due to the influence of reducing agents. Knight et al. suggested application of after using SDF, potassium iodide is used to remove the black discoloration. Crystals of creamy white silver iodide are created when potassium iodide combines with the remaining free silver ions. As a result, there are no longer any free silver ions that may interact with sulfur to produce black precipitates (52).

SDF also has a metallic taste, which is unacceptable to the children, and parents. Sometimes gingival and mucosal irritation can occur, which is transient in nature and the tissue affected turns white and heals within 1–2 days. Thus, use of a rubber dam or a separating medium like vaseline or cocoa butter should be used before using the SDF solution near to the gingiva (13).

Crystal et al. evaluated the parental acceptance and perception of SDF staining and observed that staining was more acceptable on posterior teeth compared to anterior teeth. Most parents preferred SDF application compared to treatment under deep sedation or general anesthesia (53). In a different research, Alshammari et al. discovered that the majority of the parents disapproved of the SDF application. The authors came to the conclusion that dentists should offer informed consent forms with unambiguous photos while treating anterior teeth showing expected staining (54).

SDF has been proven to be an effective therapeutic agent in arresting dental caries in both primary and permanent teeth. It also helps in reducing dentinal hypersensitivity, remineralizing properties, antimicrobial activity, and antifungal potency. Furthermore, SDF is a simple, easy to use, easily affordable, and widely available therapeutic agent in developing countries. Though it has the disadvantage of black staining and metallic taste, more studies would be needed to prove SDF as a material of choice in the current scenario.

NK and RK contributed to concept designing, searching the literature, and writing the review manuscript. Both authors contributed to the article and approved the submitted version.