Swollen Gums Around One Tooth: Causes and Treatment

Noticing a swollen, tender area of gum around a single tooth can be uncomfortable and concerning. Unlike generalised bleeding or inflamed gums that affect several areas of the mouth, localised swelling usually points to a specific cause that your dentist can identify and treat. Understanding what may be behind the swelling can help you decide how urgently you need to seek professional advice.

Common Causes of Swollen Gums Around a Single Tooth

Food Impaction and Plaque Build-Up

One of the most frequent causes of localised gum swelling is food becoming trapped between teeth or under the gumline. When food debris is not removed through brushing and interdental cleaning, bacteria can accumulate and irritate the surrounding gum tissue. Over time, this may lead to a pocket of inflammation that feels swollen and tender to the touch. Areas where teeth are crowded, tilted, or have old restorations with rough edges tend to be particularly prone to food trapping.

Dental Abscess

A dental abscess is a collection of pus caused by a bacterial infection. It can form at the tip of the tooth root (periapical abscess) or in the gum tissue beside the root (periodontal abscess). Abscesses typically cause a noticeable, sometimes painful swelling that may appear as a raised bump on the gum. You might also notice a bad taste in your mouth if the abscess begins to drain. A dental abscess will not resolve on its own and requires professional treatment, which may include drainage, root canal treatment, or in some cases extraction of the affected tooth.

Pericoronitis Around a Wisdom Tooth

If the swelling is at the very back of your mouth, it may be pericoronitis — inflammation of the gum tissue that partially covers a wisdom tooth that has not fully erupted. Food and bacteria can become trapped under this flap of gum, leading to swelling, pain, and sometimes difficulty opening the mouth or swallowing. Pericoronitis is particularly common in younger adults between the ages of 17 and 25, when wisdom teeth are most likely to be erupting.

Localised Gum Disease

While gum disease (periodontal disease) often affects the mouth more broadly, it can sometimes be more advanced around a single tooth. This may happen where plaque and tartar have built up in a particularly deep pocket, or where the shape of the tooth root makes cleaning difficult. Bone loss around one tooth can create a deeper pocket that traps more bacteria, leading to a cycle of worsening inflammation. If left untreated, this may eventually affect the stability of the tooth.

Ill-Fitting Crown or Restoration

A crown, bridge, or filling that does not fit precisely can create a ledge or gap where plaque accumulates. The gum tissue around the restoration may become chronically irritated and swollen. This is sometimes accompanied by a persistent bad taste or mild bleeding when brushing. Your dentist can assess whether the restoration needs to be adjusted, replaced, or whether additional cleaning is needed to settle the inflammation.

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Symptoms to Watch For

While mild gum swelling may not feel alarming, certain accompanying symptoms can suggest a more serious issue that needs prompt attention. These include:

• Persistent or worsening pain that does not respond to over-the-counter painkillers
• Bleeding from the gum when brushing or eating, particularly if it is new or more than usual
• Pus or discharge from the swollen area, which may leave a foul taste in the mouth
• A raised bump or boil on the gum (sometimes called a gum boil or parulis), which often indicates an abscess
• Fever, facial swelling, or difficulty swallowing — these are signs of a spreading infection and should be treated as a dental emergency
• Loose tooth in the affected area, which may suggest advanced bone loss

Home Care: What You Can Do Before Seeing a Dentist

While home care cannot replace professional treatment, it may help manage symptoms and keep the area clean while you wait for an appointment.

• Warm salt water rinses: Dissolve half a teaspoon of table salt in a glass of warm water and rinse gently for 30 seconds, two to three times a day. Salt water can help reduce bacteria and may ease mild inflammation.
• Gentle but thorough brushing: It may be tempting to avoid the sore area, but keeping it clean is important. Use a soft-bristled toothbrush and brush gently around the swollen gum.
• Interdental cleaning: Carefully use interdental brushes or floss around the affected tooth to dislodge any trapped food or debris. If food impaction is the cause, this alone may bring relief.
• Over-the-counter pain relief: Ibuprofen (if suitable for you) can help reduce both pain and inflammation. Paracetamol is an alternative if you cannot take anti-inflammatories. Always follow the dosage instructions on the packet.
• Avoid irritants: Try to avoid very hot or cold foods on the affected side, and steer clear of crunchy or sharp foods that may further irritate the gum.

Professional Treatment Options

Your dentist will examine the area, often with the help of X-rays, to determine the underlying cause. Treatment will depend on the diagnosis:

• Professional cleaning: If plaque and tartar are contributing to the swelling, a thorough scale and polish can remove the irritants and allow the gum to heal.
• Drainage of an abscess: If an abscess is present, your dentist may need to drain the pus and clean the area. This is often followed by a course of antibiotics if the infection is significant.
• Root canal treatment: If the tooth's nerve is infected (periapical abscess), root canal treatment may be needed to save the tooth and clear the infection.
• Antibiotics: These may be prescribed if there are signs of spreading infection, though they are not a substitute for treating the source of the problem. Antibiotics alone will not cure an abscess.
• Adjustment or replacement of restorations: If a poorly fitting crown or filling is the cause, your dentist can adjust or remake it to restore a proper fit.
• Wisdom tooth management: For pericoronitis, treatment may include cleaning under the gum flap, antibiotics if needed, and potentially extraction of the wisdom tooth if episodes are recurrent.

When Is It Urgent?

Swollen Gums Around One Tooth vs General Bleeding Gums

It is worth distinguishing between localised swelling around a single tooth and more widespread gum problems. If your gums bleed regularly across multiple areas when brushing, this is more likely to be a sign of generalised gingivitis or gum disease. You can read more about this in our guide to bleeding gums myths and facts. Localised swelling, by contrast, usually has a specific, identifiable cause that can be targeted with treatment.

Frequently Asked Questions

Why is the gum around one tooth swollen?

Swelling around a single tooth is usually caused by a localised issue such as trapped food or plaque buildup, a dental abscess, pericoronitis around a partially erupted wisdom tooth, or an ill-fitting crown or restoration. A dentist can examine the area and take X-rays to identify the exact cause.

Can swollen gums go down on their own?

Mild swelling caused by temporary irritation, such as a piece of trapped food, may settle within a day or two once the irritant is removed. However, swelling caused by infection, abscess, or gum disease is unlikely to resolve without professional treatment. If the swelling persists for more than two to three days or is getting worse, consult your dentist.