A canker sore (aphthous ulcer) is a small, shallow lesion that forms on the soft tissues inside the mouth, such as the tongue, inner cheeks, or gums. These ulcers typically appear as round or oval lesions with a white or yellowish center and a red, inflamed border. Canker sores are common and can make speaking and eating uncomfortable. Generally, a canker sore is not a reason to cancel a scheduled dental appointment, though the decision depends on the procedure and the severity of the sore.
Identifying the Difference Between Canker Sores and Cold Sores
Confusion often arises between canker sores and cold sores, but a significant difference exists, particularly regarding contagiousness. Canker sores occur exclusively inside the mouth and are not caused by a virus, making them non-contagious. They are theorized to be triggered by factors like minor tissue injury, stress, acidic foods, or nutritional deficiencies. Cold sores, conversely, are highly contagious and are caused by the herpes simplex virus (HSV-1), typically appearing outside the mouth on or around the lips. Since canker sores pose no infection risk, rescheduling is necessary only for an active cold sore outbreak.
How the Sore Affects Your Dental Appointment
The presence of an aphthous ulcer makes the dental visit more about patient comfort than medical risk. Routine appointments, such as simple check-ups, X-rays, or light cleanings, are usually manageable with a small canker sore. Dental professionals can easily work around a mild sore and may apply a topical anesthetic beforehand to minimize discomfort.
However, procedures requiring extensive cheek retraction or prolonged suction near the ulcer may need consideration. More invasive treatments, including deep cleanings, fillings, or crown preparation, can irritate a sore, potentially prolonging its healing time. If the canker sore is large, severely painful, or located directly in the area the dentist needs to access, the patient should call the office ahead of time. This allows the dental team to assess the situation and advise whether to proceed or reschedule for the patient’s comfort.
Relief Measures Available at the Dentist
A dental professional can offer specific treatments to help manage the pain and accelerate the healing process. One option is the application of topical corticosteroid ointments, which work to reduce the inflammation and pain associated with the ulcer. These medications can provide more effective relief than over-the-counter products.
Another available in-office treatment is the use of prescription mouth rinses, such as those containing dexamethasone or chlorhexidine. Dexamethasone is a steroid that reduces inflammation, while chlorhexidine is an antiseptic that can help prevent secondary infection. For rapid relief, some dentists offer low-level laser therapy (LLLT), which can stimulate cellular repair and often provides immediate pain reduction after a single short session.