Back gum inflammation
Inflammation behind the back teeth often comes from plaque, a partly erupted wisdom tooth, or an infection that needs examination.
The short answer
Inflammation behind a back tooth is commonly caused by plaque-related gingivitis, food trapped around a wisdom tooth, or a dental infection.
What is the direct answer?
What does this question mean?
The area behind the last molar may include the gum over or beside a wisdom tooth, the cheek-side gum, and the pocket where the tooth meets the gum. Plaque can inflame the gingival margin, while a partially erupted tooth can create a flap that collects bacteria and debris.
What can you do next?
Gently brush the back molar and gum with a soft toothbrush, clean between teeth, and rinse with warm salt water if it is comfortable. Do not cut the gum, place aspirin on it, or force objects under a gum flap; a dentist may irrigate the area, remove plaque or trapped debris, treat decay, or plan wisdom-tooth care.
When should you seek dental care?
Arrange dental care if swelling, bleeding, or tenderness persists, recurs, or is associated with a bad taste or difficulty chewing. Seek urgent care for facial swelling, fever, trouble swallowing or breathing, or difficulty opening the mouth, because infection can spread beyond the gum.
What should you ask the dentist?
Ask whether the inflammation is from gingivitis, a wisdom-tooth pocket, decay, or an abscess, and whether an examination or dental X-ray is needed. Ask which cleaning, filling, drainage, extraction, or home-care step addresses the cause and what warning signs should prompt urgent review.
Frequently asked questions
Can a wisdom tooth cause swelling behind the last molar?
Yes. A partly erupted wisdom tooth can leave a gum flap where bacteria and food collect, causing local inflammation.
Can I treat the cause with mouthwash alone?
Mouthwash may reduce irritation temporarily, but it cannot remove decay, a trapped tooth, or an abscess.