Hydrogen peroxide (H2O2) is a chemical compound used as a mild antiseptic. Its formulation is similar to water, but an extra oxygen molecule allows it to act as a powerful oxidizing agent. This property makes it a frequent ingredient in oral hygiene products, including mouthwashes designed to address specific dental concerns.
Oral Health Applications
Hydrogen peroxide functions as an oxidizing agent, releasing oxygen when it contacts enzymes in the mouth. This oxygen release creates an environment where it is difficult for some bacteria to survive, particularly anaerobic bacteria associated with gingivitis and plaque. The bubbling action also helps to mechanically clean areas and remove debris.
This same oxidizing action allows hydrogen peroxide to whiten teeth. It penetrates tooth enamel and breaks down molecules that cause surface stains, leading to a brighter appearance. Its antiseptic properties also make it useful for providing temporary relief from minor mouth irritations, like canker sores, by cleaning the affected area.
Guidelines for Safe Use
For oral use, only use a 3% concentration of hydrogen peroxide, the standard strength sold in most drug stores. Products with higher concentrations, such as food-grade hydrogen peroxide at 35%, are not safe for oral applications and can cause significant harm.
Before using it as a rinse, the 3% solution should be diluted. The standard method is to mix it in a 1:1 ratio with water. This dilution minimizes the harshness of the compound, making it safer for the soft tissues of the mouth.
Once diluted, swish the solution in the mouth for 30 to 60 seconds. After swishing, it is imperative to spit the entire solution out. Under no circumstances should the mixture be swallowed. Hydrogen peroxide rinses are best for short-term use, not as a permanent part of a daily routine unless otherwise directed.
Potential Adverse Effects
Improper or prolonged use of hydrogen peroxide as a mouthwash can lead to soft tissue irritation. This can manifest as a burning sensation, redness, or even temporary bleaching of the gums and other tissues inside the mouth.
Tooth sensitivity is another significant risk. The peroxide can penetrate the enamel and the underlying dentin layer, leading to increased sensitivity to hot and cold temperatures. This is particularly true for individuals who already have thinning enamel or receding gums.
Long-term, frequent use carries the risk of damaging tooth enamel, as the compound can gradually erode this protective outer layer. A rare side effect is black hairy tongue, a temporary condition where the papillae on the tongue elongate and become stained, giving it a dark, furry appearance.
Swallowing the solution poses serious health risks. Ingesting hydrogen peroxide can cause severe irritation to the throat and digestive tract, leading to stomach upset, vomiting, and abdominal pain. Always spit out the rinse completely after use.