A dental abscess typically looks like a swollen, dark-colored bump on your gums, similar to a boil or pimple. It’s usually darker red than the surrounding gum tissue and may have a visible white or yellowish center where pus has collected near the surface. The exact appearance depends on the type of abscess, how long it’s been developing, and where in your mouth it’s located.
The Two Main Types and Where They Appear
Dental abscesses fall into two categories based on their origin, and each one shows up in a slightly different spot.
A periapical abscess starts at the tip of a tooth’s root, usually because decay or a crack has allowed bacteria deep into the tooth. You may not see anything on your gums at first because the infection is buried in bone. As it grows, it can push through the bone and “point” on either the cheek side or tongue side of your gums, appearing as a small, red, raised swelling. Sometimes it even pushes outward through the skin of your face or jaw, creating visible redness and puffiness on the outside.
A periodontal abscess starts in the gum tissue itself, typically in the pocket between a tooth and the gum. This type is easier to spot early. It looks like a shiny, swollen bump right along the gumline, darker than the tissue around it. It often feels soft or spongy to the touch because it’s filled with pus.
What a Gum Boil Looks Like
One of the most recognizable signs of a dental abscess is a gum boil, clinically called a parulis. This is a pus-filled, red, raised bump that forms on the gum surface when infection from a deeper abscess creates a drainage channel up through the bone. It looks strikingly like a pimple, often with a white or yellow head. Some people notice it before they feel any significant pain, since the drainage tract actually relieves some of the pressure building up inside.
If you press gently near a gum boil, you may see pus seep out through a tiny opening at its center. The discharge is usually thick, whitish-yellow, and has a foul taste. A gum boil can shrink and seem to disappear when it drains, then refill and reappear days or weeks later. This cycle of swelling and draining is a hallmark of a chronic abscess that hasn’t been treated at the source.
How It Changes Over Time
In its earliest stage, an abscess may just look like a slightly swollen, tender area of gum that’s redder than usual. There might be no visible bump at all, just a dull ache in the tooth or jaw.
As infection builds, the swelling becomes more defined and the color deepens. Pus accumulates, and you may notice the bump developing a yellowish center. The surrounding gum tissue can look puffy and glazed. At this stage, many people also notice persistent bad breath or a sour, metallic taste from the infection leaking into their mouth.
Chronic abscesses that have been present for weeks or months sometimes form a permanent drainage tract, a small tunnel from the infection site to the gum surface. This can look like a persistent dimple or small nodule on the gum, sometimes with a tiny visible opening. Pressing along the gum near this spot can push pus out through the opening. In rare cases, the infection erodes through bone and drains through the skin of the face or neck instead, appearing as a dimple, nodule, or draining sore on the chin, cheek, or jawline.
How to Tell It Apart From a Canker Sore
Canker sores and abscesses can both create painful bumps in your mouth, but they look quite different. A canker sore is a shallow, flat ulcer that’s white or gray in the center with a clean red border. It typically appears on soft tissue like the inside of your lips, your cheeks, or under your tongue. It hurts when touched but doesn’t produce pus, doesn’t swell outward from the gum, and usually heals on its own within one to two weeks.
An abscess, by contrast, is a raised, rounded bump that’s attached to the gumline near a tooth. It’s filled with fluid, often darker in color, and frequently associated with a specific tooth that’s also painful to bite on or sensitive to hot and cold. If you’re unsure, the location is the biggest clue: abscesses sit on the gums near teeth, while canker sores appear on the movable soft tissue of the mouth.
Swelling Beyond the Gums
When an abscess spreads beyond its original site, the visible signs change dramatically. You may notice swelling in your cheek, under your jaw, or along your neck. The skin over the swollen area can look tight, shiny, and flushed. In some cases, one side of your face becomes noticeably larger than the other. The swelling feels firm and warm to the touch and is usually quite painful.
Facial swelling paired with a fever means the infection has moved beyond the tooth and into surrounding tissues. If swelling reaches your throat or the floor of your mouth (the area under your tongue), it can begin to affect your ability to swallow or breathe. Difficulty breathing, difficulty swallowing, or a fever with facial swelling are signs to go to an emergency room, not wait for a dental appointment.
What Treatment Looks Like
The American Dental Association recommends treating dental abscesses by addressing the source of infection directly rather than simply prescribing antibiotics. For most people, that means one of a few procedures: draining the abscess through a small incision in the gum, performing a root canal to clean out the infected tooth, or extracting the tooth if it can’t be saved. Draining an abscess provides almost immediate pain relief because it releases the built-up pressure.
Antibiotics are reserved for cases where the infection has spread beyond the local area, indicated by fever, general fatigue, or spreading facial swelling. A localized abscess, one that’s contained to a bump on the gum near a single tooth, typically doesn’t need antibiotics at all if the dentist can drain it and treat the tooth.
After drainage or a root canal, the swelling and redness usually begin to improve within a day or two. The gum boil or bump shrinks as the infection clears, though mild tenderness in the area can linger for about a week. Without treatment, an abscess won’t resolve on its own. Even if it drains and the pain temporarily fades, the underlying infection remains and will continue cycling between quiet periods and flare-ups, gradually causing more damage to the surrounding bone and tissue.