How and why to place silver diamine fluoride interproximally

Nov. 7, 2022
Have you ever tried to arrest caries by placing SDF interproximally? This video from Hygiene Edge walks you through the technique.

“Let’s put a watch interproximally on the incipient caries on the mesial of 3.” Maybe you have also heard this treatment plan after a dentist reviews the radiographs and puts a “watch” on an interproximal incipient lesion. In the past, my follow-up would have been reviewing interproximal care for the area and placing a fluoride varnish treatment, then crossing my fingers that it would be enough.

Now, in addition to home care and varnish, we can arrest the caries with silver diamine fluoride (SDF). But how do you get the SDF placed interproximally? Placing it on an area you can see directly is easy, but interproximally you have to use a slightly different technique as you are going in blindly and interproximal caries between a contact is so hard to access. To do this:

  1. Place a spongy floss (like Super Floss) interproximally.
  2. Leave a section of the spongy part to the buccal or lingual side. 
  3. With a micro brush soak the SDF on the spongy part, the length of the interproximal surface. 
  4. Pull that spongy section, full of SDF, interproximally to absorb into the lesion. 

To get patients to accept the procedure, I like to use the phrase “the research shows.” Patients feel more assured that they’re making good decisions when they are evidence-based. For example, I say, “Research shows that silver diamine fluoride helps remineralize enamel and dentin1 and reduces cariogenic bacteria.”2 I also mention that in 2018, the American Dental Association Center for Evidence-Based Dentistry conducted a systematic review and network meta-analysis3 which suggests that “clinicians could also use biannual application of 38% SDF solution to arrest advanced cavitated lesions on coronal surfaces of permanent teeth.”4

More from Hygiene Edge:

Avoid tears and fears when probing

Taking x-rays on patients with mandibular tori

Silver diamine fluoride will cause permanent black staining to carious lesions; luckily it is not visible interproximally, so patients are more willing. It also can leave temporary staining to soft tissues, so create an office policy on gaining informed consent for the treatment. Part of that consent should include that future treatments may be needed as well. 

The hygiene department's focus is prevention, so offering this as a service to patients can help prevent caries as well as increase production. Have a team meeting and discuss if it's right for your practice and how to implement it. Note that at this time, silver diamine fluoride is only approved by the FDA to treat hypersensitivity, which is also another added benefit for patients with this condition. 

Hygiene Edge was created from three dental hygiene educators who love both dentistry and education. With over 40 years of experience both in the education space and the dental field, Melia Lewis, Jessica Atkinson, and Shelley Brown love sharing their knowledge through helpful, short videos online, speaking, and working with amazing companies. You can find more information at Hygiene Edge, on YouTube (, and Instagram (@hygieneedge). Have a question or a tricky area? Let us know! We’d love to help.


1. Mei ML, Ito L, Cao Y, et al. Inhibitory effect of silver diamine fluoride on dentine demineralisation and collagen degradation. J Dent 2013;41(9):809–17.

2. Mei ML, Li QL, Chu CH, et al. Antibacterial effects of silver diamine fluoride on multi-species cariogenic biofilm on caries. Ann Clin Microbiol Antimicrob 2013; 12:4.

3. Urquhart O, Tampi MP, Pilcher L, Slayton RL, Araujo MWB, Fontana M, Guzmán-Armstrong S, Nascimento MM, Nový BB, et al. Nonrestorative treatments for caries: systematic review and network meta-analysis. J Dent Res. 2019 Jan;98(1):14-26. doi: 10.1177/0022034518800014.

4. Silver diamine fluoride. American Dental Association.