Posted in Web Canker Sores: Causes, Symptoms, Treatments, and Remedies January 28, 2021 Canker Sore Treatment. Pain from a canker sore tends to get better in a few days, and the sores usually heal without treatment in about a week or two. Treatment for large, long-lasting, or … https://www.webmd.com/oral-health/guide/canker-sores