By Dr. Kyla Romard
NSDA Clinical Affairs Manager

As the Canadian Dental Care Plan (CDCP) enters its initial rollout, the NSDA has been receiving many calls from the general public, eager for specific dates and details — information which, at the time of writing, we do not have.

An unintended consequence of this wait is that many would-be dental patients are intent on postponing appointments until CDCP coverage kicks in. While we urge people not delay dental treatment, the harsh reality is that some cannot afford care without the financial assistance the CDCP promises. In the interim, dentists may begin to provide treatments they have not previously felt the need to use, such as silver diamine fluoride (which, in Canada, is known under the trademarked brand name Advantage Arrest).

Silver diamine fluoride, or SDF, is an inexpensive topical solution. It is basic in nature, and consists of 25% silver fluoride, 8% ammonium fluoride, 5% fluoride, and 62% water. It is used to treat and prevent dental caries and relieve dentin hypersensitivity.

The application of SDF is a simple, non-invasive procedure that involves hard and soft tissue isolation with gauze and cotton rolls, exposing only the area to be treated. This area is air dried, and then SDF is applied with a micro-brush. When SDF is applied to a carious lesion, the silver ions act directly against the bacteria found in these lesions, breaking membranes, denaturing proteins, and inhibiting DNA replication. In addition to its antimicrobial properties, the silver component of SDF also forms a protective layer that increases tooth resistance to acid dissolution. The fluoride ions promote remineralization, increasing mineral density and hardness and decreasing lesion depth.

As a treatment modality for dental sensitivity, topical application of SDF results in the development of a squamous layer on the exposed dentin, partially plugging dentinal tubules and forming a protective layer.

Indications for use

In most cases, SDF should not be considered a replacement for definitive surgical management for carious lesions but, rather, an adjunct for arresting caries in both primary and permanent teeth.

The treatment of carious lesions with SDF is recommended in the following cases:

• Patients who are at a high risk of developing dental decay, including those suffering from xerostomia or severe early childhood decay
• Patients who cannot tolerate standard treatment for medical or psychological reasons, including uncooperative children or frail, elderly people
• Patients with multiple carious lesions requiring more than one visit, in which lesions become symptomatic prior to treatment completion
• Patients who present with carious lesions that are difficult to treat, such as recurrent decay present at a crown margin or root caries found in a furcation
• Patients with limited (or no) access to dental care
• Patients who present with active cavitated carious lesions with no clinical or radiographic signs of pulp involvement

When using SDF, precautions should be taken, as this solution will stain most oxidizable surfaces black. Skin and soft tissue discolouration can occur within minutes to hours after contact. This side effect is temporary, as natural tissue exfoliation will restore pigmentation in two to 14 days. The use of SDF is contraindicated in patients with an allergy to silver and those with exposed pulp, as well as those with any significant desquamative gingivitis or mucositis. Additionally, women who are pregnant or breastfeeding should avoid treatment with SDF. 

Application of SDF

Before treating patients with SDF, it is highly recommended that written informed consent be obtained by either the patient or guardian. Adverse effects (with pictures) should be thoroughly discussed, including the need for re-application and its limits as a restorative treatment replacement.

Once informed consent is acquired, the following steps should be used in the application of SDF:

• Protect yourself, your staff, and the patient
• Patient should wear a plastic drape and safety glasses
• Minimize contact with gingiva and mucous membranes by:
  • Isolating the tongue and cheek from affected teeth
  • Applying petroleum jelly to gingiva near affected areas (optional)
• Remove gross debris to allow for better SDF contact with the lesion
  • Caries removal is not necessary
• Dry affected tooth surface(s) with air syringe
  • Use cotton rolls/gauze/pellets if air syringe is not available
• Place one drop of SDF in a glass or plastic dappen dish (NOT metal)
• Dip micro-brush (comes with kit) into the SDF
• Remove any excess on the side of the dappen dish
• Apply directly onto ONLY the affected tooth surface(s)
• Keep area dry and allow to absorb for one minute
• If there is any excess, remove with a cotton roll, gauze or pellet
  • Avoid air-water spray or compressed air
• Try to keep area isolated for up to three minutes
• Place fluoride varnish (recommended, but optional)
• Dispose of any supplies which have been in contact with SDF into a plastic waste bag and seal to prevent staining
• Recall the patient at two to four weeks, as it may be necessary to reapply SDF monthly to annually until the cavity is restored or arrested
• The effectiveness of caries lesion arrest decreases over time
• Frequency of application after baseline caries arrest has been suggested at three-month follow up, and then semi-annual recall visits over two years

The code that best describes this service can already be found in the NSDA Suggested Fee Guide under Preventive Services. This treatment should be coded as follows:

• Topical application to hard tissue lesion(s) of an antimicrobial or remineralization agent
• 13601: One unit of time + E
• 13602: Two units + E
• 13609: Each additional unit over two + E