Treating dental decay with Silver Diamine Fluoride
Silver Diamine Fluoride (SDF) is a solution well known to arrest dental cavities. It has had a long history of use. However, its approval for use in Canada is recent. It can be an alternative to traditional drilling/filling of teeth and can even avoid the use of sleep dentistry (general anesthesia) in apprehensive children.
The history of SDF use is interesting. The precursor to silver diamine fluoride is silver nitrate or also called the ‘forgotten remedy.’ In 1891 Stibbens determined that silver was capable of inhibiting cavities as a result of destroying bacteria. A drawback of this pioneering treatment is that it made teeth brittle due to the loss of calcium. Silver nitrate was a popular treatment. However, around 1951, when fluoride dentifrice and local anesthesia came to the market place, silver nitrate use virtually disappeared in North America. In Japan, however, research was still being conducted. In 1969 Professor Mizuho Nishino researched SDF as her Ph.D. project. In 1970 Japan approved its use under the brand name ‘Saforide.’ There have been over 2 million bottles of it sold with zero adverse outcomes.
SDF combines the antimicrobial power of silver with the remineralization power of fluoride. The composition is 25% silver (antimicrobial agent), 8% ammonia (solvent), 5% fluoride (remineralisation agent). SDF is the synergy of silver and fluoride, as they are better in combination than they are individual. It arrests and prevents dental cavities, as well as decreases dental hypersensitivity (tooth sensitivity). In 2016 the FDA granted SDF the prestigious ‘breakthrough therapy designation’ for cavities. SDF is the only oral medicine ever to receive this special designation.
Its mechanism of action is:
- Occludes dental tubules (pores in teeth)
- Increases mineral density and hardness
- Destroys bacteria in cavities
SDF is an antimicrobial agent. It accomplishes this by inhibiting tooth plaque biofilm, denaturing proteins, breaking bacteria cell walls, and inhibiting bacteria DNA (genetic material) replication. SDF works well partly because of its ability to penetrate tooth structure. In particular, it can penetrate enamel by 25 microns, and dentin by 200-300 microns.
Not all dentists offer SDF treatment because it was not part of the vast majority of practicing dentist’s education. However, due to the safety and efficacy of the product, its use is increasing. Dr. Hawryluk Jr. feels that SDF stops cavities about 70% of the time on the first application. It’s stopping power increases for those cavities which he can fully access and undergo a second coating of SDF a few weeks later. To assess for cavity arrestation, Dr. Hawryluk will test the hardness of the surface. After a second coating, a filling sometimes is applied over the area. Patients appreciate this conservative approach to dental treatment.
SDF does not replace filling treatment in all instances, and there are some drawbacks. SDF will permanently stain decay and decalcifications. In other words, the arrested tooth decay will not appear white. SDF does not restore form or function. If a tooth is has a deep hole, a dental filling in place of (or in conjunction with) SDF treatment may be indicated to prevent further breakdown of the tooth and improve cleaning around it. Also, filling the tooth can prevent its fracture and food entrapment, which can lead to lesion reactivation. For example, caries arrested in a fissured groove (top part of back teeth) will still be a fissured groove, which is challenging to cleanse. Placing a filling/sealant over the arrested tooth groove is beneficial to cleanability and helps maintain the arrest of the lesion.
There are no eating or drinking requirements after application unless Dr. Hawryluk has applied SDF in conjunction with a professional fluoride application. The color change of the decay will occur over 24 hours. Often we will reevaluate and reapply the solution in 2-4 weeks, with another application six months later. Proper diet, hygiene, daily fluoride use will play a critical role in the success of this treatment. If successful, the affected areas should have a ‘matte black’ or charcoal briquette appearance. In radiographs, the lesion size should appear stable and may even look better due to the formation of ‘secondary dentin. The area should not be tender, and patients may experience a decreased sensitivity to cold.
In some cases, Dr. Hawryluk places an SDF, and ‘glass ionomer dental restoration’ in conjunction. This combination is called a ‘SMART’ restoration or ‘silver modified atraumatic restorative treatment.’ The glass ionomer filling material will restore the shape of the tooth, and further help remineralize the area.
Please indicate on our patient questionnaire if you or your child have a silver allergy. If the SDF comes into contact with inflamed tissue, it may cause a temporary burning sensation due to ammonia. If SDF gets on any of the oral tissues, they too will stain, and it will take about two weeks for a ‘henna-like tattoo’ mark to disappear.
SDF can offer fantastic benefits and avoid invasive dentistry. If you would like to learn more about this beneficial treatment, please contact us to book a consultation.
References: Be SMART: Improve Your Practice with Silver Diamine Fluoride and Glass Ionomer Cement. 2017. Viva Learning.