Tooth decay below gum line
Decay below the gum line can affect exposed root dentine and may need cleaning, a filling, or treatment of the tooth pulp.
The short answer
Tooth decay can develop below the gum line when root dentine is exposed or when decay extends beneath the visible crown. Because this area is difficult to see and clean, a dentist may need to move the gum aside, take an X-ray, and remove the decayed tissue before restoring the tooth.
What is the direct answer?
What does this question mean?
Cementum covering a root is thinner and softer than enamel, so exposed root surfaces can be vulnerable to bacterial acids. Gum recession, a deep cavity, a leaking filling, or plaque trapped under the gum can place the lesion out of sight.
What can you do next?
Brush gently at the gum margin, clean between teeth, and use fluoride toothpaste. Do not delay an examination because the area is hard to see or because pain is mild; early decay may have few symptoms.
When should you seek dental care?
Arrange a dental examination for sensitivity, food trapping, bleeding near one tooth, a rough edge, or a dark area at the gum. Severe pain, swelling, fever, or a bad taste can signal deeper infection.
What should you ask the dentist?
Ask whether the lesion is on the root or crown, how deep it is, and whether a filling, gum procedure, root canal treatment, or extraction is required.
Frequently asked questions
Can a cavity below the gum be filled?
Often it can be restored, but the choice depends on depth, access, remaining tooth structure, and pulp involvement.
Can root decay be reversed?
Early mineral loss may be managed with fluoride and plaque control, but a cavitated lesion needs clinical treatment.