A canker sore is a common type of small, painful lesion that develops inside the mouth. These non-contagious sores appear as round or oval lesions with a white or yellowish center and a distinct red border. They are not caused by a virus and typically form on the soft tissues of the mouth, such as the inside of the cheeks, the tongue, or the floor of the mouth. These ulcers often heal on their own within one to two weeks.
Oral Trauma and Aphthous Ulcers After Surgery
The appearance of a canker sore is often a direct result of localized physical trauma following dental surgery. Dental surgery involves significant manipulation of the surrounding soft tissues, which can lead to minor injury and irritation. This injury, whether caused by surgical instruments, sutures, or the rubbing of the cheek against a newly exposed area, is a trigger for aphthous ulcers.
The theory behind this is that the physical disruption to the mucosal lining initiates an immune response, causing the body’s immune cells to attack the cells of the mouth lining. This process results in the formation of the painful, superficial ulcer. Even aggressive brushing or irritation from a sharp bone edge post-operation can be enough localized trauma to trigger a sore.
Beyond the direct physical injury, the overall process of wisdom tooth removal can contribute to the development of these lesions. Emotional stress and anxiety related to the procedure are recognized antagonists that can weaken the immune system, making a person more prone to developing canker sores. Hormonal fluctuations and nutritional deficiencies, such as low levels of iron or B-12, can also be contributing factors in the post-operative period.
Distinguishing Canker Sores from Post-Extraction Complications
A canker sore has distinct characteristics that differentiate it from more serious post-extraction complications. A minor aphthous ulcer is typically small, often less than 10 millimeters in diameter, and presents as a clearly defined, superficial lesion with a white or yellow film. The pain tends to be localized and confined to the lesion itself.
In contrast, a dry socket, or alveolar osteitis, is a condition where the protective blood clot in the extraction site is dislodged or dissolves prematurely, exposing the underlying bone and nerve endings. The primary difference is the nature of the pain, which is typically severe, throbbing, and intense, often radiating out to the ear, temple, or neck. This pain usually begins to worsen significantly around two to four days after the surgery, rather than improving.
An infection in the extraction site presents differently from both a canker sore and a dry socket. Signs of infection include generalized swelling that increases instead of subsiding, a fever, and the presence of pus or discharge from the socket. While a dry socket involves a foul odor or taste, it is not an infection and does not typically cause fever or significant swelling. If you notice pain that is worsening, systemic symptoms like a fever, or visible exposed bone, immediate consultation with a dental professional is necessary.
Strategies for Pain Relief and Healing
The goal of treatment is to manage the pain and encourage healing. One of the simplest and most effective home remedies is rinsing the mouth with warm salt water, which helps soothe the area and promote tissue recovery. You can also apply a thin paste made from baking soda and water directly onto the ulcer to neutralize acids and protect the surface.
Reducing irritation is a simple but effective strategy, which means temporarily avoiding foods that are acidic, spicy, or sharp, as these can aggravate the open wound. Over-the-counter topical treatments containing local anesthetics, such as benzocaine, can be applied to the sore to temporarily numb the area and provide pain relief, particularly before meals. Specific oral rinses, including those containing hydrogen peroxide, may also be used to reduce bacteria and promote healing.
For sores that are particularly severe, large, or persistent, a dentist may prescribe stronger treatment options. These can include medicated rinses, such as those containing a topical corticosteroid, which helps to reduce inflammation and speed up healing. If a minor aphthous ulcer lasts longer than two weeks, or if it is unusually large, consulting with a dental professional is advised to rule out other possible conditions.