Silver Diamine Fluoride for Root Cavities After 50: Results and the Black-Stain Tradeoff

As gums recede with age, the roots of teeth become exposed and can decay. Dry mouth from medicines makes this worse. Silver diamine fluoride (SDF) is a liquid dentists paint onto cavities to stop them from growing. Here is what the research shows.

How it’s used

A dentist brushes the liquid onto the decayed area. There’s no drilling or numbing. A 2019 evidence update described it as easy, noninvasive, affordable and safe.¹ It kills decay-causing bacteria and helps harden the damaged area.¹

What reviews found

A 2019 review of 11 systematic reviews, including four on root cavities in adults, found SDF:²

• consistently outperformed fluoride varnish, simple fillings and placebo
• helped stop and prevent root cavities in older adults
• caused no serious side effects

The evidence update agreed it’s effective for stopping root decay in older adults and may prevent new cavities.¹ The reviewers noted the studies overlapped heavily and used different methods, so exact numbers vary.²

The tradeoff: black stains

SDF turns the treated decay dark or black.²¹ It’s mainly used when appearance isn’t the top concern, such as on back teeth, along the gumline where it’s less visible, or when a filling isn’t practical.¹

Who might consider it

• People with root cavities who want to avoid drilling
• People who can’t easily sit through longer dental work
• People at high risk of new cavities, such as those with dry mouth

It’s typically part of a broader plan, not a stand-alone fix.¹ Our guides to prescription fluoride toothpaste for root decay and dry mouth at the dentist cover other steps.

Questions for your dentist

1. Which teeth would you treat, and will the stains show when I smile?
2. Will I still need a filling later?
3. How often would it be reapplied?
4. Is it covered by my dental plan?
5. Can a tooth-colored filling go over it if I’m unhappy with the color?

Try: “You found decay on a few roots near my gumline. Would silver diamine fluoride be an option, and where would the dark stains show?”

Is It My Breath? includes a visit script. Use it to list your questions about treatment options, costs and appearance before your dental visit.