Silver Diamine Fluoride: The little known conservative caries management tool

The FDA cleared Silver Diamine Fluoride (SDF) in 2014 for treating hypersensitivity. However, research shows SDF is also useful for its off-label use of dental caries management. 

Jeremy Horst, DDS, Ph.D., and the UCSF School of Dentistry in their paper “UCSF Protocol for Caries Arrest Using Silver Diamine Fluoride: Rationale, Indications, and Consent,” described SDF as a powerful new tool in the fight against dental caries. The UCSF study in 2016 found application every six months was the best performing minimally invasive option for decay management. In addition, the researchers said SDF served as a preventative material for teeth without decay as well, although, in this use, dental sealants outperformed SDF. 

Since then, research on SDF has continued. Dr. Horst says that more trials around the world and in the US have produced data that supports SDF’s efficacy and safety. Currently, he says there is a clinical trial going on in New York, Iowa, and Michigan that could be influential in SDF getting the FDA’s approval to be the first drug approved for treating cavities. Meanwhile, it is already approved for caries use in other countries such as Canada and Japan.

“Perhaps most importantly, we have now completed safety trials. After application of SDF to large cavities in three to five-year-old children, in ours and another independent study, all the kids were fine,” Dr. Horst says. 

Dr. Horst described SDF’s fluoride and silver components as producing a double-whammy effect of fighting decay. The combination of silver’s antibacterial properties and fluoride’s remineralization effects make the tooth harder by incorporating into the tooth structure and making the tooth more resilient to decay. SDF then slows or stops decay altogether, although patients and providers may choose to restore the tooth as well. With regular SDF retreatment, no further therapeutic work is necessary in approximately 80 percent of cases. 

Dr. Horst says his team has been doing a lot of basic science, taking patient samples and analyzing them in the lab to try to understand the mechanisms of how Silver Diamine Fluoride works. The team learned that while there are fewer bacteria overall, the relative amount of each type of bacteria stays the same  

“There’s a lot less of all the bacteria, but the amounts of each kind all go down evenly, which was surprising to us,” Dr. Horst says. “Changes in the microbiome can be dangerous, so this actually speaks to the safety of SDF.”

Growing awareness leads to new solutions

As awareness of SDF’s off-label use spreads, dental professionals discover another option for caries management that is the best possible option for treatment for some patients. From schools to nursing homes to community outreach events, SDF provides a conservative approach to treating dental decay for patients who might not be candidates for traditional restorative care because of severity of decay, economic conditions, age, behavioral issues, or medical conditions.

Steven Parrett, DDS, FAGD, has a private practice in Chambersburg, Pa., and works with his community at a local church at an event called Diaper Depot. The event is all-volunteer and run by Dottie Bush, along with more than 50 community volunteers who give their time and resources. The program provides diapers and a hot breakfast, as well as food and other essentials, to around 200 to 300 people in the community who need them. Dr. Parrett does a dental screening clinic there, as well. 

“Anyone who has concerns about their teeth, I’ll look at them and tell them what I think and make some recommendations as far as whether they should get a cleaning, a tooth extracted, or if they need to have some X-rays for a diagnosis,” Dr. Parrett says. “If I see decay, I apply Silver Diamine Fluoride.”

Dr. Parrett sees using SDF as a disclosing solution as an essential aspect of the SDF conversation. It has changed the way he diagnoses in areas where the decay isn’t apparent. 

“We have this infamous term we used to use: We’re going to watch it. My question is, watch it what? Get worse? Get better? Stay the same? I don’t know,” Dr. Parrett says. “Any watch areas we have, we put SDF on it. If it is active, it will turn black, and then we can decide if we’re going to retreat it with SDF or restore it.”

Betty Kabel, RDH, BS and past president of the American Dental Hygienists Association, says SDF has been a help in her school-based program that treats children from ages three to 12 years old. Working in Northwest Florida, she and the dental hygiene team have seen an increase in primary decay, and, in some kids, decay in the permanent teeth as well. 

Many times Kabel’s patients are on a waiting list for treatment from a Medicaid provider, which she says could be a wait anywhere from three to five weeks. They use SDF as a stop-gap measure to arrest the decay while they wait for restorative care. In her program, they see patients in the fall months, and then again in the spring, which is a good schedule for retreatment. 

“We pull those same children again and reapply it if they have not had it restored,” Kabel says. 

Also, because the program does not include radiographs, they diagnose what they can see. When they see something that might indicate decay but is not 100 percent clear, Kabel and the team will apply SDF and recheck it the next time they see the patient for visual changes. An additional benefit here is the SDF protects against decay in the area where it was applied. 

“Since we were already providing other preventative treatment, this has been a great supplement to be able to provide the service,” Kabel says of using SDF in the school-based program.

Using SDF has been particularly helpful when treating patients who move a lot, especially for the transient Hispanic population that uses Kabel’s program for dental care. When applied to their permanent molars, SDF helps protect the patients against future decay.

“We’re able to put SDF on there and arrest that decay. At least we know that it stopped because we don’t know if we will see them again,” Kabel explains. “Sometimes we see them in September, and then, when we go back in January, they’ve already moved. So, that’s been an added benefit for them.”

In his private practice, Dr. Horst uses SDF at the examination for nearly all cavities, particularly those he will restore. He describes this as the first step in the two-day SMART (Silver Modified Atraumatic Restorative Technique) protocol for small or large Class I restorations-at the second visit he merely cleans the tooth with pumice, applies conditioner, rinses, then places a glass ionomer filling. This method has enabled him to treat countless toddlers and fearful patients without use of numbing or rubber dams. His first fillings using this simple approach were placed in 2014 and are still in the baby teeth that will exfoliate within the next year.

“It would not be possible without using SDF to harden the cavity first. The SDF-arrested area is twice as hard as healthy dentin, so why put a drill on it?” Dr. Horst says.

SDF can help patients on the other end of the age spectrum, as well. Geriatric patients with difficult-to-treat cavities on the root or under another dental prosthesis can use SDF to delay treatment but arrest caries in the meantime. Also, it can help for patients who are unable or unwilling to treat the decay. 

Cindy Yanora, RDH at Stuart Periodontics in Florida, uses SDF with her elderly patients. Many times she describes it as buying time while they work through whatever is preventing them from moving forward with the restorative work they need. 

“I always try to get them back to the general dentist to do the restorative work,” Yanora says, regarding patients where she uses SDF to arrest decay. 

Yanora describes a case where a woman in her late 70s was having restorative work on an existing crown and having a new implant placed at the same time, but not for a few months. Near the margin, the dentist had repaired the crown already. The patient complained of sensitivity around that repair. 

“I could feel it was soft around that repair,” Yanora says. “So, I put SDF there because she’s probably months out before she does the crown on that one.”

Also, SDF can provide another option for removal and restoration therapy for caries management. However, retreatment is necessary to maintain its effects. 

Yanora says SDF comes in handy with patients suffering from Xerostomia. The dry conditions contribute to early decay around crown margins. After cleaning the plaque, she applies SDF to protect against further decay.

“Nursing homes are using it now,” Yanora says. “It would make total sense for patients that can’t be transported. A lot of people, it’s just too much to be able to go through a procedure, but SDF would prevent them from being in pain.”

The disadvantages of SDF

There are some drawbacks to using SDF. The most notable disadvantage is the staining that occurs. After application, decay turns black. 

SDF can also stain inflamed gingiva. As a result, SDF is not applied to broken or ulcerated tissue areas because the staining could be permanent. 

SDF is not for everybody. You should not apply it to patients with allergies to silver. Also, patients who are fluoride-treatment averse would not like the high concentration of fluoride present. 

You should discuss all of these disadvantages in a pretreatment interview. With minors, parents should sign a waiver that acknowledges these risks to avoid problems later. 

Yanora says the staining scares some people away from using it, even other hygienists. However, she thinks that fear is unnecessary. Often, she says, you are using it in areas that most people can’t see. Many times, she uses her explorer to see if it worked because she can’t see the area where she applied it.

“It doesn’t turn the tooth black; it turns the caries black,” Yanora says. “Just don’t be afraid of it. Patients are very willing to use it.”

In Kabel’s school-based program, they have seen almost 1,100 children for more than a year and a half and haven’t had any negative consequences from its use. 

“As far as any side effects or parental concern about the discoloration or not having consent forms signed, that has not been a problem,” Kabel says, adding they have about a 50 percent return rate on consent forms to use SDF.

Dr. Horst agrees that staining is not a significant deterrent from treatment. He estimates that two out of 600 patients have declined SDF in the past year, and that wasn’t because of the staining. 

“We find that patients don’t care about staining nearly as much as dentists,” Dr. Horst says. 

Kabel especially appreciates how SDF helps some kids who otherwise might have to be hospitalized and put under general anesthesia to have their teeth restored. It also benefits kids who are afraid of the dentist. Furthermore, by arresting the decay in the primary teeth, SDF helps them reduce the incidences of decay in their permanent teeth.

“I don’t know why anyone would not want to use SDF because it’s probably the best thing we’ve done in our schools.”

Dr. Parrett explains the risks of staining with SDF and has the patients or their legal guardians sign consent forms. He also encourages them to come back the next month for retreatment if they haven’t had the restorative work done yet. 

One of his patients is a six-year-old girl named Macie, whom he describes as a real happy kid that he has been treating with SDF since she was two. Macie was facing surgery under general anesthesia and chrome crowns as a toddler. Instead, Dr. Parrett arrested the decay with SDF. Soon, her permanents will come in, which will give her a chance to “learn to cut out the gummy bears,” Dr. Parrett says. 

“That’s a whole other area that SDF is going to help with; eliminating the trauma that patients would have experienced with the old drill and fill,” Dr. Parrett says. 

Dr. Parrett is also actively campaigning for the use of SDF in community screenings. In particular, he wants to use SDF to buy time for patients that attend a local FQHC (federally qualified health center), which has a six-month wait time for routine care. 

“These patients could receive immediate applications of Silver Diamine Fluoride and schedule for return visits to the Screening Clinic to retreat,” Dr. Parrett writes in his proposal to the CEO of Keystone Health. 

“It is the best thing that has been added to our regimen to help kids or help anyone at high risk for decay. I would recommend anyone who can use it, whether you are private practice or public health, nursing homes, or anything else, I would use it,” Kabel says. 

“It’s a social justice product because it’s so easy to do and so easy to receive as a treatment,” Dr. Horst says, “and to make a huge difference in the trajectory of the disease.”

References

1. Horst, Jeremy A et al. “UCSF Protocol for Caries Arrest Using Silver Diamine Fluoride: Rationale, Indications and Consent.” Journal of the California Dental Association vol. 44,1 (2016): 16-28. Accessed via web. 17 October 2019. < https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4778976/>.

2. Ibid.

3. Ibid.

4. “American Academy of Pediatric Dentistry Fact Sheet Silver Diamine Fluoride.” Elevateoralcare.com. Web. 18 October 2019. < http://www.elevateoralcare.com/site/images/AAPDSDFmedicaid.pdf?promocode=&promocodeaction=overwrite>

Applying Silver Diamine Fluoride

As of now, there are no standard-of-care guidelines and protocols for SDF. However, many practices will apply two consecutive months followed by a third six months later, and then periodically from there. Some dentists also apply a fluoride varnish over the SDF to keep it on the lesion longer and optimize its effects.

Elevate Oral Care, LLC, in West Palm Beach, Fla., makes the SDF solution available in the US called Advantage Arrest™. The one-step system is a blue topical agent that is tinted to improve placement visualization and comes in a small bottle with a brush. 

The UCSF Study recommends isolating the area with cotton rolls or gauze to dry the lesion before you apply the solution. After application of a couple of drops of the solution to the lesion, you should allow from one to three minutes for the SDF to absorb into the tooth is ideal. However, in some cases, particularly with unruly patients in the chair, a few seconds seems to be enough to arrest caries. 

Since the 2016 study, Dr. Horst and his research team have learned you do not have to rinse the SDF as was initially suggested. At the time of the original study in 2015, there was not enough safety data for children, and the research team didn’t want to endanger the children in the study, which is why a rinse was suggested. Now, however, there have been enough safety studies that everyone feels comfortable eliminating the rinse step. 

“It was kind of silly that we suggested the rinse because you were putting medicine in and then taking it away a little bit,” Dr. Horst explains. “Now, there are multiple studies of safety data for young children, so we all fine about not having the rinse.”

Dr. Horst says studies show frequent reapplication at the beginning of the SDF protocol, followed by annual or bi-annual retreatments, has shown the best results. But for how long?

“We don’t have any information on that just yet,” Dr. Horst says. “Pediatric dentists would say once the teeth fall out, but that could be a long time.”

Our experts have a couple of tips on how to use SDF in the tight spaces of the oral environment. Kabel uses the microtip to get the SDF into small areas. Dr. Parrett uses the natural capillary action in close contact areas to allows the SDF to flow in many cases. However, in a few instances, Dr. Parrett and his team will apply on the buccal side of the tooth and use high-volume suction on the lingual to pull the solution through. 

“You might use a little bit more than you would have. But it’s still a lot better than cutting into the tooth that may not need it, and the cost is minimal,” Dr. Parrett explains.

Dr. Horst says SDF can be the first part of a two-step SMART (Silver Modified Atraumatic Restorative Technique) filling. First, you use the SDF on the lesion and allow it to absorb and stain, then, at a second appointment a week later, you use the drill on the margin without any local anesthetic and then place an opaque glass ionomer cement over it to manage the stain.

The billing for SDF is established already. Per a fact sheet from the American Academy of Pediatric Dentists, the CDT code is D1354-interim caries arresting medicament application.  As of January 2018, you record it as a per tooth application. 

Dr. Parrett sometimes applies SDF three times within a two-week period. He says D1354 covers all three of those applications and the charge is $23. By comparison, when they apply SDF to the full mouth to decrease sensitivity, Dr. Parrett’s office uses code 9910 and the charge is $64. 

Elevate Oral Care conducted a study this summer that revealed 32 state Medicaid dental plans currently reimburse this code and procedure. However, California, Texas, and New York, three of the top four states by population, are not among them. Dr. Horst says more private insurances cover D1354 than state Medicaid programs. 

“When SDF first was approved by the FDA, many people were concerned that this would be a treatment primarily for poor children. They thought this would create a two tiered system,” Dr. Horst says. “The reality is that children covered by Medicaid in California, Texas, and New York do not have access, but most private insurance plans do, so the rich kids get it, and the two-tiered system gets worse.”

Additional Information on SDF

Two articles from the American Dental Association’s (ADA) November 2017 issue of Professional Product Review analyzed SDF’s treatment and prevention properties. 

To access the ADA Professional Product Review November Issue visit the website at: https://www.ada.org/en/publications/ada-professional-product-review-ppr/current-issue (An ADA log-in is required.)

Elevate Oral Care has the Fact Sheet for the American Academy of Pediatric Dentistry available on their website. 

To download the PDF, go to: http://bit.ly/AAPDFactsheet