It turned the spot black. Is that normal?
The short answer
Yes. The black is expected, and it's usually a sign SDF is working. It darkens decayed tooth as it hardens and stops the cavity. The stain on the cavity is permanent, but healthy parts of the tooth don't change color. Stains on skin or gums fade within a few days.
What to expect
- The cavity turns dark over the next day or so, from brown to black.
- Healthy enamel stays its normal color. Only the decayed area darkens.
- Skin or gum stains look like a henna tattoo and fade in a few days.
- Stains on clothes, counters, or sinks may be permanent. Rinse spills quickly.
Can the black be covered?
Often, yes. A tooth-colored filling can be placed over the treated area later, which hides most of the dark color. See Will the tooth need a filling later? On baby teeth, the stain goes away when the tooth falls out.
Signs it's working, and signs it isn't
A treated cavity should feel hard and look dark at the follow-up visit. Dark color alone doesn't prove it worked; the spot also needs to be hard when your dentist checks it. If it's still soft or light-colored, your dentist may reapply it. Get seen if the tooth starts to ache, keeps hurting after hot or cold, or the gum near it swells. That can mean the decay reached the nerve.
Questions to ask
- When should we check whether it worked?
- Can a filling cover the dark spot later?
- When should it be reapplied?
- Before we schedule, can I get my cost in writing? (A predetermination if I'm using insurance, or a good faith estimate if I'm paying myself.)
When a second opinion makes sense
Not usually needed for the stain itself. The stain is supposed to be explained before treatment. If a front tooth was treated and you weren't told it would turn black, it's fair to ask the office about it.