Canker sores, also known as aphthous ulcers, are common, small, shallow lesions that appear inside the mouth. These open sores are typically white or yellowish and are surrounded by a bright red border. They can form on the tongue, gums, inner cheeks, or the roof of the mouth, causing discomfort and sometimes making eating and talking difficult. Canker sores are not contagious and differ from cold sores, which are caused by a virus and usually appear on the lips.
How Peroxide Interacts with Canker Sores
Hydrogen peroxide is often considered for canker sores due to its mild antiseptic properties. When applied to a canker sore, hydrogen peroxide releases oxygen, which creates a foaming action. This process helps to clean the area by removing dead cells and reducing the presence of bacteria, particularly anaerobic bacteria that thrive in low-oxygen environments.
While hydrogen peroxide may help keep the canker sore clean and reduce the bacterial load, its effectiveness in significantly speeding up healing or providing substantial pain relief is not strongly supported by extensive scientific evidence. It is not considered a definitive cure or primary treatment, with dental professionals often recommending its use for its cleansing action.
Safe Application Guidelines
When using hydrogen peroxide for canker sores, proper dilution is necessary to prevent irritation. A common recommendation is to dilute 3% hydrogen peroxide solution with an equal part of water. This diluted mixture can be used as a mouth rinse or applied directly to the sore. For direct application, a cotton swab can be dipped into the diluted solution and gently dabbed onto the canker sore.
Swish or dab the solution for 30 to 60 seconds. The solution should always be spit out after use, as swallowing hydrogen peroxide can cause stomach upset. This application can be repeated three to four times a day. If any irritation or discomfort occurs, reduce the frequency of use or stop altogether.
Potential Adverse Effects
Using hydrogen peroxide can lead to several negative consequences for oral tissues. High concentrations or prolonged exposure can damage oral soft and hard tissues. Potential side effects include irritation, stinging, or burning sensations. Chemical burns to the oral mucosa can occur with undiluted solutions or if a 3% solution is used for more than two minutes.
Hydrogen peroxide can also disrupt the natural balance of bacteria in the mouth, potentially leading to other oral health issues. One notable but rare side effect of prolonged or excessive use is the development of a temporary condition called “black hairy tongue.” Swallowing the solution can cause nausea, vomiting, or digestive issues. Concentrated forms are hazardous and should never be used orally due to the risk of severe internal injury or even death.
Other Approaches for Canker Sore Relief
Several other options can help manage canker sore discomfort and promote healing. Rinsing the mouth with a warm saltwater solution can help dry out the sores and reduce inflammation. Applying milk of magnesia directly to the canker sore may help neutralize acid and act as a protective coating.
Over-the-counter topical gels and creams containing numbing agents like benzocaine or lidocaine can provide temporary pain relief when applied directly to the sore. Oral rinses specifically designed for mouth sores are also available and can help keep the area clean. Avoiding acidic, spicy, or abrasive foods can prevent further irritation and discomfort during the healing process. If canker sores persist for more than two weeks, recur frequently, or are accompanied by symptoms like fever, consulting a healthcare professional is advisable.