Silver Diamine Fluoride: The Liquid That Stops Cavities

Silver diamine fluoride (SDF) is a clear liquid that a dental worker paints onto a cavity. In many trials the decay under it hardens and stops growing, with no drill and no needle. The price is visible: the treated decay turns dark brown to black. This page sets out what the liquid is, how it is put on, what the trials of children's baby teeth and older adults' roots found, how it compares with fluoride varnish and fillings, how parents and patients feel about the stain, and what is still not known. For the wider picture of how cavities form and the other ways they are treated, see the main Tooth Decay page.

Table of Contents

  1. What Silver Diamine Fluoride Is
  2. How It Is Put On a Tooth
  3. The Evidence in Children's Baby Teeth
  4. The Evidence on Older Adults' Root Surfaces
  5. Compared With Fluoride Varnish, Sealants and Fillings
  6. The Black Stain and How Families View It
  7. Other Side Effects Reported
  8. Who It Is Used For
  9. Its Status in the United States
  10. Cost and Access
  11. What Is Not Known
  12. Key Research Papers
  13. Connections
  14. Featured Videos

What Silver Diamine Fluoride Is

Silver diamine fluoride is a solution that contains three things: silver, fluoride and ammonia. A 2018 review in Advances in Dental Research describes it plainly as "a solution containing ionic silver, fluoride, and ammonia that arrests the progress of carious lesions and prevents the development of future caries."

The strength used most often is 38 percent. A 2008 review by University of Hong Kong researchers notes that a 38 percent solution carries 44,800 parts per million of fluoride ions, and that this strength is the one commonly used to stop decay in the baby teeth of young children.

Two ingredients, two jobs

The reviews describe a division of labour between the two active parts:

A 2022 review from Tokyo on decay of the tooth root puts the difference from other fluoride products this way: most fluoride products mainly reduce the formation of new cavities, while 38 percent silver diamine fluoride can stop an existing cavity, remineralize the decayed tissue and protect the tooth against new decay.

The same silver that kills bacteria causes the material's best-known drawback. When silver reacts with the decayed tooth it forms dark silver compounds, so the decay turns brown to black as it hardens. That stain is covered in its own section below.

Back to Table of Contents

How It Is Put On a Tooth

The appeal of silver diamine fluoride, in the words of the researchers who study it, is how little it takes. The 2018 review describes the whole procedure in three steps: "The lesion is isolated, and the solution is painted onto the clean caries lesion and dried."

Several things that make ordinary fillings hard for some patients are missing:

How long the liquid sits on the tooth may matter less than expected. In a 2018 Oregon study of 32 children aged 2 to 5, the length of time the liquid was applied was not linked to whether the decay stopped.

How often, and at what strength

The best-known trial on dosing was run by University of Hong Kong researchers (the Hong Kong dosing trial). They enrolled 888 children aged 3 to 4 who each had at least one active cavity in a baby tooth, and split them into four groups: 12 percent or 38 percent liquid, applied once or twice a year. After 30 months, 799 children were still in the study. The share of treated cavities that had stopped was:

Cavities treated with the 38 percent liquid were about twice as likely to stop as those treated with 12 percent (odds ratio 1.98). Among children treated only once a year, those with more plaque on their teeth were less likely to see their decay stop; the authors reported that in children with poor oral hygiene, moving from yearly to twice-yearly application raised the arrest rate.

Back to Table of Contents

The Evidence in Children's Baby Teeth

Most of the research on silver diamine fluoride has been done in young children with decay in their baby (primary) teeth. The results look strong in individual trials and weaker when strict reviewers grade them.

What the trials report

What the strictest review concluded

The 2024 Cochrane review is the most cautious summary. It gathered 29 randomized trials with 13,036 participants (12,020 children and 1,016 older adults). The reviewers rated every included study as having a high risk of bias, and some findings as imprecise because of small sample sizes.

For baby teeth, the review found that compared with placebo or no treatment, silver diamine fluoride "may help arrest caries" (an average of 0.86 more arrested tooth surfaces; 2 studies, 841 participants), but rated this evidence as low certainty. Whether it prevents new cavities in baby teeth was rated very uncertain. The reviewers' own words: "it may offer benefit over placebo or no treatment in caries arrest."

This gap between high arrest percentages in single trials and "low certainty" in the Cochrane grading is not a contradiction. The Cochrane method marks down trials that are small, unblinded (the black stain makes it hard to hide which tooth was treated) or analysed in ways that ignore several teeth in one mouth. The review asked for future studies to measure the impact of the stain and to account for that clustering.

The pediatric dentists' guideline

In 2017 a workgroup of the American Academy of Pediatric Dentistry published guidance on 38 percent silver diamine fluoride. The panel made a conditional recommendation for its use to arrest cavitated decay in baby teeth "as part of a comprehensive caries management program." Taking into account the low cost and the burden of decay, the panel members were "confident that the benefits of SDF application in the target populations outweigh its possible undesirable effects." The guideline itself labels this "a conditional recommendation based on low-quality evidence."

Back to Table of Contents

The Evidence on Older Adults' Root Surfaces

As people keep their natural teeth into old age, gums often pull back and expose the tooth root. Root surfaces have no enamel and decay easily. The 2022 Tokyo review calls root decay "a growing problem for the worldwide aging population." Silver diamine fluoride is studied here as a way to stop and prevent root decay in people who may not manage long dental appointments.

What the trials report

The 2025 scoping review of older adults

A 2025 review limited to adults aged 65 or older found only nine clinical studies. Two controlled trials showed the liquid stopped root decay, and two of three prevention trials reported a significant effect. A single-group trial reported an 86 percent root-decay arrest rate, while a study looking back at clinic records found that only 45 percent of treated lesions were still arrested after 24 months. One controlled trial reported 59 percent less plaque and 67 percent less gum inflammation with the liquid, and another found it relieved tooth sensitivity better than potassium nitrate. The authors concluded that "the evidence base remains limited" and called for rigorous trials on long-term results, safety and treatment schedules for this age group.

Back to Table of Contents

Compared With Fluoride Varnish, Sealants and Fillings

Fluoride varnish

Fluoride varnish is a sticky fluoride coating painted on the teeth, widely used to prevent decay (see the Tooth Decay page). Individual trials that compared it with silver diamine fluoride for stopping existing cavities mostly favoured the silver liquid:

The 2024 Cochrane review was more reserved. For preventing new cavities in baby teeth, it found silver diamine fluoride "may result in little or no difference" compared with fluoride varnish (low-certainty evidence, one study of 434 participants). For stopping existing decay, the evidence comparing the two in baby teeth was too uncertain for the reviewers to say either was better.

Sealants and hand-placed fillings in schools

The CariedAway trial in New York City tested silver diamine fluoride as a school program in primary schools where at least 80 percent of pupils received free or reduced-price lunches. Children received either silver diamine fluoride or glass ionomer sealants plus hand-placed atraumatic fillings, and every child in both groups also received fluoride varnish.

The Cochrane review, looking across all trials comparing the liquid with sealants or with hand-placed glass ionomer fillings, rated the evidence as very low certainty and could not say whether either was better.

Ordinary fillings

A traditional filling removes the decay and rebuilds the tooth, which also restores its shape and colour. Silver diamine fluoride does neither: it stops the decay in place and leaves the hole and the stain. A 2025 cost study from Singapore, built on a computer model of older adults with root decay over ten years, found that where a full dental clinic was available, fillings made of resin-modified glass ionomer cost less and gave more decay-controlled and extraction-free years than either silver diamine fluoride or sodium fluoride. In a community setting, for people who cannot reach a clinic because of mobility, memory or money problems, silver diamine fluoride came out as the most cost-effective option. The authors noted their model rested on limited clinical studies and on the Singapore health system.

The silver also affects later fillings. The 2018 review notes that silver particles in the dentine tubules "could create some bonding problems" for tooth-coloured composite fillings placed over a treated, darkened tooth, and the Tokyo review lists "impaired efficacy of dentin bonding" among the clinical disadvantages.

Back to Table of Contents

The Black Stain and How Families View It

The main drawback of silver diamine fluoride is the colour. The 2018 review states that the liquid "will produce a caries lesion darker (brown to black) than the original, which is the major criticism of the material."

How common the blackening is

In the Hong Kong trial of 888 preschool children, blackened decay was common in every group, and it rose with strength and frequency: 36.7 percent of children in the 12 percent once-a-year group, 49.5 percent with 12 percent twice a year, 65.6 percent with 38 percent once a year and 76.3 percent with 38 percent twice a year. In other words, the regimens that stopped the most decay also stained the most.

What parents say

Attempts to reduce the stain

A 2024 systematic review gathered 33 studies on reducing the discolouration, most of them laboratory studies. Three approaches were reported: covering the stain with a tooth-coloured filling; adding chemicals such as potassium iodide, hydrogen peroxide or glutathione; and replacing silver ions with silver nanoparticles, which in four studies did not discolour the decay. The reviewers concluded that more clinical trials are needed to confirm whether any of these work in real mouths. A 2022 Tokyo review proposed a two-visit approach for root decay that uses the darkening as a visible marker before a filling is placed.

Back to Table of Contents

Other Side Effects Reported

Beyond the stain, the reported side effects in trials have been minor and uncommon, though the strictest review grades the safety evidence as weak.

The 2024 Cochrane review rated the evidence on adverse effects as very uncertain and noted that the impact of staining "was poorly reported." The absence of serious harm in these trials is a finding about the people and follow-up periods studied, not proof that rare problems cannot occur.

Back to Table of Contents

Who It Is Used For

The research and guidance describe silver diamine fluoride as aimed at people for whom drilling and filling is hard to deliver or hard to tolerate:

A 2019 evidence update by two New York University researchers summarizes the role this way: it gives clinicians "an additional tool for caries management when esthetics are not a primary concern."

Back to Table of Contents

Its Status in the United States

Silver diamine fluoride had been used for decades in some Asian countries, including Japan and China, before it reached the United States. A 2016 review by University of Hong Kong researchers states that it "was recently cleared by the Food and Drug Administration in the United States as a fluoride to manage hypersensitive teeth."

The clearance was for tooth sensitivity, not for cavities. The 2018 review in Advances in Dental Research states that the material "was recently approved by the Food and Drug Administration for desensitizing cold-sensitive teeth and has been used off-label to treat carious lesions." Off-label means a dental professional uses a cleared product for a purpose that is not on its label; the review literature describes cavity treatment in exactly those terms.

Internationally, the CariedAway trial report notes that the World Health Organization lists glass ionomer cement and silver diamine fluoride as essential medicines for oral disease.

Back to Table of Contents

Cost and Access

Low cost is one of the reasons researchers give for studying silver diamine fluoride. The 2018 review states that "its low cost per application makes the material ideal for large populations," and the 2017 pediatric guideline panel weighed "the low cost of the treatment" in making its recommendation. The sources read for this page do not give a dollar price per tooth, and prices and insurance coverage vary by country and by dental practice.

The Singapore cost model is the most specific economic finding read for this page: for older adults with root decay, silver diamine fluoride was the most cost-effective option in a community setting without a dental clinic, but fillings were more cost-effective where a full clinic was available.

Access is the other half of the story. Because the liquid needs little equipment and no drill, the trials took it to schools, care homes and community programs, places where a dental chair is not available. The CariedAway authors concluded that their results "may support the use of silver diamine fluoride as an arresting and preventive agent in school-based oral health programs."

Back to Table of Contents

What Is Not Known

Decisions about treating a particular tooth belong with the person, their family and a dental professional who can see the tooth.

Back to Table of Contents

Key Research Papers

  1. Worthington HV, Lewis SR, Glenny AM, Huang SS, Innes NP, O'Malley L, Riley P, Walsh T, Wong MCM, Clarkson JE, Veitz-Keenan A. Topical silver diamine fluoride (SDF) for preventing and managing dental caries in children and adults. Cochrane Database Syst Rev. 2024;11(11):CD012718. PubMed PMID: 39508296
  2. Ruff RR, Barry Godín TJ, Niederman R. Noninferiority of Silver Diamine Fluoride vs Sealants for Reducing Dental Caries Prevalence and Incidence: A Randomized Clinical Trial. JAMA Pediatr. 2024;178(4):354-361. PubMed PMID: 38436947
  3. Ruff RR, Barry-Godín T, Niederman R. Effect of Silver Diamine Fluoride on Caries Arrest and Prevention: The CariedAway School-Based Randomized Clinical Trial. JAMA Netw Open. 2023;6(2):e2255458. PubMed PMID: 36757696
  4. Rodrigues GF, Vollú AL, Vargas TR, Kamp LMK, da Cunha Costa T, Cruz LR, Luiz RR, Barja-Fidalgo F, Fonseca-Gonçalves A. Efficacy of 30% silver diamine fluoride compared to atraumatic restorative treatment in arresting dentin caries lesions in preschoolers: a randomized clinical trial. Clin Oral Investig. 2024;29(1):3. PubMed PMID: 39641816
  5. Fung MHT, Duangthip D, Wong MCM, Lo ECM, Chu CH. Randomized Clinical Trial of 12% and 38% Silver Diamine Fluoride Treatment. J Dent Res. 2018;97(2):171-178. PubMed PMID: 28846469
  6. Duangthip D, Fung MHT, Wong MCM, Chu CH, Lo ECM. Adverse Effects of Silver Diamine Fluoride Treatment among Preschool Children. J Dent Res. 2018;97(4):395-401. PubMed PMID: 29237131
  7. Gao SS, Zhao IS, Hiraishi N, Duangthip D, Mei ML, Lo ECM, Chu CH. Clinical Trials of Silver Diamine Fluoride in Arresting Caries among Children: A Systematic Review. JDR Clin Trans Res. 2016;1(3):201-210. PubMed PMID: 30931743
  8. Crystal YO, Marghalani AA, Ureles SD, Wright JT, Sulyanto R, Divaris K, Fontana M, Graham L. Use of Silver Diamine Fluoride for Dental Caries Management in Children and Adolescents, Including Those with Special Health Care Needs. Pediatr Dent. 2017;39(5):135-145. PubMed PMID: 29070149
  9. Zhao X, He S, Tse S, Chu CH, Lo ECM, Jiang CM. Multifactorial analysis of the effectiveness of silver diamine fluoride application in arresting root caries. J Dent. 2026;170:106695. PubMed PMID: 41974365
  10. Bhat B, Singhal DK, Singla N, Nayak PP, Prabhu A, Anand L. Efficacy of Silver Diamine Fluoride vs. Sodium Fluoride in Arresting Root Caries Among the Olders in Care Homes: A Randomised Controlled Trial. Gerodontology. 2025. PubMed PMID: 41159551
  11. Chan AKY, Chu S, Yu OY, Chu CH. Clinical use of silver diamine fluoride in older adults: A scoping review. J Dent. 2025;162:106019. PubMed PMID: 40759309
  12. Hu S, Hong CHL, Gao X, Wee HL, Wang Y, Lai BWP, Ho SY, Allen PF, Tan SHX. Managing root caries with silver diamine fluoride, sodium fluoride and direct restorations: A cost-effectiveness analysis. J Dent. 2025;162:106093. PubMed PMID: 40914272
  13. Singhal R, Negi S, Namdev R, Kaushik H, Kakran A. Arrest of interproximal caries lesion in primary molars with 38% silver diamine fluoride solution and 5% sodium fluoride varnish: A randomized clinical trial. J Indian Soc Pedod Prev Dent. 2025;43(3):389-395. PubMed PMID: 41026564
  14. Sabino E Andrade R, Piovesan ÉTA, Queiroz IQD, Azevedo TDPL, Costa VPP, Bezerra ACB. Effectiveness of silver diamine fluoride and fluoride varnish in arresting caries lesions in permanent molars: A randomized controlled trial. J Dent. 2026;169:106647. PubMed PMID: 41871798
  15. Mendiratta M, B C M, Kumar A, Yadav V, Shyam R, Wig M. Effectiveness of silver diamine fluoride and glass ionomer cement combined with fluoride varnish in arresting dental caries among intellectually disabled individuals: A randomized controlled trial. Spec Care Dentist. 2021;41(5):544-552. PubMed PMID: 34033125
  16. Crystal YO, Janal MN, Hamilton DS, Niederman R. Parental perceptions and acceptance of silver diamine fluoride staining. J Am Dent Assoc. 2017;148(7):510-518.e4. PubMed PMID: 28457477
  17. Sabbagh H, Othman M, Khogeer L, Al-Harbi H, Al Harthi A, Abdulgader Yaseen Abdulgader A. Parental acceptance of silver Diamine fluoride application on primary dentition: a systematic review and meta-analysis. BMC Oral Health. 2020;20(1):227. PubMed PMID: 32819333
  18. Walia T, Shetty RM, Al-Sammarraie LM. Parents' and Children's Acceptance of Silver Diamine Fluoride Application on Primary Teeth in the United Arab Emirates. Oral Health Prev Dent. 2022;20:533-540. PubMed PMID: 36511761
  19. Xu GY, Yin IX, Zhao IS, Lung CY, Lo EC, Chu CH. Minimizing tooth discoloration caused by topical silver diamine fluoride application: A systematic review. J Dent. 2024;150:105353. PubMed PMID: 39284509
  20. Burgess JO, Vaghela PM. Silver Diamine Fluoride: A Successful Anticarious Solution with Limits. Adv Dent Res. 2018;29(1):131-134. PubMed PMID: 29355424
  21. Mei ML, Lo EC, Chu CH. Clinical Use of Silver Diamine Fluoride in Dental Treatment. Compend Contin Educ Dent. 2016;37(2):93-8; quiz100. PubMed PMID: 26905088
  22. Chu CH, Lo EC. Promoting caries arrest in children with silver diamine fluoride: a review. Oral Health Prev Dent. 2008;6(4):315-21. PubMed PMID: 19178097
  23. Clemens J, Gold J, Chaffin J. Effect and acceptance of silver diamine fluoride treatment on dental caries in primary teeth. J Public Health Dent. 2018;78(1):63-68. PubMed PMID: 28749529
  24. Hiraishi N, Sayed M, Takahashi M, Nikaido T, Tagami J. Clinical and primary evidence of silver diamine fluoride on root caries management. Jpn Dent Sci Rev. 2022;58:1-8. PubMed PMID: 34950254
  25. Crystal YO, Niederman R. Evidence-Based Dentistry Update on Silver Diamine Fluoride. Dent Clin North Am. 2019;63(1):45-68. PubMed PMID: 30447792
  26. Wright JT, White A. Silver Diamine Fluoride: Changing the Caries Management Paradigm and Potential Societal Impact. N C Med J. 2017;78(6):394-397. PubMed PMID: 29203603
  27. Buldur B, Taskaya B. Clinical effectiveness and parental acceptance of silver diamine fluoride in preschool children: a non-randomized trial. J Clin Pediatr Dent. 2024;48(6):78-88. PubMed PMID: 39543884

PubMed Topic Searches

  1. PubMed: silver diamine fluoride and caries arrest in children
  2. PubMed: silver diamine fluoride and root caries in older adults
  3. PubMed: silver diamine fluoride versus fluoride varnish
  4. PubMed: silver diamine fluoride staining and parental acceptance

Back to Table of Contents

Connections

Back to Table of Contents