Dark Lines on Teeth: Stain or Something Else?
A dark line can appear in a tooth groove, near a filling, or beside the gum. Its color alone cannot show whether it is harmless staining, decay, or a restoration problem. Scraping at it or immediately applying whitening products may miss the reason it developed.
Locate and describe the change
Tell the dentist whether the line is new, whether food catches nearby, and whether the tooth is sensitive. An examination can evaluate the surface and the surrounding tissues. Imaging may be recommended when it would help assess areas that are not directly visible.
Match treatment to the finding
Some surface stains can be addressed during professional cleaning. Other changes require a different approach, and whitening will not repair a cavity or a leaking restoration. Avoid making assumptions based on an online photograph of someone else’s tooth. Teeth can share a similar appearance while having different underlying conditions. A useful first step is identifying the exact location and asking what evidence supports the diagnosis before deciding whether a cosmetic treatment is appropriate.