Canker sores are common mouth ulcers, appearing as small, painful lesions inside the mouth. They typically feature a white or yellowish center surrounded by a bright red, inflamed border. Unlike cold sores, canker sores are not contagious and are not caused by the herpes virus. While some traditional beliefs suggest applying salt directly to these sores, understanding its interaction with oral tissues is important.
How Salt Interacts with Canker Sores
Applying salt directly to a canker sore initiates osmosis. Salt creates a hypertonic environment, meaning it has a higher concentration of solutes than the cells of the oral tissue. This causes water to be drawn out of the sore’s cells and surrounding tissues.
This osmotic action temporarily dehydrates the area. However, this process also leads to an intense stinging sensation. Exposed nerve endings in the sore are highly sensitive, and the salt can disrupt their electrical balance, triggering significant pain signals.
Why Applying Salt is Not Recommended
Directly applying salt to a canker sore, rather than using a diluted salt water rinse, is generally not recommended due to the severe discomfort it causes. The intense stinging pain results from salt drawing moisture out of delicate oral cells and irritating exposed nerve endings. This discomfort can be counterproductive to healing.
Rubbing salt into the ulcer can traumatize sensitive oral tissue, potentially causing more damage. While salt has some antiseptic properties, the harshness of direct application can hinder the natural healing process by irritating the wound further. The acute pain and potential for tissue damage outweigh any perceived benefits of direct salt application.
Effective Approaches for Canker Sore Relief
Several evidence-based approaches can provide relief and promote the healing of canker sores. Over-the-counter topical anesthetic gels (e.g., benzocaine, lidocaine) can numb the affected area, offering temporary pain relief. Protective pastes can form a barrier over the sore, shielding it from irritation during eating or speaking.
Rinsing the mouth with a warm saline solution (1 teaspoon of salt in 1/2 cup of warm water) or a baking soda rinse can soothe the sore and create an environment conducive to healing, without the harshness of direct salt application. Avoiding irritants such as acidic, spicy, or abrasive foods is beneficial, as these can exacerbate pain and delay recovery. Maintaining good oral hygiene, using a soft-bristled toothbrush, and reducing stress may help prevent recurrence. If canker sores are unusually large, persist for more than two weeks, recur frequently, or are accompanied by a high fever, consulting a healthcare provider is advisable.