Symptoms & conditions

Pimple or bump on gums

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The short answer

A persistent pimple on the gum — often draining pus when pressed — is usually a dental fistula: the body's pressure-relief valve for a tooth infection deeper in the bone. The pimple itself is not the problem; the dying or dead tooth pulp behind it is. Needs X-ray assessment within days.

What's happening

The clinical picture

When a tooth's pulp dies from decay, a crack, or old trauma, bacteria multiply in the root canal and push pressure out through the bone. Rather than causing acute facial swelling, the body often drains the chronic infection through a fistula — a tiny tract running from the root tip through the bone to the gum surface. The pimple is the external opening. It may drain pus intermittently, shrink, and come back. Patients often ignore it because it doesn't usually hurt — which is exactly the problem. The underlying infection is active even when the pimple is quiet.

Warning signs

Contact us the same day if:

  • Pimple that drains pus when pressed
  • Bad taste in the mouth intermittently
  • Pimple that shrinks and returns repeatedly
  • Nearby tooth that is slightly tender or discoloured
  • History of trauma or decay in that area

What we do

Our approach

Periapical X-ray of the teeth in that area to find the dark shadow at a root tip — confirms the fistula's origin. Sometimes we insert a small gutta-percha cone into the fistula and re-X-ray; it traces the tract right to the source tooth. Root canal treatment saves the tooth in most cases; extraction when the tooth is past saving. Antibiotics rarely the answer — they don't reach a dead tooth with no blood supply.

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