Trends in Silver Diamine Fluoride (SDF) as Preventive Fluoride Treatment and as a Caries Arresting Agent:
Another trend for caries management provided by dental hygienists working with underserved populations, is the use of Silver Diamine Fluoride (SDF), which has been shown to be more effective than fluoride varnish for caries control.
The use of silver diamine fluoride (SDF) for management of dental caries has gained considerable attention due to recent regulatory clearance in the United States. The primary focus of policies, presentations, and publications has been the arrest of caries lesions (cavities) because of the material’s unique ability to non-invasively achieve this elusive and clinically important goal. However, SDF also has proven efficacy in prevention, ie, decreasing the incidence of new caries lesions.
Analysis of nine clinical trials in children shows that SDF prevented 61% of new lesions compared to controls. To prevent one new caries lesion, clinicians need to treat four primary teeth (one patient) or 12.1 permanent molars (three patients) with SDF. The preventive effect appears to be immediate and maintains at the same fraction over time.
Direct comparisons of SDF applied once per year with alternative treatments show that SDF is more effective than other topical fluorides placed two to four times per year and more cost-effective than dental sealants.
Enamel lesions may be even more responsive than cavitated dentin lesions. Annual application of SDF to high-risk surfaces (eg, mesial surfaces of permanent first molars where the distal surface of the second primary molar is carious) in patients with any risk of new caries lesions appears to be the most cost-effective approach available to prevent dental caries. SDF is an underutilized evidence-based preventive agent for dental caries.
Recommended Application Protocol
Prior to application of SDF for prevention of new caries lesions, caregivers or patients should be properly informed of the risks, benefits, and alternatives of SDF. Risks should include photographs of SDF-induced stains, appropriate to prevention situations. Benefits should include a description of the size and number of new caries lesions anticipated without SDF and the difference in time, cost, and experience of the alternative treatments.
Prior to SDF application for prevention, prophylaxis is neither required nor advisable. Careful application of petroleum jelly (ie, Vaseline®) to protect the gingiva may be considered but petroleum jelly on the tooth surface will decrease effectiveness.
Selected surfaces for prevention should be isolated with cotton, dried with cotton or compressed air, and one to two drops of SDF should be spread across all of the highest-risk surfaces in the mouth with a microbrush.
Wetting of the surface is sufficient, and further isolation time for soaking in is not required. Excess should be removed with cotton. Some clinicians choose to cover treated areas with a varnish, such as a fluoride varnish, to prevent dilution by saliva.
Once or twice per year application in a population with a high caries rate of children. t is as yet unclear from available studies whether re-application of SDF is necessary to maintain the preventative effect of the first application, or if so, how often re-application is indicated.
Annual reapplication of SDF has been found to be superior or equivalent to multiple applications per year of other contemporary topical preventives. Considering the patterns of clinical outcomes observed in the published trials in children, annual re-application of SDF is recommended.
Because there is considerable evidence that risk factors correlate to incidence of new lesions, it would be logical to apply more frequently for patients with salivary dysfunction and infants and toddlers with very high caries risk should be treated more frequently due to the rapid influx of high-risk surfaces.
Selection of Surfaces
SDF should be placed on the highest-risk surfaces as a priority. Usually, pits, fissures, and proximal surfaces have the highest risk. However, all surfaces are at similar risk in the upper anterior teeth of infants, exposed root surfaces bear the highest risk in older adults, and teenagers can suddenly develop proximal lesions on all posterior teeth.
Thus, the pattern of lesions for the patient's demographics should be considered. Additionally, the patient's caries risk and esthetic concerns should be balanced in deciding which surfaces to treat.
As of Jan. 2021, CDT Code D1355 as a Caries Preventive Medicament Application is billed on a "Per Tooth" basis and is the appropriate billing code when SDF is used for prevention of new lesions.
Considerable evidence supports the annual use of SDF for preventing new caries lesions in primary teeth and permanent molars. Multiple clinical trials show higher levels of prevention with less frequent applications of SDF than other topical therapies such as fluoride varnish.
SDF seems to have a modestly less preventive effect but substantially greater cost-effectiveness than either resin or glass-ionomer cement sealants for preventing new lesions in permanent molars and is also easier for patients to tolerate and can be more quickly applied than other preventive materials.
Unlike sealants, SDF can be placed on any tooth surface, and the fluoride released may protect proximal surfaces not directly treated.
According to the May 2018 Board of Dentistry Minutes, Dental Hygienists in GA may use SDF as a fluoride treatment.
SDF as a Caries Arresting Agent:
SDF is a non-invasive, interim inexpensive medicament that is applied topically. It is 38% SDF, a silver fluoride salt made soluble in water through the addition of ammonia. SDF received Food and Drug Administration approval in 2014 as a device for treating dental hypersensitivity.
When teeth with arrested dental decay are not subsequently restored with dental fillings or full coverage crowns, studies show it is advisable to reapply SDF every six months.
With a fluoride concentration of 44,800 parts per million, SDF is nearly twice the strength of commercially available 5% sodium fluoride varnishes used in primary care.
In the 2019 Journal of Public Health Dentistry article "Projecting the Economic Impact of Silver Diamine Fluoride on Caries Treatment Expenditures", co-authored by Dr. Nicoleta Serban, a Professor at Georgia Institute of Technology, the article reported that application of SDF as a caries management strategy could save Medicaid Programs money by averting expensive caries treatment options.
Dr. Serban compared the cost savings from NC (since it is very similar in terms of demographics to GA ) and estimated an expenditure reduction for GA’s Medicaid Program can be anywhere from 15 million to 48 million over a 3 year period.
Patients who may benefit from SDF include those:
With high caries risk who have active cavitated caries lesions in anterior or posterior teeth;
Presenting with behavioral or medical management challenges and cavitated caries lesions;
With multiple cavitated caries lesions that may not all be treated in one visit;
With dental caries lesions that are difficult to treat; and
Without access to or with difficulty accessing dental care.
Criteria for tooth selection include:
No clinical signs of pulpal inflammation or reports of unsolicited/spontaneous pain.
Cavitated caries lesions that are not encroaching on the pulp. If possible, radiographs should be taken to assess depth of caries lesions.
Cavitated caries lesions on any surface as long as they are accessible with a brush for applying SDF. (Orthodontic separators may be used to help gain access to proximal lesions.)
SDF can be used prior to restoration placement and as part of caries control therapy. Informed consent, particularly highlighting expected staining of treated lesions, potential staining of skin and clothes, and need for reapplication for disease control, is recommended.
Training for SDF placement may be dependent on requirements by each state Board of Dentistry. According to the May 2018 Board of Dentistry Minutes, Dental Hygienists in GA may use SDF, but as a fluoride only.
If the supervising dentist would like SDF used as a caries arresting agent they must apply the initial application, and the dental hygienist may use it as a fluoride agent thereafter.
The following video provides an example of an SDF Application: