Treatment usually isn't necessary for minor canker sores, which tend to clear on their own in a week or two. But large, persistent or unusually painful sores often need medical care. A number of treatment options exist. There are many other topical products for canker sores, including those without active ingredients. Oral steroid medications when severe canker sores don't respond to other treatments. But because of serious side effects, they're usually a last resort. Cautery of the sores... Consult Physician...