Clinical Effectiveness of Silver Diamine Fluoride in Primary Dentition: A Systematic Review

¹DDS, DMD, FICD, FACD, FPFA — Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, USA. Position: Clinical Associate Professor, Director of Urgent Care Clinic. Department of General Dentistry

²BDS, DSc (Oral Biology), CAGS (Periodontology) — Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, USA. Position: Clinical Associate Professor, Chair Infection Control & EHS Committee. Department of General Dentistry

³DMD, CAGS (Pediatric Dentistry) — Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, USA. Position: Clinical Assistant Professor, General Supervisor Faculty. Department of General Dentistry

⁴DMD — Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, USA. Position: Clinical Associate Professor. Director, Group Practice Model and Pre-Doctoral Clinical Experience. Director, Department of Clinical Analytics. Department of General Dentistry

⁵BDS, MSD (Biomaterials), CAGS (Prosthodontics), DSc (Oral Biology) — Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, USA. Position: Chair, Department of General Dentistry; Clinical Professor of General Dentistry.

⁶DDS — Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, USA. Position: Dental Assistant. Department of General Dentistry

⁷DMD, MS — Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, USA. Position: Dentist

⁸Pre-dental student —institution: Southborough High School

Corresponding authors: Ana Keohane, DDS, DMD, FICD, FACD, FPFA — Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, USA. Position: Clinical Associate Professor, Director of Urgent Care Clinic. Department of General Dentistry.

Table 2: Summary of the 13 studies included in the qualitative synthesis.

Effectiveness of SDF for caries arrest

Across the included studies, 38% SDF consistently demonstrated effectiveness in arresting cavitated lesions in pediatric patients. In a multicenter, phase III, placebo-controlled trial conducted in the United States, Fontana et al. [4] analyzed 1,413 lesions among 599 of 680 enrolled children (ages 12–71 months) with severe ECC who completed a six-month interim exam; caries arrest was significantly higher in the SDF group than in the placebo group (54% vs. 21%, P<0.001), leading to early termination of the trial due to demonstrated efficacy. Milgrom et al. [11] similarly found that 72% of SDF-treated lesions were arrested after 14–21 days in 66 preschool children, compared with 5% in the placebo group.

Comparative studies also showed superiority of 38% SDF over alternative fluoride therapies. Fung et al. [5], found that 38% SDF achieved greater caries arrest than 12% SDF over an 18-month follow-up period in Hong Kong. Mabangkhru et al. [9], reported higher arrest rates with 38% SDF (35.7% of lesions) than with 5% sodium fluoride varnish (20.9% of lesions) after 12 months in Thailand.

Large community-based trials further supported the effectiveness of SDF. Gao et al. 6 reported sustained caries arrest over 30 months among 1,070 Hong Kong children with ECC receiving silver- and fluoride-based interventions, including SDF, with a mean of 3.6 ± 3.7 arrested surfaces per child. In the Caried Away school-based cluster-randomized trial, Ruff et al. [12] enrolled 2,998 U.S. schoolchildren with untreated dental caries, of whom 1,398 completed follow-up; SDF combined with fluoride varnish achieved a 56% caries arrest rate compared with 46% for sealants and ART with fluoride varnish, and 81% of children in the SDF group remained free of new caries compared with 82% in the control group indicating that SDF with fluoride varnish was noninferior to sealants and ART with fluoride varnish for both caries arrest and prevention. Ruff and Niederman 13 extended these findings to low-income rural schoolchildren in a pragmatic randomized trial, further supporting SDF effectiveness in underserved populations.

Influence of application frequency

Several studies evaluated whether treatment frequency influenced clinical outcomes. Schroth et al. [14] compared monthly, 4-month, and 6-month application intervals of 38% SDF among 84 Canadian children with 505 lesions and reported lesion arrest rates of 98%, 95.8%, and 72%, respectively, suggesting that shorter treatment intervals are associated with greater effectiveness. In contrast, Thakur et al. [15] reported that extending SDF contact time beyond 30 seconds did not significantly improve arrest outcomes, indicating that application duration and application frequency influence outcomes independently.

Restorative outcomes following SDF treatment

Jiang et al. [8] evaluated the use of SDF before ART in 194 Hong Kong children (101 receiving SDF prior to ART and 93 receiving ART alone) and found that prior application of SDF did not negatively affect restorative survival over a 24-month follow-up period. A subsequent secondary analysis by Jiang et al. [7] reported improved parental satisfaction and oral health-related quality of life among children receiving ART with prior SDF application compared with ART alone.

Safety and adverse effects

Duangthip et al. [3] followed 888 preschool children assigned to 12% or 38% SDF applied annually or semiannually and reported no serious adverse events over 30 months, with 799 children remaining in the study at follow-up. Minor adverse effects included transient tooth or gingival pain (6.6%), gingival swelling (2.8%), and gingival bleaching (4.7%), all of which resolved without lasting harm. The most common treatment-related effect across the included studies was permanent black discoloration of arrested carious lesions. Clemens et al. [1] similarly evaluated caregiver acceptance alongside clinical effectiveness, reinforcing staining as a key consideration in treatment planning.

Discussion

This systematic review found that 38% silver diamine fluoride (SDF) is an effective, minimally invasive option for arresting active caries in primary teeth in pediatric patients. Across the included studies, SDF consistently performed better than placebo, lower-concentration SDF, and sodium fluoride varnish, with more frequent applications generally producing stronger arrest outcomes. In relation to the original research question, the evidence supports the use of SDF as a practical approach to slow or halt caries progression and help retain primary teeth for a longer period, especially when conventional restorative treatment is difficult because of age, behavior, access to care, or treatment cost.

The findings also suggest that the clinical value of SDF extends beyond short-term lesion arrest alone. By stabilizing cavitated lesions, SDF may reduce pain, lower the immediate need for invasive procedures, and create an opportunity to preserve the function of primary teeth until normal exfoliation or until definitive restorative care becomes feasible. This is especially relevant in early childhood caries, where maintaining primary teeth supports mastication, speech development, arch integrity, and quality of life.

The observed effectiveness of SDF is biologically plausible and consistent with its known mechanism of action. Silver ions provide antibacterial effects, fluoride enhances remineralization, and the alkaline solution promotes protein coagulation within dentin, together limiting lesion progression [10]. The superiority of 38% SDF over lower concentrations suggests that a higher concentration of active ions produces a stronger caries-arresting effect, although this benefit must be weighed against more visible staining [5]. In addition, the better outcomes reported with shorter recall intervals indicate that SDF effectiveness is influenced not only by concentration but also by application frequency, which appears to play an important role in sustaining lesion arrest over time [14].

These findings are broadly consistent with, and extend, the existing literature on SDF. The reviewed studies confirm previous reports that SDF is superior to placebo and more effective than some fluoride-based alternatives for arresting dentin caries in primary teeth [4,9,11]. They also extend prior work by showing that SDF can be integrated into a broader minimally invasive care pathway: studies evaluating SDF before atraumatic restorative treatment found that pretreatment did not compromise restoration survival and may improve parental satisfaction and oral health-related quality of life [8,7]. This suggests that SDF should not be viewed only as a temporary or stand-alone measure, but also as part of a staged management strategy for children with a high caries burden.

The practical implications of these findings are important. 38% SDF appears particularly useful for young, anxious, uncooperative, medically compromised, or special healthcare needs children, as well as for children in underserved communities where access to traditional restorative care is limited. In such settings, SDF offers a low-cost, simple, and noninvasive method to control disease without local anesthesia, rotary instrumentation, or advanced clinical infrastructure. Its effectiveness in school-based and community programs further supports its value as a public health intervention that can expand access to care and reduce untreated disease burden [12,13]. Based on the findings of this systematic review, a clinical decision-making pathway is proposed to assist clinicians in determining when 38% SDF may be appropriate for the management of caries in the primary dentition (Figure 2).

Figure 2: Clinical decision-making tree for the use of 38% Silver Diamine Fluoride – Management of Caries in the Primary Dentition.

At the same time, the review highlights that clinical success does not automatically equal treatment acceptance. The most consistent drawback of SDF was permanent black staining of arrested lesions. Although this is not harmful and is primarily cosmetic, it remains a major factor influencing caregiver acceptance, especially for anterior teeth [2]. This means that the use of SDF in pediatric dentistry should be accompanied by clear communication with parents and caregivers regarding benefits, limitations, esthetic consequences, and alternative treatment options.

Several limitations of this review should be acknowledged. The included studies were heterogeneous in study design, sample size, follow-up period, comparator interventions, and application protocols, which limited direct comparison across studies and made a quantitative meta-analysis inappropriate. Follow-up durations varied considerably, with some studies reporting only short-term outcomes, which restricts conclusions about how long arrested lesions remain stable. In addition, the studies were conducted in different healthcare systems and populations, which may affect generalizability. Factors such as oral hygiene, dietary habits, baseline caries severity, and caregiver preferences were not uniformly controlled and may have influenced outcomes. An additional limitation is that the review focused specifically on 38% SDF in the primary dentition, which strengthens clinical relevance but narrows scope; conclusions should not be generalized beyond primary teeth or to other SDF concentrations without caution. Some included evidence, such as pragmatic or preprint data, also differs in level of maturity, which should be considered when interpreting the strength of the conclusions.

One of the more notable and somewhat unexpected findings was the apparent sensitivity of outcomes to reapplication intervals. While SDF is often discussed as an effective caries-arresting agent in general terms, the reviewed studies suggest that its success is more protocol-dependent than may be assumed. Markedly higher arrest rates with monthly or shorter-interval application compared with longer intervals indicate that the durability of its effect may decline when retreatment is delayed. However, this greater clinical effectiveness must be balanced against the additional cost and logistical burden associated with more frequent applications. Although SDF is generally considered a low-cost intervention, repeated visits increase material use, clinical time, caregiver time, transportation needs, and program-level costs, potentially reducing one of SDF’s principal advantages over conventional restorative treatment. This trade-off may be particularly important in public health, school-based, and outreach settings, where repeated follow-up can be difficult to sustain. Therefore, the optimal application schedule should consider not only caries-arrest effectiveness but also cost-effectiveness, feasibility, patient adherence, and access to follow-up care.

Future research should focus on longer-term outcomes to determine how effectively SDF helps maintain primary teeth until natural exfoliation, and on direct comparisons of application schedules to identify the minimum frequency required to sustain lesion arrest while remaining practical and cost-effective in real-world settings. Direct economic evaluations should compare the incremental benefit of more frequent SDF application with the added costs of additional clinical visits and follow-up. Additional work is also needed to explore methods for improving esthetic acceptability and caregiver acceptance, including communication strategies, shared decision-making tools, and adjunctive techniques aimed at masking or reducing discoloration. Finally, future studies should examine cost-effectiveness, quality-of-life outcomes, and implementation in diverse healthcare systems to better define the role of SDF in both clinical and community pediatric dentistry.

Overall, the evidence in this review supports 38% silver diamine fluoride as an effective and clinically meaningful option for arresting caries in primary teeth.  For many children particularly those at high risk or with limited access to care SDF represents an important tool for maintaining primary dentition and improving disease control in a practical, patient-centered manner until definitive care or natural exfoliation. For dental providers providing pediatric care, this study highlights that Thirty-eight percent of SDF can arrest active caries in primary teeth and may help retain affected teeth until definitive care or natural exfoliation. Application of the protocol matters: repeated application, with recall intervals selected according to lesion activity and patient risk, appears more effective than a single application. SDF is particularly useful for young, anxious, medically complex, or underserved children, but caregivers must be informed that arrested lesions become permanently black-stained. More frequent application appears to improve outcomes, and current evidence supports its use as part of a minimally invasive, evidence-based approach to pediatric caries management. While it does not restore tooth structure, it can help preserve primary teeth for longer by stopping or slowing disease progression, delaying invasive treatment, and supporting minimally invasive pediatric care. Its greatest strengths lie in accessibility, simplicity, and effectiveness, while its greatest limitation remains in esthetic staining. For many children particularly those at high risk or with limited access to care SDF represents an important tool for maintaining primary dentition and improving disease control in a practical, patient-centered manner until definitive care or natural exfoliation.

Conclusion

This systematic review supports the use of 38% silver diamine fluoride (SDF) as an effective, minimally invasive approach for arresting active dental caries in primary teeth, particularly when conventional restorative treatment is challenging or not feasible. Repeated applications appear to enhance caries-arrest outcomes, highlighting the importance of individualized recall intervals, regular reassessment of lesion activity, and consideration of each child's caries risk. SDF represents a valuable treatment option for young, anxious, medically complex, and underserved pediatric populations, potentially improving access to care while reducing the need for more invasive interventions. However, the permanent black staining of arrested carious lesions remains an important consideration and should be discussed with caregivers to support informed, shared decision-making. Overall, SDF is a valuable component of evidence-based, patient-centered caries management in pediatric dentistry.

Acknowledgements

The authors thank all individuals who contributed to the literature screening and review process.

Conflict of Interest statement

The authors declare no conflicts of interest related to this work.