Evidence-Based Dentistry Update on Silver Diamine Fluoride

This article reviews current evidence on the effectiveness of silver diamine fluoride (SDF) as a caries arresting and preventive agent. It provides clinical recommendations around SDF’s appropriate use as part of a comprehensive caries management program. Systematic reviews confirm that SDF is effective for caries arrest on cavitated lesions in primary teeth and root caries in the elderly. It may also prevent new lesions. Application is easy, noninvasive, affordable, and safe. Although it stains the lesions dark as it arrests them, it provides clinicians with an additional tool for caries management when esthetics are not a primary concern.

Key points

  • Silver diamine fluoride incorporates the antibacterial effects of silver and the remineralizing actions of a high-concentration fluoride. It effectively arrests the disease process on most lesions treated.

  • Systematic reviews of clinical trials confirm the effectiveness of silver diamine fluoride as a caries-arresting agent for primary teeth and root caries and its ease of use, low cost, and relative safety.

  • No caries removal is necessary to arrest the caries process, so the use of silver diamine fluoride is appropriate when other forms of caries control are not available or feasible.

  • A sign of arrest is the dark staining of the lesions and affected tooth structures. That could be a deterrent for patients who have esthetic concerns. A thorough informed consent is recommended to ensure high patient satisfaction.

  • Silver diamine fluoride use for caries control is recommended as part of a comprehensive caries management program, where individual needs and risks are considered.

Introduction

The global burden of oral disease and the negative social and economic effect associated with it, are a growing problem worldwide.

The widespread use of water fluoridation and fluoride-containing oral products produced significant decreases in the prevalence and severity of dental caries over the last 70 years. However, the benefits of these prevention interventions have not materialized in all segments of society in most countries. Free sugars and processed carbohydrates as a component of diet have increased in many countries, both developed and developing alike. As Thompson and colleagues have shown, lower income groups are particularly vulnerable to high dietary sugar intake. The result has been a disparity in caries experience across socioeconomic groups. In the United States and other high-income countries, untreated dental decay in children is strongly patterned by income and ethnicity, mainly owing to cost and limited availability and/or access to services. In lower income groups, much of the caries goes untreated, resulting in severe disease levels that leads to pain, expense, and a decreased quality of life for the affected children and their families.

Even when dental services are accessible, traditional restorative treatment can be difficult to deliver to young children with severe disease and those with special management considerations. To address this difficulty, advanced forms of behavior management like sedation and/or general anesthesia are often used, which increase the cost and the risk for the patient and the dentist. Elderly patients often face similar challenges, because increasing rates of untreated decay can severely affect their quality of life, and the difficulties of receiving dental care are accentuated by limitations with mobility and other comorbidities.

When it comes to prevention, epidemiologic studies indicate that when the bacterial challenge is high or the salivary components are lacking, natural remineralization or that aided by fluoride products is insufficient to prevent or arrest the caries process. Thus, there is an urgent need to find ways to beneficially modify the biofilm and to enhance the remineralization process to decrease caries experience and attain improved outcomes of oral health. This situation calls for a paradigm change in caries prevention and management. Specifically, we need more effective, affordable, accessible, and safe treatments that are easy to implement in different settings, and are available to the most vulnerable populations.

Silver diamine fluoride (SDF), a clear liquid that combines the antibacterial effects of silver and the remineralizing effects of fluoride, is a promising therapeutic agent for managing caries lesions in young children and those with special care needs that has only recently become available in the United States. Multiple in vitro studies document its effectiveness in reducing specific cariogenic bacteria and its remineralizing potential on enamel and dentin. Its in vivo mechanism(s) of action are a subject of ongoing research. What is currently understood is that the fluoride component strengthens the tooth structure under attack by the acid byproducts of bacterial metabolism, decreasing its solubility, but SDF may also interfere with the biofilm, killing bacteria that cause the local environmental imbalance that demineralizes dental tissues. Thus, SDF becomes one of the tools available to address caries by modifying the bacterial actions on the tissue while enhancing remineralization.

Numerous systematic reviews substantiate SDF’s efficacy for caries arrest in primary teeth, and arrest and prevention of new root caries lesions. It meets the US Institute of Medicine’s 6 quality aims of being :

  • 1.

    Safe—clinical trials that have used it in more than 3800 individuals have reported no serious adverse events ;

  • 2.

    Effective—arrests approximately 80% of treated lesions ;

  • 3.

    Efficient—can be applied by health professionals in different health and community settings with minimal preparation in less than 1 minute;

  • 4.

    Timely—its ease of application can allow its use as an intervention agent as soon as the problem is diagnosed;

  • 5.

    Patient centered—is minimally invasive and painless, meeting the immediate needs of a child or adult in 1 treatment session; and

  • 6.

    Equitable—its application is equally effective and affordable; with the medicament costing less than $1 per application, it is a viable treatment for lower income groups.

The only apparent drawback is that as the caries lesions become arrested, the precipitation of silver byproducts in the dental tissues stain the lesions black, which can be a deterrent for its use in visible areas ( Figs. 1–4 ).

Fig. 1
( A ) Enamel and dentin caries lesions in primary anterior teeth. ( B ) Same lesions showing staining after SDF treatment.

Fig. 2
( A ) Caries lesions on enamel and dentin on young primary teeth. ( B ) Same lesions showing staining after SDF treatment.

Fig. 3
Stained arrested caries lesions on primary anterior teeth.

Fig. 4
Staining on non-cavitated and partially-cavitated enamel lesions.

Systematic syntheses of clinical trials’ findings constitute the highest level of evidence and are essential to inform evidence-based guidelines and set the standard of care in all settings of dental practice. This article presents and discusses the findings of systematic reviews and metaanalysis of SDF as a treatment for caries arrest and prevention.

Background

Silver compounds, especially silver nitrate, have been used in medicine to control infections for more than a century. In dentistry, reports of use of silver nitrate are well-documented for caries inhibition and, before the twentieth century, silver nitrate was firmly entrenched in the profession as a remedy for “hypersensitivity of dentin, erosion and pyorrhea, and as a sterilizing agent and caries inhibitor in deciduous as well as in permanent teeth.” Howe’s solution (ammoniacal silver nitrate, 1917), was reported to disinfect caries lesions and continued to be used for nearly one-half of a century as a sterilizing and disclosing agent for bacterial invasion of dentin to avoid direct pulp exposures, to detect incipient lesions, and to disclose leftover carious dentin.

The relationship of fluorides and caries prevention had been well-established through epidemiologic observations, chemical studies, animal experiments, and clinical trials beginning in the early decades of the twentieth century. It is now well-known that, when fluoride combines with enamel or dentin, it greatly reduces their solubility in acid, promotes remineralization, and results in a reduction of caries.

The use of ammoniacal silver fluoride for the arrest of dental caries was pioneered by Drs Nishino and Yamaga in Japan, who developed it to combine the actions of F and Ag + and led to the approval of the first SDF product, Saforide (Bee Brand Medico Dental Co, Ltd, Osaka, Japan) in 1970. Each milliliter of product contains 380 mg (38 w/v%) of Ag(NH 3 ) 2 F. They described its effects for prevention and arrest of dental caries in children, prevention of secondary caries after restorations, and desensitization of hypersensitive dentin. They reported that it penetrated 20 μm into sound enamel. In dentin, reported penetration of F was up to 50 to 100 μm and Ag + went deeper than that, getting close to the pulp chamber. They warned that because the agent stains the decalcified soft dentin black, its application should be confined to posterior teeth and gave specific instructions for its application.

Other similar products then became commercially available in other regions, like Silver Fluoride 40% in Australia (SCreighton Pharmaceuticals, Sydney), Argentina (SDF 38% several brands), and Brazil (several SDF concentrations and brands).

Since 2002, the search for innovative approaches to address the caries pandemic resulted in the publication of many clinical trials of SDF efficacy (through comparison with no treatment), and its comparative effectiveness with other chemopreventive agents (eg, fluoride varnish [FV]), as well as other treatment interventions (eg, atraumatic restorative treatment [ART]). The results of these studies established the effectiveness of SDF as a caries arresting agent. In 2014, the US Food and Drug Administration approved SDF as a device for dentin desensitization in adults and, in 2015, the first commercial product became available in the United States: Advantage Arrest. Advantage Arrest (Elevate Oral Care, LLC, West Palm Beach, FL) is a 38% SDF solution ( Box 1 ).

Box 1
Manufacturer production description of silver-diamine fluoride 38%
Data from Refs.

Silver-Diamine Fluoride 38% Professional tooth desensitizer
Desensitizing ingredient Aqueous silver diamine fluoride, 38.3%–43.2% w/v
Presentation Light-sensitive liquid with ammonia odor and blue coloring
8 mL dropper-vials contain: approximately 250 drops; enough to treat 125 sites; a site is defined as up to 5 teeth; the unit-dose ampule contains 0.1 mL per ampule
Specific gravity 1.25
Composition 24%–27% silver
7.5%–11.0% ammonia
5%–6% fluoride (approximately 44,800 ppm)
<1% blue coloring
≤62.5% deionized water

Manufacturer’s instructions are limited to its approved use as a dentin desensitizer in adults. However, results from clinical trials conducted in many different countries on more than 3900 children have led investigators to develop recommendations for its use as a caries arrest medicament in children.

In 2017, the American Academy of Pediatric Dentistry published a Guideline for the “Use of Silver Diamine Fluoride for Dental Caries Management in Children and Adolescents, Including Those with Special Health Care Needs.” This document encouraged the off-label adoption of this therapy for caries arrest, much as FV is used for caries prevention. In November 2016, the US Food and Drug Administration granted SDF a breakthrough therapy status, which facilitates clinical trials of SDF for caries arrest to be carried out in the United States. Studies are currently underway that may result in the change of its labeling in the near future.

Since 2009, systematic reviews report on SDF’s ability to arrest or prevent caries lesions. For this article, we reviewed systematic reviews reported in English and published or accepted for publication through March 2018. We identified 6 systematic reviews that met most of the PRISMA guidelines. Their details can be found in Table 1 . The outcomes reported in these reviews include efficacy (ability to arrest or prevent caries lesions) and comparative effectiveness (eg, equivalence or superiority when compared with other modalities such as ART and FV). Included reviews report on the primary and permanent dentitions of children and the permanent teeth on elderly populations. We consider each endpoint separately herein.

Table 1
Systematic reviews/metaanalysis on silver diamine fluoride trials
Author, Year Outcome Measures Studies Included and Max Follow-up Time Analyzed a Dentitions Included/Frequency of SDF Application b Results
Rosenblatt et al, 2009 Caries arrest and caries prevention Systematic review only SDF prevented fraction: caries arrest = 96.1%; caries prevention = 70.3%
Chu, 2002 30 mo Primary max ant/q 12 mo
Llodra, 2005 36 mo Primary post teeth and First permanent molars/q 6 mo
Horst et al, 2016 Caries arrest and/or prevention Systematic review only Descriptive for each of the studies
Chu, 2002 30 mo Primary max ant/q 12 mo
Llodra, 2005 36 mo Primary post teeth and First permanent molars/q 6 mo
Zhi, 2012 24 mo Primary ant and post/q 6 and q 12 mo
Yee, 2009 24 mo Primary ant and post/1 app only
Liu, 2012 24 mo Permanent first molars/q 12 mo
Monse, 2012 18 mo Permanent first molars/1 app only
Dos Santos, 2014 12 mo Primary ant and post/1 app only
Zhang, 2013 24 mo Root caries on elders/q 12 and q 24 mo
Tan, 2010 36 mo Root caries on elders/q 12 mo
Gao et al, 2016 Caries arrest in children Metaanalysis included only SDF 38% at different time periods Caries arrest rate of SDF 38% was
86% at 6 mo
81% at 12 mo
78% at 18 mo
71% at 30 mo or >
Overall arrest was 81% (95% CI, 68%–89%; P <.001)
Chu, 2002 30 mo Primary max ant/q 12 mo
Llodra, 2005 36 mo Primary post teeth and First permanent molars/q 6 mo
Zhi, 2012 24 mo Primary ant and post/q 6 and q 12 mo
Yee, 2009 24 mo Primary ant and post/1 app only
Wang, 1964 Chinese 18 mo Primary ant and post/q 3 and q 4 mo
Yang, 2002 Chinese 6 mo Primary teeth/1 app only
Ye, 1994 Chinese 12 mo Primary teeth/1 app only
Fukumoto, 1997 Japanese 48 mo Primary teeth/1app only
Chibinski et al, 2017 Control of caries progression in children after 12 mo follow-up Metaanalysis included only studies with “low risk” of bias
Evaluated at 12 mo results only (regardless of follow-up time)
Caries arrest was 89% higher than using active materials/placebo at 12 mo
SDF vs control materials
Duangthip, 2016 12 mo Primary ant and post/1 app/year or 3 app weekly at baseline
Zhi, 2012 24 mo Primary ant and post/q 6 and q 12 mo
NSP or SDF vs placebo
Dos Santos, 2014 Primary ant and post/1 app only
NSP 12 mo
Seberol and Okte, 2013 Primary max ants only/1 app only
SDF (unpublished) 12 mo
Oliveira et al, 2018 Prevention of new caries lesions in primary teeth Metaanalysis included comparable studies evaluated at ≥24 mo SDF applications reduce development of dentin lesions in treated and untreated primary teeth
PF: 77.5%; 95% CI, 67.8%–87.2%
SDF vs placebo
Chu, 2002 30 mo Primary max ant/q 12 mo
Llodra, 2005 36 mo Primary post teeth and First permanent molars/q 6 mo
SDF vs GIC
Dos Santos, 2012 12 mo Primary ant and post/1 app only
Hendre et al, 2017 Caries arrest and prevention in older adults Systematic review only
  • Prevention:

    • PF of SDF vs placebo = 71% in 36-mo study

    • 21% in a 24-mo study

  • Arrest:

    • PF of SDF vs placebo = 725% greater in 24-mo study

    • 100% greater in 30 mo study

Tan, 2010
n = 203
36 mo Root caries on elders/q 12 mo
Zhang, 2013
n = 227
24 mo Root caries on elders/q 12 and q 24 mo
Li, 2016
n = 67
30 mo Root caries on elders/q 12 and q 24 mo

Abbreviations: ant, anterior; app, reapplication; CI, confidence interval; NSP, nano-silver particles; PF, preventive fraction; post, posterior; SDF, silver-diamine fluoride.

a Number of subjects in published studies for SDF in children are included in Table 2 n = listed in this table corresponds with the number of subjects in the study quoted not included in Table 2 .

b q × mos refers to frequency of reapplication in months.

Current evidence on the efficacy of silver diamine fluoride for caries arrest and prevention

In this section, we evaluate the results for SDF’s efficacy for caries arrest as reported by the systematic reviews and metaanalysis included in Table 1 . These systematic reviews used different perspectives to evaluate 17 prospective, parallel design, randomized, controlled clinical trials with a clearly defined outcome. As a result, and apparent from Table 1 , many of the systematic reviews included refer to the same body of clinical trials, just updating results as additional studies became available. Details of each of the included clinical trials conducted on children and published in English are included in Table 2 .

Table 2
Description and clinical details of randomized control trials on children
Modified from Crystal YO, Niederman R. Silver diamine fluoride treatment considerations in children’s caries management. Pediatr Dent 2016;38(7):467–8; with permission.
Chu et al, 2002 Yee et al, 2009 Zhi et al, 2012 Dos Santos et al, 2012 Duangthip et al, 2018 Fung et al, 2018 Llodra et al, 2005 Braga et al, 2009 Liu et al, 2012 Monse et al, 2012
Location China Nepal China Brazil Hong Kong China Cuba Brazil China Philippines
Dentition studied Primary anterior only Primary Primary anterior and posterior Primary Primary anterior and posterior Primary anterior and posterior Primary cuspids, molars and permanent first molars Permanent first molars Permanent first molars Permanent first molars
Caries effect studied Arrest Arrest Arrest Arrest Arrest Arrest Arrest and prevention Arrest Prevention Prevention
Groups compared
  • 1.

    SDF (38%) 1×/y with caries removal

  • 2.

    SDF (38%) 1×/y without caries removal

  • 3.

    FV 5% 4× y with caries removal

  • 4.

    FV 5% 4× y without caries removal

  • 5.

    Water control

  • 1.

    SDF (38%) 1× followed by tannic acid as reducing agent

  • 2.

    SDF (38%) 1× alone

  • 3.

    SDF (12%) 1× alone

  • 4.

    No treatment

  • 1.

    SDF (38%) 1×/y

  • 2.

    SDF (38%) 2×/y

  • 3.

    GI (Fuji VII) w/conditioner 1×/y

  • 1.

    SDF(30%)

  • 2.

    ITR (Fuji IX) w/conditioner

  • 1×.

  • 1.

    SDF (30%) 1×/y

  • 2.

    SDF (30%) 1×/week for 3 wk at baseline

  • 3.

    FV (5%) 1×/wk for 3 wk at baseline

  • 1.

    SDF (38%) 2×/y

  • 2.

    SDF (38%) 1×/y

  • 3.

    SDF (12%) 2×/y

  • 4.

    SDF (12%) 1×/y

  • 1.

    SDF (38%) 2×/y

  • 2.

    No treatment

  • 1.

    SDF (10%) 3× at 1-wk interval

  • 2.

    GI (Fuji III) sealant 1×

  • 3.

    Cross tooth-brushing

  • Noncavitated caries lesions

  • On each child 1 molar was assigned to each group

  • 1.

    SDF (38%) 1×/y

  • 2.

    Resin sealant

  • 3.

    5% NaF varnish 2× y

  • 4.

    Yearly placebo

  • Deep fissures or noncavitated early lesions

  • Each child got same treatment in all molars

  • 1.

    SDF (38%) 1× on sound and cavitated molars

  • 2.

    ART (high-viscosity Ketac molar) on sound and cavitated molars

  • 3.

    NT

  • Some schools had toothbrushing programs and some did not

Main findings
  • 1.

    SDF was more effective than FV or control (65% arrested lesions for SDF groups vs 41% for FV groups vs 34% for control)

  • 2.

    Caries removal had no effect

  • 3.

    Control group developed more new caries than treatment groups

  • 1.

    SDF was more effective than controls (31% arrested lesions for SDF groups vs 22% for SDF 12% vs 15% for control)

  • 2.

    Tannic acid had no effect

  • 3.

    Arrest benefit decreases over time

  • 1.

    SDF and GI are equally effective (91% arrested lesions for SDF 2×/y vs 79% SDF 1×/y, vs 82% GI 1×/y)

  • 2.

    Increasing frequency of SDF (2×/y) increases caries arrest

  • 3.

    Anterior teeth and buccal/lingual surfaces are more likely to become arrested

  • 1.

    SDF was more effective than ITR (67% arrested lesions in SDF group vs 39% in control)

  • 1.

    SDF 1×/y was more effective than SDF or FV 3 weekly applications at baseline (arrest of cavitated lesions: 48% SDF 1x/y vs 33% in group 2% and 34% with FV; for arrest of moderate lesions the 3 protocols were equally effective: 45% SDF 1×/y vs 44% in group 2% and 51% with FV) c

  • 1.

    SDF 38% 2×/y was more effective than SDF 38% 1×/y, SDF 12% 2×/y or 1×/y (77% arrested lesions vs 67%, 59% and 55%, respectively)

  • 1.

    SDF 2×/y was more effective for caries arrest than controls (85% arrested lesions with SDF vs 62% in control)

  • 2.

    SDF was effective for caries reduction in both primary and permanent teeth (0.29 surfaces with new caries in SDF group vs 1.43 in control in primary teeth and 0.37 vs 1.06 in permanent molars)

  • 1.

    SDF was more effective than toothbrushing or GI at 3 and 6 mo

  • 2.

    All equally effective in controlling initial (noncavitated) occlusal caries at 30 mo

  • 1.

    The 3 active treatments are effective in caries prevention (progression of caries into dentin was 2.2% for SDF, 1.6% for sealant, 2.4% for FV vs 4.6% for control)

  • 2.

    Control group developed more dentin caries than treatment groups

  • 1.

    ART sealants were more effective than a single application of SDF (caries increment in the brushing group was: 0.08 for NT; 0.09 for SDF; 0.01 for sealants. In nonbrushing group: 0.17 for NT; 0.12 for SDF; 0.06 for sealants)

    • 2.

      Caries increment was lower in tooth-brushing group

Additional findings
  • 1.

    Arrested lesions looked black without changing parental satisfaction (93% of parents did not mention a difference)

  • 1.

    Single SDF application prevented one-half of arrested surfaces at 6 mo from reverting to active lesions again over 24 mo

  • 2.

    No complaints from parents or children to SDF

  • 1.

    GI provides a more esthetic outcome.

  • 2.

    Only 3.5% retention of GI after 24 mo still provides caries arrest

  • 3.

    45% of parents in all groups were satisfied with appearance

  • 1.

    43% of GIC fillings were lost at 6 mo and dentin was soft.

    • 2.

      Higher rate of failure when GIC involved multiple surfaces.

  • 1.

    Lesions in anterior teeth, buccal/lingual surfaces and lesions with no plaque had a higher chance to become arrested

  • 1.

    Lesion site was significant, with lower anteriors having the highest rates of arrest followed by upper anteriors, lower posterior, and upper posterior

  • 2.

    Lesions with visible plaque and large lesions had lower chance of becoming arrested

  • 1.

    SDF showed more efficacy to arrest decay in deciduous teeth than permanent teeth

  • 1.

    Retention rates for GI sealants were 32% at 6 mo and 9% at 30 mo

  • 2.

    GI sealants were more time consuming that SDF application

  • 1.

    Teeth with early caries at baseline were more likely to develop dentin caries after 24 mo

  • 2.

    46% sealant retention

  • 1.

    Retention rate for sealants was 58% after 18 mo

SDF
Clinical Application
Protocol
  • a Two treated groups had caries removal and 2 did not

  • a Does not specify SDF amount used or time of exposure

a No caries removal
a One drop of SDF applied for 2 min to carious surfaces and dried with cotton pellet
a No food or drink for 1 h after
a Minor excavation
a Does not specify SDF amount used or time of exposure
a No food or drink for 30 min after
a No caries removal
a Does not specify SDF amount used
a Cotton roll isolation, petroleum jelly on gingiva, SDF applied for 3 min and rinse and spit
a No food or drink for 1 h
a No caries removal
a Does not specify SDF amount used or kind of isolation
a SDF rubbed for 10 s

  • No food or drink for 30 min

a Does not specify SDF amount used, time of exposure, or kind of isolation a Minor decay excavation on permanent molars only
a Does not specify SDF amount used
a Cotton roll isolation, SDF applied for 3 min and wash for 30 s
a No caries removal
a Does not specify SDF amount used
a Cotton roll isolation and petroleum jelly on gingiva, SDF applied for 3 min, and wash for 30 s
a No food or drink for 1 h
a Does not specify SDF amount used, time of exposure, or whether it was rinsed or not
a Cotton roll isolation
a No food or drink for 30 min
a Does not specify SDF amount used, SDF rubbed for 1 min followed by tannic acid, dried with cotton pellet, and covered with petroleum jelly
a Cotton roll isolation
Adverse effects None None None None None None 0.1% Gingival irritation None None None
Duration of study (mo) 30 24 24 12 30 30 36 30 24 18
Baseline caries 3.92 dmfs (active anterior lesions) 6.8 dmfs (active lesions) 5.1 dmft (3 random teeth/child) 3.8 dmft 4.4 dmft
6.7 dmfs
3.84 dmft
5.15 dmfs
3.2 dmft Noncavitated molar occlusal No cavitated lesions At least 1 sound permanent molar
Background F exposure Low F exposure reported use of F toothpaste Low F exposure
Provided F toothpaste
Low F exposure low access to F toothpaste Low F exposure access to F toothpaste F water
F toothpaste
Low F exposure
F toothpaste
Low F exposure
+ 0.2% NaF rinse in school every other week
Low F exposure
Provided F toothpaste
Low F exposure
Provided F toothpaste
Low F exposure
Provided F toothpaste
No. of subjects at baseline 375 976 212 91 371 b 888 425 22 children, 66 molars 501 1016
No. of subjects at endpoint 308 634 181 ? 309 b 799 373 ? 485 704
Examinations after baseline ×6 mo 1, 12, and 24 mo ×6 mo ×6 mo ×6 mo ×6 mo ×6 mo 3, 6, 12, 18 and 30 mo plus radiographs at 6, 12 and 30 mo ×6 mo 18 mo
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Aug 9, 2020 | Posted by in General Dentistry | Comments Off on Evidence-Based Dentistry Update on Silver Diamine Fluoride

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