
Let’s play a little game. Imagine your fluoride varnish brush could talk. You pick it up, ready to slather it across the facial and lingual surfaces of your patient’s teeth, and it whispers:
Psst… I’m only here for sensitivity.”
Excuse me? We both know that’s not the real reason you’re using it. You’re using it to prevent cavities. So why the double life?
Not-So-Secret Agents: Fluoride Varnish & SDF
If you work in dentistry, you know there are two magical fluids we love using to fight decay without breaking out the drill: fluoride varnish and silver diamine fluoride (SDF).
But here’s the kicker: neither is FDA-approved for the thing we all use them for – you know, the actual preventing or arresting of cavities. They’ve got their little badges that say, “I’m here to reduce sensitivity,” and that’s it. It’s like hiring a security guard to scare off pigeons and they stop a bank robbery instead. Not exactly their “official” job, but they’re killing it nonetheless.
So… Are We Doing Dentistry Wrong?
Not at all. This is what the grown-up version of medicine looks like: off-label use. That means we, as clinicians, are allowed to use products in ways that aren’t specifically written on the packaging, as long as there’s good science behind it and we’re not just winging it with snake oil and hope.
Fluoride varnish has been used off-label for decades to prevent caries. Every major dental organization (ADA, AAPD, CDC) backs it. It’s reimbursed by Medicaid for that purpose in many states. Even pediatricians – outside of a dental setting – are authorized to apply fluoride to children’s teeth under certain medical guidelines. But the label? Still just for hypersensitivity.
Silver diamine fluoride (SDF) – same deal. It got FDA clearance in 2014 for sensitivity. But its real superpower is stopping decay in its tracks. You paint it on a mushy lesion and – bam! – it freezes like Elsa just sang at it. Black, hard, ugly-but-healthy decay. Not glamorous, but incredibly effective, especially for kiddos, elders, and patients who can’t tolerate traditional treatment.
Why Not Just Change the Label?
Here’s the not-so-fun part: getting a new FDA indication is expensive. Like, “we could build a small dental school for this money” expensive. Most of the companies that make fluoride varnish and SDF are not Big Pharma. They’re more like Little-To-Medium-Sized Dental Supply. If their product is already being widely used and endorsed for the off-label thing? Why spend millions for a gold sticker that says “Approved”?
Also, if it ain’t broke (and no one’s getting sued), they’re not fixing it.
The Ethics and the Eyebrow Raises
Now, I’m not saying you shouldn’t know what’s on-label and what’s not. It matters. Patients deserve transparency, and we owe it to them to explain why their kid’s teeth are turning black (SDF, looking at you) or why we’re applying fluoride varnish after a cleaning even though they don’t have “sensitive teeth.”
The next time you brush on that fluoride varnish or dab a bit of SDF, give a little nod to its secret identity. Off-label? Definitely. Totally legal? You bet. Cavity-fighting? That’s the plot twist they didn’t print on the package.
TL;DR for Your Patients (and Curious Colleagues)
- Fluoride varnish: FDA says it’s for sensitivity. We use it for cavities.
- SDF: FDA says it’s for sensitivity. We use it to stop decay cold.
- Both are off-label for caries, but not off-limits.
- Science is on our side.
- No one’s getting arrested. (Except maybe the cavities.)
What’s your take? Are we stretching the label, or just catching up to the science? Will this be one more talking point for those on the anti-fluoride side? Share your thoughts in the comments.

References
- FDA 510(k) Summary for Advantage Arrest (SDF): FDA Clearance Database
- ADA Clinical Practice Guidelines for SDF: ADA.org
- ADA Topical Fluoride Guidelines: ADA.org
- CDC’s Take on Fluoride Varnish: CDC.gov
- AAPD Policy on Fluoride Therapy: AAPD.org