Dental caries remains one of the most common chronic diseases of childhood, impacting both children’s oral health and overall health. Early childhood caries is a destructive model of tooth decay in young children, which can lead to pain and infection, in addition to eating and speech difficulties. Caries are widely spreading in children, and conventional surgical methods are associated with drawbacks, so interest has been raised in noninvasive concepts. Silver diamine fluoride (SDF) is one such alternative option that has recently gained tremendous popularity as a topical agent showing great promise in the prevention and arrest of caries, notably in primary teeth.^[1]

SDF is a simple, cost-effective agent composed of silver and fluoride ions, which act in concert to arrest active carious lesions and prevent further destruction.^[2,3] Silver ions can impart an antibacterial mechanism against cariogenic bacteria, and fluoride assists in the remineralization of demineralized tooth structures, which ultimately prevents caries progression.^[4] As a result, SDF has gained popularity in pediatric dentistry, especially in children with caries at an early stage and dental anxiety or who have limited access to restorative care through traditional means.^[5]

The top three benefits of SDF are that it is easy to use, noninvasive, and can halt or inhibit the progression of caries without the use of dental drills or anesthesia. Clinical studies have shown that SDF is very effective in arresting caries, especially in primary teeth, and is associated with a reduced need for restorative therapy.^[6,7] Furthermore, its affordability and the ability to apply it in a single session make it an attractive choice in resource-limited settings, where access to more conventional treatments may be restricted.^[8] However, despite these benefits, esthetic concerns related to the staining of treated teeth remain a notable limitation and may affect its acceptance among patients and caregivers.^[9,10] Figure 1 shows some characteristics of SDF in dental caries treatment.

This review aims to provide a current, comprehensive evaluation of the efficacy of SDF for the prevention and arrest of dental caries in children. It reviews the most recent research on SDF’s antibacterial capabilities, safety, and efficacy in the child population and how it can increase access to dental care in underprivileged areas. The review also explores the drawbacks and restrictions of SDF, especially esthetic issues and its long-term effects on tooth structure and function.

The SDF is easy to apply and nonintrusive. A patient is treated after her teeth are cleaned and dried. The process goes as follows: a tiny brush is used to apply a single drop of SDF to every affected tooth. After 1 min, the subject reacts with the tooth surface, and the tooth changes color from colorless to dark brown or black, indicating the arrest of carious lesions.^[11] SDF is an effective method in pedodontics as it not only arrests the progression of existing carious lesions but also acts as a preventive measure against new carious lesions.

The mechanism of action of the SDF is multifunctional and plays a crucial role in its efficacy in the treatment of carious lesions. The two active ingredients of SDF, silver ions and fluoride, have synergistic properties and impart several positive effects on dental tissues, as well as on oral microbial communities.^[12]

The ability of SDF to arrest dental caries in children has been investigated through research and clinical studies. Several studies show that a 38% SDF may be more effective in stopping cancer progression. SDF is mainly used for patients with high caries susceptibility, which often includes patients from developing countries or deprived regions. On the other hand, untreated SDF repeated applications could effectively reduce the development of new carious lesions caused by risk factors such as poor oral hygiene, high sugar intake, or low socioeconomic conditions in children with a higher risk of caries.^[36,37]

Research indicates that SDF is especially beneficial in the initial phases of caries development, including white spot lesions, as it facilitates remineralization and stops the progression of the disease. Moreover, SDF has been shown effective in arresting cavitated lesions in primary teeth. Although SDF does not rebuild tooth structure, it prevents further decay, thereby reducing the risk of pain and potential infection. Previous reviews have emphasized the efficacy of silver compounds in controlling dental caries through prevention and arresting lesions in primary and permanent dentition.^[38-40]

SDF, as an alternative treatment modality, offers a noninvasive, cost-effective, and easy way to treat dental caries. A community-friendly solution through gamification would pose a less scary, anxiety-provoking proposition, especially for the younger audience.^[41] Studies show that the caries-arresting properties of SDF may last up to 1 year or more after a single application. However, for maintenance of efficacy, where children are at an increased risk of caries, multiple applications may be required.^[42]

Tooth decay in early childhood often advances quickly in primary teeth, making treatment efforts difficult. SDF has been effective at arresting caries progression, and published research data demonstrate high arrest rates, particularly with a 38% solution. Biannual applications give better results than annual applications, and results on mandibular anterior teeth are also usually better than maxillary posterior teeth.^[43] Compared to sodium fluoride (NaF) varnish, SDF is more effective in dentin caries arrest; however, the outcome can depend on factors including size of the lesion, time of exposure, diet, and oral hygiene habits.^[44,45] Some studies suggest that teeth with higher plaque accumulation as well as children fed with milk or snacks frequently have a lower rate of caries arrest. Moreover, it has been found that the benefits of SDF exceed some restorative materials like glass ionomer in preventing the advancement of dentin caries. SDF provides an effective means to arrest the progression of dental caries in children with multiple carious lesions without resorting to invasive treatments at an early stage. This approach reduces the likelihood of necessitating more comprehensive and complex dental procedures in future.^[46] Tooth pits and fissures are more prone to caries development than smooth surfaces due to their morphology and restricted accessibility for cleaning. Due to its antibacterial and remineralizing properties, SDF has been found effective in denoting caries in pits and fissures. It can also be used as an alternative to sealants, especially for children who cannot undergo proper sealant application procedures. Nonetheless, the dark staining caused by SDF in these regions may sometimes be confused as an initial lesion, which may result in a diagnostic challenge.^[27] Table 1 summarizes some recent clinical trials on the use of SDF in the management of dental caries.

SDF is further employed in the management of dental hypersensitivity as well as symptomatic teeth with molar incisor hypomineralization. Several studies have documented that silver ions occlude dentinal tubules by protein precipitation.^[55] Moreover, calcium fluoride and silver iodide formation through SDF promote dentinal tubule sealing and dentinal tubule patency reduction. While SDF has been approved for treating dentine hypersensitivity, there is insufficient robust evidence from randomized trials or systematic reviews to confirm its effectiveness in this application. In pediatric dentistry, managing extensive caries presents a significant challenge. This condition, frequently observed in children with poor oral hygiene or those affected by severe systemic illnesses, involves decay in multiple teeth that are typically caries-resistant.^[56] Although fluoride-based products such as NaF effectively prevent caries, they fail to arrest caries progression in dentine.^[57] SDF is a new alternative to aid in the management of extensive carious lesions, as it terminates the spread of carious lesions without needing invasive surgery to treat the affected tooth, thereby preventing the spread of infection. This makes it especially beneficial for young children and patients with systemic diseases who could greatly benefit from its known efficacy and tolerability in these groups.^[58]

SDF acts as both an independent therapeutic modality and also as an adjunct treatment alongside restorative procedures, where it can be applied prerestoration placement. The integration of SDF with atraumatic restorative treatment (ART) is occasionally designated as silver-modified ART (SMART) restoration or SMART Hall when utilized in conjunction with the Hall technique. This approach can be implemented either immediately preceding restoration placement or after SDF application, allowing time for carious lesions to arrest, sensitivity to diminish, or for the patient to acclimate to the dental environment.^[59] The application of SDF before the placement of restorations can reduce the risk of sealed carious lesions evolving into irreversible pulpitis or even a dental infection. However, there is currently a lack of randomized controlled trials comparing the effectiveness of SMART to other restorative approaches.

The main benefit of SDF is that it is noninvasive and, therefore, there is no need for traditional surgical procedures such as tooth extraction and restoration. This feature is particularly useful for children with behavioral problems or patients with special healthcare needs because it reduces the use of complex pharmacologic behavior management techniques, such as sedation or general anesthesia, which carry increased health risks.^[41]

The application of SDF is quick, taking only 60 s on average, and requires less specialized training than conventional restorative procedures. Registered nurses, in some jurisdictions, can administer SDF with the direction of licensed dentists, leading to greater healthcare access for the underserved population.^[56,60] This simplified model facilitates the application of SDF in public health, which advances the goals of chronic disease management and dental health equity.^[61,62]

SDF application can be much more economical than the costs associated with dental surgery. SDF can reduce the need for expensive restorative treatment by arresting caries progression, improving the overall cost-effectiveness of dental care.^[63] This makes SDF an appealing choice for both dental professionals and patients, as it can result in substantial long-term cost savings and improved health outcomes.

The SDF technique eliminates the need for drilling and anesthesia while requiring minimal cooperation from patients. This makes it an ideal choice for treating very young children, individuals with disabilities, and those who experience dental fear or anxiety.^[64]

Various safety concerns and adverse events related to SDF use have been reported. Some studies demonstrated that the most common adverse event was the darkening of carious portions, which was mainly well-audience accepted by adults and children,^[63,65] and it was found that only ~7% of patients were concerned about the staining. Adverse events reported to the Food and Drug Administration (FDA) are classified as either suspected adverse reactions (meaning that the drug would have a reasonable chance of causing the event) or serious adverse events (resulting in death, hospitalization, or life-threatening conditions).^[65] Many studies identified some relatively mild adverse events such as xerostomia, gingival pain, inflammation, and transient gastrointestinal disturbances, but severe ones have not been consistently observed.^[64] In particular, short-lived reactions such as metallic taste, temporary discoloration of the skin, and irritation of the oral mucosa were reported, all of which usually disappeared within days.^[62] According to FDA reports, these side effects are typically not a concern, as the benefits of stopping tooth decay with SDF usually outweigh cosmetic considerations. Healthcare providers are advised to inform patients about potential staining before treatment, preferably using pre- and posttreatment images of treated teeth to set appropriate expectations.^[63] In addition, the FDA has approved off-label use of SDF for the arrest of caries, enhancing its safety profile when applied according to protocol.^[63] To reduce risk, SDF should not be put on exposed pulp, and patients with deep cavities should be carefully followed up.^[62] The serum fluoride concentration achieved after SDF application is below the oral reference dose set by the US Environmental Protection Agency indicating a low risk of toxicity.^[63] However, since SDF does not reconstruct tooth structure, it may not be appropriate for children with significant decay or cases needing an esthetic response. In these cases, regular restorations may still be required. While many studies have shown positive short-term outcomes with SDF, additional long-term studies are necessary to fully explore its potential and duration of action to prevent and arrest caries over months/years.^[6,9]

The choice of SDF application methodology (light-curing vs. conventional) is determined by individual preference and clinical context. Research indicates that most practitioners prefer the light-curing technique, with advantages such as a shorter treatment time and results available immediately. Still, several dentists have questioned this approach and simply lack consensus and limit scientific results validating this approach.^[66]

In pediatric dentistry, SDF is one of the highly effective, noninvasive, economical, and safe approaches for caries prevention. Its use is particularly beneficial for young children, high-risk population, and individuals with limited access to dental care. Despite worries about esthetic discoloration, SDF remains an essential tool in the armamentarium of pediatric dentistry for caries prevention and management of caries in primary teeth. Therefore, in light of its promising results, further studies and refinements of its application techniques may broaden its use and consequently its acceptance.