Using silver diamine fluoride as a new caries management solution
Silver diamine fluoride (SDF) has been used all over the world for decades. The FDA approved its use in the U.S. in 2014 to treat hypersensitivity. However, it’s also well-known for its off-label use for dental caries management. It’s not yet in widespread use stateside; however, dental professionals are learning that with all the benefits it presents with few downsides, SDF could provide a significant new solution for conservative treatment of carries in specific patient populations.
“It’s something you can do at a school, in a nursing home, you could do it in a doctor’s office. You could use it on a mission trip in the middle of some rural area,” says Dr. Nathaniel Lawson, DMD, Ph.D., division director of division of biomaterials at the UAB School of Dentistry.
While officially an off-label use, SDF handles dental decay with a more conservative approach. Per the fact sheet by the California Dental Association, silver’s antibacterial properties combined with fluoride’s ability to remineralize tooth enamel slows or stops dental decay.
The American Academy of Pediatric Dentistry (AAPD) published a guideline in October 2017 that recommended the use of 38% SDF to treat caries. It’s ideal for patients who can’t get the dental treatment they need for various reasons (e.g., too young, too old, too sick, too remote without regular access to dental care, etc.).
Dr. Lawson works in an HIV clinic once a month. Sometimes his patients have been in the hospital and haven’t been able to take care of their teeth. Some of them could have as many as 25 cavities when he sees them. SDF buys the patients some time.
“I’ll stop all the cavities from getting any bigger, and I will see them every other week until all their fillings are done,” Dr. Lawson explains.
Dr. Lawson also says it’s easy to use if a child can’t sit still long enough for treatment. In these cases, the dentist applies SDF to all of the child’s cavities. Then, the child has time to mature or build rapport with the dentist without the cavities worsening. It can also help when the child is on a wait list for surgical procedures that require general anesthesia, which can be a lengthy wait, particularly for Medicaid patients.
SDF also helps geriatric patients who could have cavities that are difficult to treat (e.g., on the root of the tooth or under other dental appliances). The dental professional can apply SDF and, in some cases, never fix the cavities. Dr. Lawson emphasizes that follow-up application is needed every six months to maintain the effects.
“If the patient in a remote area has 10 fillings, and you don’t know when the next dentist is going to be there to finish the case, SDF is a great way to get people out of pain and stop the disease from progressing as well as help with sensitivity in the meantime,” she says.
State law dictates who can use SDF on patients
Aberle works for a community health center as a school-based dental hygienist. She would like to use SDF with her students, but she can’t. The state of Colorado where Aberle practices has yet to sign into law that SDF falls under a dental hygienist’s Scope of Practice.
Aberle, who is also the executive administrator for the Colorado Dental Hygienists' Association, worked with the team that wrote the law for the state legislature that will change that. After a significant process, it has passed the state’s senate and house and, on March 22, 2018, was signed into law by the governor. A Rulemaking hearing through the dental board will finalize the specifics of its use, which will happen within 90 days.
Colorado is unusual in this instance, Aberle explains. Most states treat SDF like the other fluoride varnishes and rinses that dental hygienists administer. However, hygienists should always check state law before using SDF.
A new product representing a new approach
SDF represents a new way of approaching caries management. Dr. Jason Goodchild, DMD, director of clinical affairs for Premier Dental Products Company, remembers a time when the only way to manage caries was removal and restoration. As an associate clinical professor at Creighton University School of Dentistry and also an adjunct assistant professor at Rutgers School of Dental Medicine, Dr. Goodchild likes the options that SDF provides tomorrow’s clinicians.
“When I was in dental school 20 years ago, it was an instant failure on your board exam if you left caries in the preparation. There was no gray area there. It was removal 100 percent, and that’s it. Now, we see things a little bit differently, meaning tooth preservation, preventative measures and earlier caries detections are all very important. That’s where SDF comes in. It opens up options of partial or no caries removal as a way to treat decay for certain situations,” Dr. Goodchild says.
However, Dr. Goodchild warns that it’s not a “magic bullet.” Despite its numerous advantages, success rates with SDF are not 100 percent. In fact, there’s some discussion about how much of the bacteria SDF kills and how long it lasts. All proponents of SDF recommend follow-up applications at least twice a year. Dr. Goodchild’s practice follows the first application with a second application after three weeks, and then every six months after that. He also recommends covering up the lesion right away with fluoride varnish to optimize the substantivity of SDF.
More studies are needed to determine standardized guidelines and protocols. The UCSF School of Dentistry presents a systematic review for SDF, a clinical protocol and a consent procedure. The UCSF study finds the every-six-months protocol “outperformed all minimally invasive options” for decay restoration and was less expensive. SDF has preventive properties for other teeth that was only outperformed by dental sealants. However, sealants were much more expensive than SDF. In the UCSF study’s conclusion, the team describes SDF as “a powerful new tool in the fight against dental caries, particularly suited for those who suffer most from this disease.”
Advantages of SDF
Application of SDF is simple. The liquid comes in a small bottle, and dental professionals use a couple of drops in a small disposable container and apply with a brush. The UCSF study advises dental professionals to use a “cautious approach” and isolate the area with cotton or gauze and dry the lesion before application. It also supports giving the solution one to three minutes to soak into the tooth. However, if that time frame is beyond the limits of compliance that a patient can muster (as it may be in very young children), a few seconds also seems to be sufficient for arresting carries.
In this video. Dr. Jeremy Horst, DDS, Ph.D, the lead author of the UCSF study, demonstrates how to apply SDF using the cautious approach.
SDF’s on-label use is as a tooth desensitizer. Aberle explained that this benefit gets overlooked. However, people with sensitivity have a hard time keeping up with proper nutrition, focusing and sleeping.
“To get people out of pain and reduce that sensitivity is a huge benefit. We always talk about stopping the cavity, which is great, but getting people out of pain quickly is also important,” she says.
SDF is also cost-effective. A bottle costs around $150; individual packets can run $120 for 30 packets.
“That brings it to $4 a patient, and you can get three to four teeth out of that. For public health applications, it’s pretty good,” Dr. Lawson explains.
Disadvantages of SDF
SDF stains decay black a couple of days after application. Although the staining is a disadvantage, it’s also a benefit, acting like a caries detection solution. However, the staining can make patients or their parents less enthusiastic about the treatment.
“Some parents will see that balance between trying to treat a child versus having a black tooth and say, ‘No big deal. I’d rather see black on the tooth than having them sit through the dental work at a young age or even having to go to the operating room or go under general anesthesia to get this work done.’ For others, it’s a no-go,” Dr. Goodchild says.
Dr. Goodchild uses the SMART (Silver Modified Atraumatic Restorative Treatment) technique with his patients, which can cover up the staining.
“If you want to do the SMART technique with traditional glass ionomer (not light cured), then spoon out the caries or drill at a slow speed to get rid of the easily removable caries, which can be done without local anesthesia. Apply SDF, then you restore with traditional glass ionomer, which not only fills in the hole but also can help cover up the black color,” Dr. Goodchild explains.
Aberle feels that dental professionals put a lot more importance on the staining than patients do. Elderly patients and parents of young children want to stop the disease and relieve the pain or forgo the operating room.
“We have to try not to let the staining scare us away from the benefits of it,” Aberle says.
Another disadvantage is that treating a cavity with SDF doesn’t restore teeth back to their healthy state.
“It’s not a final solution,” Dr. Lawson says. “It’s an interim solution to stop the cavity.”
SDF has also been known to stain inflamed gum tissue. It shouldn’t be applied where there is broken or ulcerated tissue as the staining could be permanent.
The use of SDF is new in the U.S., which can be challenging when billing. Its off-label use could also pose a problem when trying to code the treatment. Dr. Lawson has seen the following four codes used:
D-1354: Interim Carries Arrest
D-1208: Topical Application of Fluoride
D-1999: Unspecified Preventative Procedure
Dr. Lawson cautions clinicians to be sure to cover all the essential details in the pretreatment interview. SDF isn’t right for patients with a silver allergy, nor is it good for those averse to fluoride treatments.
“Drinking water has one part per million of fluoride. Toothpaste has 1,000 parts per million. SDF has 44, 000 parts per million of fluoride, making it 44,000 times more fluoride than water and 44 times more than toothpaste,” Dr. Lawson says. “So, it does have a high concentration of fluoride.”
“Some people are more conservative with how much fluoride they apply to their teeth. So that’s always something to include in the conversation,” Aberle agrees.
The American Dental Association’s (ADA) November 2017 issue of Professional Product Review analyzed some of the properties of SDF for treating or preventing caries in two articles. First, it featured a study on silver diamine fluoride by researchers from the ADA Science Institute and the University of Michigan. In the second article, a team of dentists covers clinical indications for SDF, clears up some questions about it and addresses some clinicians’ concerns.
At the time of publication, only one SDF product was on the market, Advantage Arrest™ by Elevate Oral Care, LLC. However, as the use of the product grows in popularity, new products are sure to hit the market, including two-step systems currently used in Australia that address the esthetic concerns of SDF. In these systems, potassium iodide (KI) is applied to counteract the silver properties that cause the staining.
“It’s not an option in the U.S., but it could be one day,” Dr. Lawson says.
Awareness and use of SDF continue to grow, giving dental professionals another option for caries management and, for some patients, the best possible option.
“It is very straightforward and a quick procedure. It’s something that can be done in non-traditional settings. It can be done on children that can’t sit still very long. It can be done on elderly who aren’t able to sit in a dental chair or wheelchair-bound patients,” Aberle says. “It’s very simple to apply. It’s very quick and can be used for a lot of people who might not be able to seek traditional dental care.”