Silver Diamine Fluoride: From G.V. Black to Modern Caries Management
In 1908, G.V. Black wrote something that sounds surprisingly modern. In his chapter on treating children, the man remembered as the father of operative dentistry advised dentists in selected cases to “leave the decayed material in the dentin where it is” rather than painfully excavating it. He then treated the remaining carious dentin with silver nitrate, watched for the characteristic blackening, followed the child over time, and repeated treatment when necessary. More than a century later, dentistry is again using silver to arrest caries without immediately removing tooth structure, this time with a far better understood material called silver diamine fluoride.
The connection should not be exaggerated. Black did not invent SDF, and silver nitrate was being used against caries as far back as the 1840s. Nor did dentistry somehow abandon a perfect treatment because dentists preferred drilling. Local anesthesia, rotary instrumentation, fluoride, adhesive materials, stainless steel crowns, pulp therapy, and restorative science transformed what dentists could accomplish. Still, Black’s writing is a reminder that the idea of chemically controlling caries has deep roots. He understood that lesion control, patient comfort, follow-up, and restoration did not always have to happen at the same moment.
Percy R. Howe carried that concept forward at the Forsyth Dental Infirmary for Children in Boston. Around 1917, Howe developed an ammoniacal silver nitrate preparation that became known as Howe’s solution. Ammonia improved the behavior of the silver preparation, and the material was used to arrest caries in children. The next major step came decades later at Osaka University in Japan. Professor Reiichi Yamaga and Ichiro Yokomizo developed a stable silver ammonia fluoride formulation and claimed Japanese patent priority in 1967. Professor Mizuho Nishino then performed landmark laboratory, animal, and clinical research demonstrating that ammoniacal silver fluoride could substantially inhibit caries progression in primary teeth. Her 1969 doctoral work remains one of the foundational scientific documents in the history of SDF.
That history matters because Nishino is sometimes credited as the sole inventor of silver diamine fluoride. The record is more interesting. Modern SDF emerged from a research program involving Yamaga, Yokomizo, Nishino, and other Osaka University investigators. Yamaga and Yokomizo patented the stable formulation. Nishino helped establish what it could actually do clinically. By about 1970, Saforide had entered clinical use in Japan, and in 1972 Yamaga, Nishino, Yoshida, and Yokomizo published “Diammine Silver Fluoride and Its Clinical Application,” helping introduce the material to a broader dental audience.
Even the name carries a small chemistry lesson. Dentistry commonly calls the material silver diamine fluoride, or SDF. Chemically, silver diammine fluoride, with two m’s in “diammine,” is more precise because the silver ion is coordinated with two ammonia molecules. The FDA uses silver diammine fluoride as its preferred substance name while recognizing silver diamine fluoride as a synonym. In clinical conversation, SDF remains the practical term.
The typical material used today is 38% SDF. Silver contributes broad antimicrobial activity, fluoride promotes remineralization and acid resistance, and ammonia stabilizes the silver complex. SDF also appears to inhibit enzymes involved in degradation of dentinal collagen. Describing it to patients as “silver fights the bacteria and fluoride strengthens the tooth” is understandable chairside shorthand, but the biology is more complicated. SDF does not sterilize a lesion. It changes the microbial environment, limits further dentin breakdown, promotes mineral deposition, and helps convert an active lesion into a harder, inactive one.
That distinction becomes clearer when caries is treated as a disease rather than simply a hole. Contemporary cariology describes dental caries as a biofilm-mediated, sugar-driven, multifactorial, dynamic process involving repeated cycles of mineral loss and repair. A cavity is one possible structural consequence of that disease. Frequent fermentable carbohydrate exposure can shift the oral biofilm toward an acidic ecology that favors acid-producing and acid-tolerant organisms. Fluoride, saliva, diet, plaque control, and patient behavior can shift the balance back in the other direction.
This is where dentists can easily oversell SDF. Painting one lesion does not cure the patient’s caries disease. A child who drinks sugar throughout the day, an older adult with severe xerostomia, or a patient with poor plaque control remains at risk for new disease even if one lesion has been successfully arrested. SDF is best understood as a lesion-management tool within a larger caries-management strategy.
The clinical evidence is strongest in cavitated lesions in primary teeth and in root caries. The American Dental Association’s 2018 nonrestorative caries guideline recommends prioritizing twice-yearly 38% SDF for advanced cavitated lesions in primary teeth. The ADA also allows consideration of SDF for advanced cavitated lesions in permanent teeth, although the evidence there was less certain. The American Academy of Pediatric Dentistry supports SDF for arresting cavitated lesions in primary teeth as part of comprehensive caries management.
The World Health Organization has now pushed the concept further into mainstream global oral health. Its 2026 guideline strongly recommends 38% SDF applied twice yearly for cavitated carious lesions without pulpal involvement in primary teeth and for cavitated root-surface lesions in permanent teeth. WHO also discusses SDF for prevention, but that recommendation is conditional and based on weaker evidence. That distinction matters. SDF has strong support for specific disease states. It should not be interpreted as a universal replacement for restorative treatment.
Case selection remains the dentist’s job. A lesion with signs of pulpal disease, significant structural failure, inability to maintain cleansability, food impaction, occlusal problems, or unacceptable esthetics may still need restorative or surgical treatment. Arresting a lesion also does not reconstruct missing anatomy. A molar can become hard and inactive yet still require glass ionomer, composite, a crown, pulp therapy, or extraction for reasons that have nothing to do with whether the caries itself has stopped progressing.
The black staining is the tradeoff every dentist must discuss clearly. SDF permanently darkens carious tooth structure. Sound enamel usually does not undergo the same permanent discoloration, but porous, demineralized, or defective enamel may. The easiest way to create a bad SDF experience is to minimize this discussion before treatment. For anterior teeth especially, patients and parents should see photographs before consenting. The black color is also not proof of arrest. A treated lesion should become hard or firm and remain clinically inactive. A black lesion that stays soft or continues enlarging has not been successfully managed.
This makes follow-up part of the procedure, not an optional extra. The convenience of SDF is most obvious during application because the material can be placed quickly without an injection or handpiece. Its true value should be judged across the entire care pathway, including reassessment, reapplication, restorative treatment when necessary, and whether the patient’s overall caries risk actually improves. “Paint and forget” is no better a philosophy than automatic “drill and fill.”
For some patients, however, buying time is the treatment. A three-year-old with multiple active lesions who cannot tolerate conventional dentistry may be very different at age five. Arresting disease may postpone or prevent sedation, general anesthesia, pulpotomies, stainless steel crowns, or extractions. A frail nursing home resident with root caries may gain disease control without transferring to a conventional operatory. A patient with extensive active disease may have lesions stabilized first while the dentist develops a staged restorative plan. SDF can create treatment options where the previous choice was often between invasive dentistry and no dentistry.
Glass ionomer expands those options further. In the approach often called SMART, silver-modified atraumatic restorative treatment, SDF is used to arrest the lesion and glass ionomer is subsequently used to seal or restore it. This separates disease control from reconstruction. The dentist can stabilize the lesion biologically, then restore form, cleansability, function, or esthetics when that adds value.
The U.S. regulatory history is often misstated. In 2014, FDA cleared Silver Dental Arrest through the 510(k) pathway for treatment of dentinal hypersensitivity in adults over age 21. FDA did not clear the product for caries arrest. Using SDF to arrest dental caries developed as an evidence-supported off-label use. In 2016, Advantage Arrest received Breakthrough Therapy designation for caries arrest, but that designation was not the same as FDA approval for the indication.
Dental coding, however, has caught up with the clinical concept. CDT D1354 is “application of caries arresting medicament, per tooth.” It describes treatment of an active, nonsymptomatic carious lesion with a topical medicament without mechanical removal of sound tooth structure. The code is not technically limited to SDF. It describes the procedure rather than the product. It is also reported per tooth, not per surface. Treat five teeth and there may be five D1354 procedures, assuming each meets the clinical and payer requirements. D1355 is different. It describes preventive medicament application to a tooth at elevated risk before an active lesion requiring arrest is present.
The economics require more discipline than the clinical application. Several major federal dental plans now recognize D1354 as a covered preventive service, but benefit designs vary sharply. Delta Dental’s 2026 federal plan lists D1354 with zero in-network patient coinsurance and no obvious age restriction in the section reviewed. BCBS FEP Dental also provides zero in-network patient cost for eligible D1354 treatment but limits coverage to premolars and molars. United Concordia’s 2026 federal plan covers D1354 only through age 12, allowing two treatments per tooth per 12 months for ages one through six and one per tooth for ages seven through twelve.
Those examples prove that major carriers recognize caries arrest as a legitimate covered procedure. They do not prove that SDF is automatically a highly profitable procedure. “Covered at 100%” means the insurer pays 100% of its contracted allowance, not 100% of the dentist’s usual fee. The public brochures generally do not reveal the actual contracted D1354 reimbursement. A dentist considering an SDF program needs the real fee schedule, age limits, frequency restrictions, tooth restrictions, bundling rules, denial patterns, and staff costs before calculating revenue per visit or per clinical hour.
Original Medicare illustrates the opposite problem. Routine caries treatment remains generally excluded from Medicare Parts A and B, so ordinary D1354 treatment usually has no Original Medicare benefit. Medicare Advantage plans may include routine dental coverage, and Medicare can cover certain dental services that are inextricably linked to covered medical treatment, but those are different pathways. Medicaid may be more important for SDF because pediatric dental treatment is part of EPSDT. In Arizona, AHCCCS recognizes D1354 in its dental coding infrastructure, although appearance on a fee schedule does not by itself guarantee coverage or payment.
Delegation may have as much impact on SDF economics as the procedure fee. State law controls who can apply the material and under what supervision. Arizona provides a useful example. In 2019, the Arizona State Board of Dental Examiners specifically determined that SDF is a topical fluoride within the scope of dental assistants and dental hygienists. A regular Arizona dental assistant can apply topical fluoride under direct supervision, meaning the dentist is physically present in the office. An Arizona dental hygienist can apply preventive and therapeutic agents under general supervision, which can allow the dentist to be off-site while remaining responsible and available for consultation. Affiliated-practice hygienists have an even broader pathway for delivering care in qualifying community settings.
Expanded Function Dental Assistants require more caution. Arizona law clearly permits an EFDA to apply fluoride varnish under general supervision, but the statute says “fluoride varnish,” while SDF is a solution. An EFDA can clearly apply SDF under direct supervision because an ordinary dental assistant already can. Whether an EFDA may apply SDF under general supervision with the dentist off-site deserves written clarification before a practice builds a business model around it.
This is where SDF becomes operational rather than theoretical. A dentist may diagnose the disease, determine which lesions are appropriate for arrest, obtain informed consent, and establish follow-up. In states that permit delegation, trained auxiliaries may perform the application. That can change scheduling, expand outreach, reduce the dentist’s chair time, and make school, nursing home, special-needs, and community programs more practical. It also requires good protocols because delegation does not eliminate diagnosis, informed consent, documentation, quality control, or reassessment.
The temptation with SDF is to turn a useful clinical advance into a crusade against restorative dentistry. The stronger argument is more modest. SDF gives dentists another point of intervention. Some lesions can be arrested before they require conventional restoration. Some patients can be stabilized before definitive treatment. Some children may avoid general anesthesia. Some elderly patients may keep teeth that would otherwise progress untreated. Other lesions will still need restorations, crowns, endodontics, or extraction.
Silver diamine fluoride does not replace restorative dentistry. It changes the point at which restorative dentistry becomes necessary.
How many teeth are we restoring today because we never gave disease arrest a chance?
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