Silver diamine fluoride's FDA clearance (K102973, 2014): cleared for sensitivity in adults over 21; caries arrest is off-label

What it says#

The FDA's 510(k) database entry for K102973 is short. Device name: Silver Dental Arrest. Device classification name: diammine silver fluoride dental hypersensitivity varnish. Applicant and correspondent: Cooley Consulting, Inc., Wyoming, Ohio, contact William Cooley. Regulation number 872.3260, product code PHR, dental panel. Date received October 6, 2010; decision date July 31, 2014; decision: substantially equivalent. Submission type traditional, not reviewed by a third party, not a combination product, and filed with a 510(k) statement rather than a summary, which is why the public file consists of the clearance letter and the indications-for-use page.

The letter, dated July 31, 2014 and addressed to ADP Silver Dental Arrest, LLC in care of Dr. Cooley, says the FDA reviewed the premarket notification and determined the device is substantially equivalent, for the indications for use stated in the enclosure, to legally marketed predicate devices, so it may be marketed subject to the general controls of the Act: registration and listing, good manufacturing practice, labeling, and the prohibitions on misbranding and adulteration. It lists the regulation name as cavity varnish and the class as Class II. (The letter prints the regulation number as 872.3620; the database record, the product classification and the eCFR all give 872.3260, which is the cavity varnish regulation.) The enclosure is the one-page indications-for-use form: "Treatment of Dental Hypersensitivity. For use in adults over the age of 21." The prescription-use box is checked; the over-the-counter box is not.

The classification behind product code PHR describes the device as applied to tooth enamel to block dentinal tubules for the purpose of reducing tooth sensitivity, a liquid or gel that precipitates on application to produce a physical blockage of the tubules, Class 2, cleared by 510(k), reviewed by the Division of Dental and ENT Devices. The regulation it sits under, 21 CFR 872.3260, identifies cavity varnish as a compound intended to coat a prepared cavity before restorative material is placed, classified Class II with special controls.

What the profession does with the product is different from what the label says, and the ADA says so in its own words. Its silver diamine fluoride topic page describes a colorless or blue-tinted alkaline liquid, 38% weight per volume, roughly 24.4% to 28.8% silver, 5.0% to 5.9% fluoride and 8.0% ammonia, and states that the FDA has classified SDF as a Class II medical device cleared for the treatment of tooth sensitivity, the same type of clearance as fluoride varnish, professionally applied; and that although its use in caries control and management has been reported, it is not specifically FDA-labeled for that indication. The page then summarizes the evidence for arrest, including the ADA's 2018 nonrestorative guideline, whose panel suggested clinicians prioritize 38% SDF applied biannually to arrest advanced cavitated lesions on coronal surfaces of primary teeth and extrapolated the same suggestion to permanent teeth, and the 2020 House of Delegates statement quoted above, which adds that arrest requires diagnosis and monitoring by a dentist, a patient-specific treatment plan, informed consent covering options, side effects and follow-up, and that application may be delegated to trained allied staff where state law allows.

Who it applies to#

The clearance itself binds the manufacturer and its distributor: what they may claim, how the product is labeled, and who may buy it (prescription use, dental professionals). Elevate Oral Care's safety data sheet for Advantage Arrest, issued April 17, 2015 and revised in 2023, lists the product use as dental, for the prevention and treatment of dentinal hypersensitivity, for use by dental professionals; the trade announcement of April 27, 2015 described it as the only silver diamine fluoride cleared for use in the United States and Elevate as its exclusive distributor.

For a dentist, the clearance defines the on-label use: sensitivity, adults over 21. Everything else, and in practice most of what SDF is used for, is off-label prescribing by a licensed clinician, which the ADA's statement and guideline support in defined circumstances and which the FDA's clearance does not address. The ADA's conditions are the ones that reach the operatory: a dentist's diagnosis, a treatment plan, consent that names the alternatives and the black staining, follow-up, and delegation only as the state allows.

The Breakthrough Therapy designation reported in November 2016 sits on a different track. The FDA describes the designation as a process designed to expedite the development and review of drugs intended to treat a serious condition where preliminary clinical evidence suggests substantial improvement over available therapy; the trade report said it was granted to Advantage Arrest for the arrest of tooth decay in children and adults on the basis of ten randomized trials in about 1,500 subjects followed for one to three years. It is a step in a drug approval pathway, not an approval, and at this check the device clearance still reads sensitivity and the ADA still calls arrest off-label.

What changed#

Before July 2014 there was no silver diamine fluoride product cleared for the US market; the trade announcement of the launch spoke of more than eight years of work to get there, and the FDA record shows the file open from October 2010. The clearance put a 38% SDF solution in US operatories, and from April 2015 it was available. What followed was the guideline work: the ADA's 2018 nonrestorative guideline placed 38% SDF first among the options for advanced cavitated coronal lesions in primary teeth, and the 2020 House of Delegates statement gave the profession a policy that both acknowledges the label and endorses the off-label use with conditions. The label itself has not moved.

Where the source is#

The link under the title is the FDA's 510(k) database record for K102973, and the PDF listed first under downloads is the FDA's three-page file: the clearance letter and the indications-for-use form (a scanned document; the indications sentence is legible on the form). The product classification page for code PHR and the eCFR text of 21 CFR 872.3260 are the two regulatory definitions. The ADA's silver diamine fluoride topic page carries the off-label statement, the 2020 House of Delegates statement and a link to Elevate's safety data sheet. The April 2015 availability date and the November 2016 Breakthrough Therapy report come from two trade publications, Dimensions of Dental Hygiene and Decisions in Dentistry, because neither the FDA nor Elevate publishes a page on the designation; treat those two dates as reported rather than official.