A canker sore, medically known as an aphthous ulcer, is a common and painful lesion that develops on the soft tissues inside the mouth, such as the cheeks, tongue, or gums. These shallow sores appear white or yellow with a distinct red border and are not contagious, distinguishing them from cold sores. The discomfort often leads people to seek quick relief through home remedies, with the salt water rinse being a long-standing and frequently recommended traditional treatment.
What Causes Canker Sores
The precise cause of canker sores remains unclear, but they are thought to result from an abnormal immune response triggered by various factors. Common triggers include minor physical injuries, such as accidentally biting the cheek or trauma from harsh brushing or dental work. Stress and anxiety are also strongly associated with the onset of canker sore episodes.
Certain foods, particularly those that are highly acidic or spicy, can irritate the oral lining and trigger an outbreak. Underlying nutritional deficiencies, such as low levels of Vitamin B12, iron, folic acid, or zinc, can also contribute to the development of these ulcers. The use of toothpastes containing the foaming agent sodium lauryl sulfate (SLS) has been suggested as a potential irritant.
How Salt Water Rinses Work
The effectiveness of a salt water rinse is rooted in basic biological principles. Salt, when dissolved in water, creates a hypertonic solution, meaning it has a higher concentration of solutes than the cells in the mouth tissue. This osmotic effect draws excess fluid out of the inflamed tissue, which helps to dry out the area and reduce swelling.
Reducing this localized swelling helps to minimize pressure on nerve endings, providing pain relief. The salt solution also works as a mild, mechanical cleanser that helps remove food debris and irritants from the ulcer’s surface. Additionally, salt temporarily raises the mouth’s pH level, creating an alkaline environment that aids in maintaining a clean environment for healing.
Safe Application and Managing Discomfort
To create an effective rinse, mix about one-half to one teaspoon of common table salt into one cup of warm water. Using warm water, rather than hot, aids in dissolving the salt without causing further inflammation to the sensitive oral mucosa. Swish the solution gently around the mouth for about 15 to 30 seconds, ensuring it makes contact with the sore, before spitting it out.
The initial contact of the salt solution with the open sore will likely cause a sharp, stinging sensation. This temporary discomfort indicates that the drying and cleansing action is taking place. Repeat this rinsing process several times a day, typically two to four times, until the sore begins to heal. Do not swallow the solution, and avoid using a higher concentration of salt, as this can irritate or damage the surrounding healthy tissue.
Alternative Treatments for Healing
Several at-home and over-the-counter treatments are available to manage symptoms and encourage healing. Topical pastes and gels containing ingredients such as benzocaine or fluocinonide can be applied directly to the sore for localized numbing and pain relief. Another common home remedy is a rinse made with baking soda, which helps neutralize acidity and reduce inflammation.
Dabbing milk of magnesia onto the ulcer with a cotton swab can help by coating the sore and neutralizing localized acid, protecting it from irritation. If canker sores are unusually large, occur frequently, or fail to improve after two weeks of home care, consult a dentist or physician. A medical professional can rule out underlying systemic issues and may prescribe stronger rinses or topical steroids for more severe cases.