Silver diamine fluoride versus atraumatic restorative treatment for management of childhood caries: a systematic review and meta-analysis

Abstract

Objective

This systematic review and meta-analysis aimed to assess the efficacy of Silver Diamine Fluoride (SDF) in comparison with the standard Atraumatic Restorative Therapy (ART) in arresting dental caries in children.

Methods

We searched the databases of CENTRAL, Embase, PubMed, and Scopus till 16 August 2025. Eligible studies were randomized controlled trials (RCTs) comparing SDF alone vs. ART alone for caries arrest in pediatric patients with at least 12 months of follow-up. Risk ratio (RR) was calculated in a random-effects meta-analysis model. Subgroup analysis was conducted based on the frequency of SDF application and follow-up. Cochrane Collaboration risk of bias-2 tool was used to assess risk of bias. The review was registered on PROSPERO database (CRD420251127028).

Results

Eight RCTs were included. All were parallel-arm studies. Comparing data of 6430 teeth or surfaces treated with SDF with 5466 teeth or surfaces treated with ART, the meta-analysis showed that SDF had marginally but significantly higher caries arrest rate as compared to ART (RR: 1.21 95% CI: 1.02, 1.44 95% I²: 96%). No publication bias was noted. Results lost significance during sensitivity analysis. Results also turned non-significant on both subgroup analyses based on the frequency of SDF application and follow-up.

Conclusions

Very low-quality evidence suggests that SDF may be marginally better than ART at arresting dental caries in children. Evidence must be interpreted with caution given the high heterogeneity, methodological concerns in included studies and the lack of robustness of results during sensitivity and subgroup analyses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-026-07741-9.

Introduction

Dental caries remains one of the most prevalent chronic diseases affecting children worldwide, encompassing both early childhood caries and caries occurring in older children and adolescents [1]. It is a multifactorial condition caused by cariogenic microorganisms, frequent consumption of sugar, poor oral hygiene, and social-behavioural factors [2, 3]. If left untreated, carious lesions may progress from initial demineralization to cavitation, pain, infection, and functional impairment, adversely affecting nutrition, growth, school performance, and overall quality of life [4, 5]. Importantly, childhood caries is associated with an increased risk of caries in the permanent dentition and long-term treatment is often needed [2, 3]. Contemporary management strategies therefore emphasize early detection, prevention, and minimally invasive approaches aimed at arresting disease progression and preserving tooth structure across the pediatric age spectrum [6].

Traditionally, dental cavities are treated surgically by trained professionals using specialized equipment. However, treating young children is often hindered by dental anxiety and fear. To address this, advanced behavior management techniques like sedation and general anesthesia are used, but these increase treatment costs and pose greater risks for both the patient and the dentist [7]. The advent of Minimal Intervention Dentistry (MID) has brought about a significant change in how dental caries are managed, especially in young children. It encompasses atraumatic restorative therapy (ART) and silver diamine fluoride (SDF), both aimed at preserving teeth as much as possible while minimising the psychological impact on the patient [8, 9].

Silver diamine fluoride (SDF) is a topical treatment used to address dental caries, especially in young children and those with limited access to conventional care options [10]. It combines the antibacterial effects of silver with the remineralizing benefits of fluoride, offering a simple, non-invasive, and cost-effective solution for treating dental caries. This is especially useful for very young children who do not respond well to dental procedures and need minimal manpower training [10]. Conversely, ART involves removing decayed tissue with hand instruments, then filling the cavity with an adhesive material, usually glass ionomer cement (GIC). This minimally invasive and cost-effective technique decreases dental anxiety, is well-liked by children, provides an effective seal, and substitutes the damaged tooth structure [11]. Comparing SDF with ART is vital for clinical decisions because both are key minimally invasive methods for treating childhood caries, especially when traditional restorative options are limited or impractical. ART aims to arrest disease through selective caries removal, but its success depends on factors such as operator skill, child’s cooperation, lesion size, and restoration retention, particularly for anterior or multi-surface lesions [12, 13]. Conversely, SDF is a quick, non-invasive, chairside agent that does not require drilling or sealing cavities, making it suitable for uncooperative children or community settings [8]. Although these practical differences exist, both treatments are recommended in current caries management guidelines. They differ significantly in their biological mechanisms, treatment complexity, resource needs, and aesthetic results. A direct comparison of SDF and ART is essential for evidence-based treatment selection across diverse pediatric populations.

In recent times, the efficacy of SDF vs. GIC has been debated in the dental literature, with several studies comparing their ability to arrest dental caries [14]. Previous reviews have either compared SDF with varying interventions [15] or examined the efficacy of SDF with ART vs. ART alone for childhood caries [16]. Only two prior systematic reviews by Wakhloo et al. [14] and Warthington et al. [15] have exclusively compared SDF with ART but with the inclusion of only two and four studies respectively. Another review by Zaffarano et al. [10] has also compared SDF with different interventions, but they could include only three studies using ART in the control group. Given the publication of new studies in literature, there is a need to for more updated evidence. Hence, we conducted the present systematic review and meta-analysis to compare the efficacy of SDF vs. ART in arresting dental caries in children.

Methods

Registration and reporting

The Cochrane Handbook [17] and the PRISMA guidelines [18] were consulted for the conduct of this systematic review. This systematic review and meta-analysis were prospectively registered in the PROSPERO database (CRD420251127028). PRISMA checklist is attached as Supplementary File 1.

Eligibility criteria

Studies were eligible if they met the following PICOS criteria: (1) Population: pediatric patients (≤ 18 years) with active dental caries; (2) Tooth type: primary teeth, permanent teeth, or mixed dentition, provided outcomes were reported at the tooth or tooth-surface level; (3) Lesion type: active carious lesions involving enamel or dentine, including both non-cavitated and cavitated lesions, without clinical or radiographic signs of pulpal involvement; (4) Interventions and comparators: SDF (any concentration or application frequency) compared with ART using GIC; and (5) Outcome: caries arrest or disease control, defined as lesion inactivation without progression, symptoms, or need for further operative intervention. For ART, treatment success was accepted as defined by the original studies and typically included intact or clinically acceptable restorations accompanied by absence of caries progression or symptoms. (6) Study type eligible were randomized controlled trials (RCT) only (parallel, split-mouth, and cluster study design).

Exclusion criteria were:

1.  Studies using SDF or ART on non-carious teeth.

2.  Studies on adult populations.

3.  Studies combining SDF with other caries arrest techniques.

4.  Follow-up of < 12 months.

5.  In-vitro studies, review articles, editorials, and letters to the editor.

Search strategy

The literature search was conducted by two independent reviewers (TM and WW), who evaluated all publications for eligibility. A comprehensive search was performed in the CENTRAL, Embase, PubMed, and Scopus databases for all relevant studies, without language restrictions. Search phrases included both free-text and Medical Subject Headings, combined to create targeted search queries. Supplementary File 2 details the search methodology. The search concluded on 16 August 2025. Google Scholar and Clinicaltrials.gov were also searched to identify any missed trials. Additionally, we hand-searched the reference lists of included studies and prior reviews for any further relevant research.

Selection of studies

The research articles were selected after a comprehensive evaluation of the search results, which involved initial deduplication followed by screening of titles and abstracts. Both reviewers compared the study titles and abstracts to the eligibility criteria before selecting articles for further review. The selected articles were then subjected to a full-text assessment, and only those agreed upon by both reviewers were included in this review. Disagreements were resolved through a predefined consensus process that involved rechecking the original articles against the eligibility criteria, followed by discussion until agreement was achieved. As only two reviewers were involved in this study, no third reviewer was used for adjudication.

Data management

Data obtained from the studies included: author, year of publication, type of study, included population, intervention, control group protocol, sample size, number of teeth, age range of patients, any additional caries control measures, criteria for arrest, follow-up and outcome data. Data was obtained by two reviewers and compared for any errors. Studies with missing outcome data were included in the systematic review but not in the meta-analysis.

Risk of bias assessment

The quality of included studies was judged by the Cochrane Collaboration risk of bias-2 tool [17]. Studies were judged for the randomization process, deviation from intended intervention, missing outcome data, measurement of outcomes, selection of reported results, and overall risk of bias. Two independent reviewers assessed the quality for each domain. Discrepancies were then resolved by discussions.

Statistical analysis

Both qualitative and quantitative analysis of outcome data was conducted. Statistical analysis was done on the “Review Manager” (RevMan, version 5.3). Caries arrest rates were compared between SDF and ART groups to generate summary estimates as Risk ratio (RR) and 95% confidence intervals (CI). The analysis was performed in a random-effect model. The chi-square-based Q statistics and I² statistics were used for inter-study heterogeneity. A p-value of < 0.10 for Q statistic and I² > 50% meant substantial heterogeneity. Publication bias was assessed by determining the symmetry of funnel plots and Egger’s test. Sensitivity analysis was performed by omitting one study at a time from the meta-analysis and regenerating the results. Subgroup analysis was conducted based on frequency of SDF application and follow-up. P values < 0.05 were considered statistically significant. Certainty of evidence was assessed using the GRADE approach.

Results

Search results

The detailed process of study selection and screening is shown in Fig. 1. We retrieved 417 studies from the databases. No additional studies were found from other sources. After removing duplicates, 154 articles remained. However, only 22 of these were chosen for further full-text review. Of these, eight studies [19–26] met the inclusion criteria.

Fig. 1.

Study flowchart

Characteristics of included studies

Study details obtained by the reviewers are presented in Table 1. All RCTs were parallel-design and conducted in pediatric populations aged 2 to 13 years. The publication year of the studies ranged from 2009 to 2025. Four trials [19, 21, 24, 25] were from Brazil, while others were from China [26], the USA [20], Egypt [23], and Saudi Arabia [22]. All except for two studies [20, 25] were conducted on primary dentition. One trial of Braga et al. [25] was conducted on a pediatric cohort of erupting permanent first molars while another study of Ruff et al. [20] included both primary and permanent dentition. Participant age ranged from 2 to 13 years. The protocol for SDF application differed across trials, including SDF concentration and application frequency. In three of the trials [22–24], SDF was applied biannually while in others only a single application was used. SDF concentrations ranged from 10% to 38%, with 30% and 38% being the most commonly used formulations. Before application, affected tooth surfaces were generally cleaned using cotton pellets or toothbrushes to remove gross debris, followed by isolation with cotton rolls or saliva ejectors to minimize moisture contamination. Surrounding soft tissues were routinely protected with petroleum jelly to prevent staining or irritation. SDF was applied directly to carious lesions using cotton pellets, micro-sponge brushes, or microapplicators, with contact times ranging from 30 s to 3 min. All trials used GIC for ART. Oral hygiene instruction, diet recommendations, and fluoridated toothpastes were provided to both groups in many of the included trials.

Table 1.

Details of included studies

Study & location	Design	Included population	Intervention (I) protocol	Control (C)	Sample size	Number of teeth	Age (years)	Additional measures for both groups	Criteria for arrest	F/U
Braga 2009; Brazil [25]	Parallel	Erupting permanent first molars with active initial caries without cavitation on occlusal surfaces	10% SDF applied to selected erupting molars with small cotton pellets for 3 min. Teeth were then washed with a 30-second water spray. Teeth were isolated from saliva with cotton rolls, and mucosa near the treated tooth was protected with petroleum jelly to avoid staining. The application was repeated twice, with an interval of 1 week.	ART using GIC (Vidrion F, SSWhite, Rio de Janeiro, Brazil)	I: 48 C: 43	I: 183 C: 162	5–7	Fluoridated paste	No increase in caries activity and retention of sealant	30 m
Santos 2012; Brazil [19]	Parallel	Primary posterior teeth with active caries lesions involving one or multiple surfaces at the dentine level	Annual 30% SDF application. Cotton rolls to isolate the teeth from saliva. Vaseline was applied to the soft tissues. SDF solution was left in contact with the tooth surface for 3 min.	ART using GIC (GC FUJI IX GP, GC America, Inc.)	I: 48 C: 43	I: 183 C: 162	5–6	Tooth-brushing sessions, Fluoridated paste, healthy eating instructions	I: dentine could not be penetrated by the probe and absence of symptoms ; C: presence of GIC	12 m
Zhi 2012; China [26]	Parallel	Primary teeth with active caries lesions involving one or multiple surfaces at the dentine level	Annual 38% SDF application. Detailed procedure not described.	ART using GIC annually (Fuji VII, GC Corporation, Tokyo, Japan)	I: 71 C: 72	I: 218 C: 262#	3–4	None	Dentine could not be penetrated by the probe and absence of symptoms	24 m
Vollu 2019; Brazil [21]	Parallel	Primary teeth with occlusal caries	Once 30% SDF application. Occlusal surfaces were cleaned with toothbrush; skin and gums were protected with petroleum jelly to avoid staining; tooth was isolated with cotton rolls and saliva ejector; tooth surface was dried followed by SDF application for 3 min. Excess was removed and tooth was rinsed.	ART using GIC (Ketac Molar Easy Mix 3 M ESPE)	I: 34 C: 33	I: 65 C: 52	2–5	Oral hygiene and diet recomm-endations	No change in ICDAS score and absence of symptoms	12 m
Abdellatif 2021; Saudi Arabia [22]	Parallel	Primary asymptomatic tooth with active dentinal occlusal/ labial lesions	Bi-annual 38% SDF application. The surrounding gingival tissues and lips were protected with petroleum jelly to avoid staining and irritation, the affected tooth was isolated and kept dry with cotton rolls and saliva ejectors, SDF was applied with a micro-sponge directly to the affected tooth surface(s), allowed to soak in for 2 min.	ART using GIC (GIC- Fuji IX, GC America Inc. IL, USA)	I: 45 C: 45	I: 121 C: 116	3–8	Oral hygiene and diet recomm-endations	Dentine could not be penetrated by the probe, no change in ICDAS score, and absence of symptoms	12 m
El-Ghandour 2024; Egypt [23]	Parallel	Primary teeth with occlusal caries	Bi-annual 38% SDF application. Gross debris was removed with cotton pellets; cotton rolls were used to protect surrounding tissues; affected tooth surfaces were dried with a gentle flow of air; SDF was then applied using a micro sponge brush; if the behaviour allowed, the SDF was left to dry for 1 min or it was covered with petroleum jelly to avoid being washed away.	ART using GIC (GC Fuji IX, GC America)	I: 50 C: 50	I: 268 C: 286	2–5	Oral hygiene and diet recomm-endations	Dentine could not be penetrated by the probe; ART evaluation criteria, and absence of symptoms	12 m
Rodrigues 2025; Brazil [24]	Parallel	Primary teeth with occlusal caries up to dentine	Bi-annual 38% SDF application. Occlusal surfaces were cleaned with toothbrush; skin and gums were protected with petroleum jelly to avoid staining; tooth was isolated with cotton rolls and saliva ejector; tooth surface was dried followed by SDF application for 3 min. Excess was removed and tooth was rinsed.	ART using GIC (Ketac Molar Easy Mix 3 M ESPE, Sumaré, Brazil)	I: 59 C: 59	I: 59 C: 59	2–5	Oral hygiene and diet recomm-endations	Dentine could not be penetrated by the probe and absence of symptoms	24 m
Ruff 2025; USA [20]	Parallel	Primary and permanent teeth with caries up to dentine	Once 38% SDF application. SDF application used a microapplicator after quadrant isolation with gauze and cotton rolls. Silver diamine fluoride was applied for a minimum of 30 s, and treated sites were then air dried for a minimum of 60 Seconds.	ART using GIC (type not reported)	I: 861 C: 807	I: 5651 C: 4647#	5–13	Fluoride varnish	Absence of caries recurrence	48 m

SDF Silver diamine fluoride, GIC Glass ionomer cement, ART Atraumatic restorative treatment, F/U Follow-up, m months, I Intervention group (SDF), C control group (ART)

^#Number of tooth surfaces

While all studies focused on treatment effectiveness by measuring caries arrest as the main outcome, a large cluster-RCT by Ruff et al. [20] examined caries recurrence after treatment. This study was included because caries recurrence is essentially the opposite of sustained caries arrest and indicates a failure to keep the lesion inactive during follow-up. Both outcomes evaluate disease control at the tooth or surface level and reflect the same underlying clinical concept, the intervention’s capacity to prevent the progression or reactivation of carious lesions. Criteria for caries arrest in the remaining studies were broadly comparable across trials and generally included lesion hardening on probing, absence of symptoms, stability of International Caries Detection and Assessment System (ICDAS scores), or lack of caries progression or recurrence. In the case of the ART group, the restoration was to be intact or in case of loss, there was no active caries. The follow-up of four studies [19, 21–23] was 12 months while for the remaining studies [20, 25, 26] it ranged from 24 to 48 months.

Qualitative assessment

Dos Santos et al. [19] examined underprivileged Brazilian schoolchildren aged 5–6 years and demonstrated significantly higher caries arrest rates with annual 30% SDF compared with interim restorative treatment using GIC at 12 months, with differences already evident at earlier follow-up intervals. In contrast, Zhi et al. [26], in a three-arm RCT among Chinese preschool children aged 3–4 years, reported high caries arrest rates across all treatment groups, including annual SDF, semi-annual SDF, and annual high-fluoride GIC. Semi-annual SDF achieved the highest arrest rate at 24 months, while annual GIC showed arrest rates comparable to annual SDF. Vollu et al. [21] evaluated preschool children with occlusal dentine caries in primary molars. They found no statistically significant differences between 30% SDF and ART in the proportion of arrested lesions at 12 months. Arrest rates remained high in both groups across multiple follow-up points, although treatment time was significantly shorter for SDF. Similarly, Abdellatif et al. [22] reported no significant differences in caries arrest between biannual 38% SDF and ART at 6- and 12-month follow-up in children aged 3–8 years, while demonstrating substantially reduced chair time with SDF. Rodrigues et al. [24] also observed comparable arrest rates between 30% SDF and ART at 12 months in preschool children, with both interventions maintaining high arrest rates over longer follow-up, and consistently shorter treatment times for SDF. ElGhandour et al. [23] reported markedly higher caries arrest rates with biannual 38% SDF compared with ART in preschool children with early childhood caries, with this difference observed for both anterior and posterior teeth. Improvements in oral health–related quality of life were reported in both groups without significant between-group differences. Ruff et al. [20] in a large school-based cluster RCT with follow-up extending up to four years, demonstrated similar surface-level caries control between SDF and ART. While recurrent surface failure risk did not differ significantly between treatments, a lower proportion of children treated with SDF experienced at least one failure episode during follow-up. Only one study of Braga et al. [25] could not be included in the meta-analysis as data were not presented as caries arrest rate per group. The outcomes were assessed as mean dental caries scores which were similar in both groups at baseline. On completion of 30 months of follow-up, the mean dental caries score was 1 in SDF group and 1.3 in the ART group with no statistically significant difference.

Meta-analysis

Data for the meta-analysis were available from seven studies. Comparing data of 6430 teeth or surfaces treated with SDF with 5466 teeth or surfaces treated with ART, the meta-analysis showed that SDF was significantly better at arresting caries as compared to ART (RR: 1.21 95% CI: 1.02, 1.44 95% I²: 96%) (Fig. 2). The caries arrest rate in the SDF group was 64.4% while in the ART group it was 55.2%. The funnel plot showed no significant asymmetry (Fig. 3). Egger’s test was not statistically significant (p = 0.10).

Fig. 2.

Meta-analysis of caries arrest rates between SDF and ART groups

Fig. 3.

Funnel plot for publication bias

Sensitivity analysis

Results of the sensitivity analysis are shown in Table 2. The results did not remain statistically significant after excluding multiple studies. Moreover, the inter-study heterogeneity did not decrease with the exclusion of any study.

Table 2.

Sensitivity analysis

Excluded study	Resultant risk ratio (95% confidence intervals)	I2
Santos 2012 [19]	1.15 [0.96, 1.38]	97
Zhi 2012 [26]	1.26 [1.03, 1.54]	97
Vollu 2019 [21]	1.27 [1.04, 1.54]	97
Abdellatif 2021 [22]	1.25 [0.97, 1.59]	97
El-Ghandour 2024 [23]	1.06 [0.95, 1.17]	88
Rodrigues 2025 [24]	1.29 [1.07, 1.55]	97
Ruff 2025 [20]	1.23 [0.94, 1.62]	97

Subgroup analysis

Subgroup analysis results are presented in Table 3. On segregating studies based on SDF application frequency (biannual vs. single), we found that the results were non-significant in both subgroups (Supplementary Fig. 1). The inter-study heterogeneity remained high. For the second subgroup analysis, we divided studies based on follow-up as 12 months or > 12 months. The results turned non-significant for both subgroups (Supplementary Fig. 2).

Table 3.

Subgroup analysis

Variable	Groups	Studies	Risk ratio (95% confidence intervals)	I2
Frequency of SDF application	Single Biannual	3 4	1.30 [0.65, 2.59] 1.12 [0.96, 1.31]	98 91
Follow-up	12 months > 12 months	4 3	1.46 [0.98, 2.20] 0.98 [0.83, 1.16]	98 88

SDF Silver Diamine Fluoride

Risk of bias analysis

Table 4; Fig. 4 display the risk of bias analysis for the included studies, based on reviewer judgement. Several studies received a “some concerns” rating for the randomization process due to inadequate reporting of sequence generation and allocation concealment, even though they stated that randomization was performed [19, 25, 26]. Conversely, later trials that clearly described their random sequence generation and allocation procedures were rated as low risk [20, 21, 23, 24]. One study was rated at high risk in this area because the randomization procedures were unclear, and baseline imbalances could not be ruled out [22]. Bias from deviations from intended interventions was low across all studies, as SDF and ART protocols were implemented as planned, with no evidence of differential co-interventions or treatment departures. Missing outcome data raised some concerns in all studies mainly due to attrition during follow-up. For outcome measurement, several trials had some concerns because caries arrest was assessed visually and tactilely, which can be subjective, and examiner blinding was insufficiently reported. One study [22] was rated high risk here because outcome assessors weren’t blinded, increasing detection bias risk. The selection of reported results was low risk across all studies, as outcomes matched study objectives and methods with no evidence of selective reporting. Overall, one trial was at high risk of bias, while the others had some concerns.

Table 4.

Risk of bias analysis

Study	Randomization process	Deviation from intended intervention	Missing outcome data	Measurement of outcomes	Selection of reported result	Overall risk of bias
Braga 2009 [25]	Some concerns	Low	Some concerns	Some concerns	Low	Some concerns
Santos 2012 [19]	Some concerns	Low	Some concerns	Some concerns	Low	Some concerns
Zhi 2012 [26]	Some concerns	Low	Some concerns	Some concerns	Low	Some concerns
Vollu 2019 [21]	Low	Low	Some concerns	Low	Low	Some concerns
Abdellatif 2021 [22]	High	Low	Some concerns	High	Low	High
El-Ghandour 2024 [23]	Low	Low	Some concerns	Some concerns	Low	Some concerns
Rodrigues 2025 [24]	Low	Low	Some concerns	Some concerns	Low	Some concerns
Ruff 2025 [20]	Low	Low	Some concerns	Some concerns	Low	Some concerns

Fig. 4.

Traffic light figure for risk of bias in included studies

GRADE assessment

Certainty of evidence based on GRADE is presented in Table 5. Given that all of the included studies were marked with “some concerns” or “high risk of bias” using the Cochrane risk of bias-2 tool, the certainty of evidence was downgraded to “very low”.

Table 5.

GRADE assessment of evidence for caries arrest

Number of studies	7
Downgrade quality of evidence
Risk of bias	Very serious*
Inconsistency	No
Indirectness	No
Imprecision	No
Publication bias	No
Upgrade quality of evidence
Large effect	No
Plausible confounding	No
Dose-response	No
Overall certainty of Evidence	Very low

*All studies had some concerns or high risk of bias. No study with low risk of bias

Discussion

This systematic review and meta-analysis of eight RCTs offers the most up-to-date evidence on the effectiveness of SDF versus ART in managing caries in children. A pooled analysis of data from 11,896 teeth or treated surfaces showed that SDF was significantly more effective at arresting caries in children. Overall, after a one-year follow-up, SDF was linked to a 21% higher rate of caries arrest compared to ART. However, the results lost significance during sensitivity analysis and became non-significant after excluding several studies. The summary estimates ranged from 1.06 to 1.29, suggesting a difference in caries arrest rates of 6% to 29%. Given the risk of bias in the included studies, the certainty of evidence was found to be “very low”.

At the outset the use of ‘caries arrest’ as an outcome should be justified. Although SDF and ART differ fundamentally in their approach, i.e. non-restorative versus restorative, both aim for biological control of the carious process. For SDF, success is defined as inactivation of the lesion through antimicrobial and remineralizing effects. In contrast, ART’s success is characterized by effective sealing of the lesion, preventing bacterial ingress, and maintaining lesion inactivity beneath the restoration. In both cases, the key clinical endpoint is the same: preventing lesion progression, symptoms, or the need for further intervention. Caries arrest, therefore, serves as a meaningful, patient-centred outcome that enables comparison of disease control across these treatments. However, variations in assessment criteria, such as restoration integrity for ART and surface hardness or discoloration for SDF, may influence outcome variability and should be considered when interpreting pooled data.

The present results are in in contrast with the previous review of Wakhloo et al. [14] which could include just four studies in the review and two studies in the meta-analysis, while comparing SDF vs. ART for childhood caries. The meta-analysis yielded non-significant results despite a tendency of better caries arrest rates with SDF as compared to ART (Odds ratio: 2.02 95% CI: 0.86, 4.71 I² = 62%). The Cochrane review [15] on the other hand has demonstrated that there was very low-quality evidence from four studies to suggest that SDF was better than ART in children. Zaffarano et al. [10] in their systematic review and meta-analysis demonstrated that the caries arrest rate of SDF was 51.6% but in the meta-analysis of just two studies there was no statistically significant difference in the caries arrest rate between SDF and ART. Thus, the present study is an important update in the literature as it includes a total of eight trials in the review and seven studies in the meta-analysis with a significantly large sample size which increases the statistical power of the analysis.

The effectiveness of SDF has been confirmed by placebo-controlled studies. A systematic review of studies comparing SDF with no treatment has demonstrated that SDF may help arrest caries in primary teeth [15]. Conversely, ART is the oldest MID technique, and meta-analysis studies have shown that single-surface ART restorations with high-viscosity GIC have high retention rates in both primary and permanent teeth [12, 13, 27]. Originally designed for use in impoverished communities, ART has exceeded expectations. Its use has now expanded to private practices in affluent industrialized nations [28]. However, ART has several limitations, including a potential reduction in long-term success rates, particularly in teeth with multiple carious lesions, and the risk of restorative failure with specific materials such as dental resin composites. Additionally, ART may not be suitable for all cavity locations or tooth types, and it may require longer treatment times and the use of local anesthetic, which can increase dental anxiety [29]. In comparison, SDF is a liquid solution applied directly to the tooth, allowing quick, straightforward application without drilling or anesthesia. This makes it especially valuable for children, individuals with special needs, and those suffering from dental phobia [15]. Another advantage of SDF over ART is its mode of action. It can arrest and prevent dental caries through a dual mechanism. The silver component of SDF acts as a potent antibacterial agent, disrupting bacterial cell membranes, denaturing proteins, and inhibiting DNA replication, leading to the death of cariogenic bacteria such as Streptococcus mutans, Actinomyces naeslundii, Lactobacillus acidophilus, and Lactobacillus rhamnosus. The fluoride ions in SDF are crucial for remineralization, as they promote the formation of fluorapatite, a more acid-resistant form of hydroxyapatite [30]. These mechanisms may account for the marginally superior effect of SDF over ART in caries arrest rates observed in our review.

The included studies exhibit some methodological and clinical differences. There was notable variation in SDF concentration (10–38%), the frequency of application, the types of dentition involved (primary, permanent, or mixed), and the use of additional preventive measures such as fluoride varnish. Moreover, other factors like children’s age, oral hygiene habits, compliance with fluoridated toothpastes, dietary factors and follow-up could also have contributed to the high heterogeneity. These factors could affect lesion activity, the extent of lesion arrest, and overall effectiveness. Nonetheless, subgroup analyses were limited because of the small number of studies in each category and inconsistent reporting, making detailed comparisons difficult. Outcomes were reported at the tooth or surface level and combined to capture the lesion-specific nature of caries progression and treatment response. It may also introduce heterogeneity due to variations in caries risk and exposure within individual patients. Given the high heterogeneity in the analysis and significant variations in the study protocols, the results of the review are to be interpreted with extreme caution.

The American Academy of Pediatric Dentistry recommends applying 38% SDF annually [8]; however, several included studies used 10% or 30% concentrations. Due to limited data, we were unable to perform subgroup analyses across these concentrations. However, we did categorize studies by application timing and follow-up, both of which yielded non-significant results, likely due to limited statistical power. A recent RCT has suggested that two applications of 38% SDF at one-month and four-month intervals are better at arresting caries than a single application at six-month intervals [31]. Similarly, Zhi et al. [26] showed that increasing the frequency of SDF application to once every 2 months increased caries arrest rates. Nevertheless, data are limited and more studies are needed to define the optimal frequency of SDF application for arresting caries in children.

Since only a limited amount of SDF is usually needed for topical application, no systemic adverse events have been reported with its use. However, gingival irritation, black staining of teeth, and adjacent soft tissues are some side effects that could be concerning for certain patients and parents [20]. This also limits its applicability to anterior teeth. The unaesthetic outcome can also be a barrier to the routine use of SDF in clinical practice, but this has been found to be true only for anterior, not posterior, teeth [24]. Most studies included in this review reported no major adverse events, indicating that SDF is safe for the management of dental caries in children.

A key limitation of this review is that it includes studies assessing both primary and permanent teeth without conducting separate quantitative analyses for each dentition type. While most trials focused solely on primary teeth, two studies [20, 25] involved mixed or permanent teeth. Biological and structural differences, such as enamel thickness, dentinal permeability, eruption status, and caries progression, may affect the effectiveness and durability of interventions like SDF and ART. Therefore, combining results from different dentitions may introduce clinical heterogeneity and limit the direct applicability of the findings to a specific tooth type. However, since both SDF and ART primarily work through local mechanisms at the lesion interface, and outcomes were consistently based on caries arrest rather than restoration longevity, the overall effect direction is unlikely to change significantly. Still, caution is advised when applying these results to permanent teeth, and future research should include dentition-specific analyses to improve clinical recommendations.

There are also other limitations to this review. As previously mentioned, the high heterogeneity of the meta-analysis is a significant concern that restricts the broader applicability of the results. The included publications used various protocols for application methods, including the frequency of administrations over time, which affected the solution’s effectiveness. Secondly, differing follow-up periods posed a concern, as failures occurring at later intervals might have been missed in studies with shorter follow-up. Thirdly, the studies were from limited regions and do not represent the global population. More research from underrepresented areas is necessary for the findings to be more broadly applicable. Fourthly, the risk of bias was not low across all studies; issues with randomization protocols and loss to follow-up were noted in several studies. Moreover, blinding was challenging between the SDF and ART groups, potentially introducing assessment bias. Fifthly, the manuscript focused only on caries arrest, and other important outcomes such as side-effects, acceptability, and retreatment could not be assessed due to lack of data from the included studies. Sixthly, although the focus was on pediatric patients, outcomes in this review were analyzed at the tooth or surface level, aligning with the primary studies’ unit of analysis. Dental caries is a localized disease, and treatments like SDF and ART act on individual lesions rather than the entire patient. Therefore, the most accurate way to assess caries arrest or recurrence is per treated tooth or surface. Finally, the strength of the association was modest, and non-significant results were observed during sensitivity and subgroup analyses.

Conclusions

Very low-quality evidence suggests that SDF is significantly but marginally more effective than ART in arresting dental caries in children. Lack of homogenization of protocols and variable study populations are important limitations of the meta-analysis, which also led to high inter-study heterogeneity. Further robust trials representing the global population are needed for generalization of the results.

Authors’ contributions

Conceptualization: WW; Formal analysis: WW, TM; Methodology: WW, TM; Writing – original draft: WW; Writing – review &amp; editing: WW, TM.

Funding

None.

Data availability

All data generated or analysed during this study are included in this published article and its supplementary information files.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.