close-up of a young woman holding her cheek in pain
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The most common problems from rinsing with hydrogen peroxide involve increased sensitivity to hot or cold foods. In some cases, you might also experience stinging sensations, mouth sores and other forms of irritation inside your mouth. While these problems are temporary for most people, it’s important to check the strength of the hydrogen peroxide and to limit the amount of time in which the product is used. Ask your doctor before rinsing with hydrogen peroxide or a commercial peroxide product.


Some people use hydrogen peroxide, in either homemade or professional preparations, to clean and whiten teeth. Hydrogen peroxide has bleaching power, which makes it useful in everything from tooth-whitening kits to hair dyes and cleaning products. It also possesses broad-spectrum antimicrobial properties. For dental hygiene purposes, this bacteria-killing characteristic means hydrogen peroxide provides protection against germs that cause gum and tooth disease, as well as those contributing to bad breath.

Mouth Irritation

Depending on the concentration of the hydrogen peroxide used, dental formulas might cause blisters and sores inside the mouth. In milder solutions, hydrogen peroxide might simply provoke a stinging sensation just after rinsing. New York University’s Langone Medical Center notes that some people who use whitening treatments erroneously attribute irritation to the hydrogen peroxide. But if the kit involves a mouth guard or tray, it might be this device, rather than hydrogen peroxide, causing the irritation. Rinsing with hydrogen peroxide, rather than applying it with a dental tray, might lessen your risk of mouth sores or irritation.


Hydrogen peroxide works well as a bleaching agent because it penetrates the enamel more deeply, reaching stains even at the underlying dentin layer. Unfortunately, this deep penetration increases the risk of temporary sensitivity to temperature and to touch. As many as two-thirds of people using hydrogen peroxide dental products develop temporary sensitivity to hot or cold drinks. According to the journal “Medical Hypotheses,” sensitivity to any kind of touch or pressure might arise even without the stimulation of cold or hot drinks, a phenomenon known as bleaching sensitivity. Both types of sensitivity are associated with using hydrogen peroxide on teeth, and tend to subside after treatment is discontinued.


You might find that using hydrogen peroxide at a lower concentration reduces the pain you feel after rinsing with the product. Dentist-prepared whitening kits might use a 35 percent-strength peroxide formula, while commercial whitening toothpastes are as low as 6 percent. If you prepare your own whitening and cleaning rinse, consider buying an even milder concentration. Drugstore bottles come in 1 to 6 percent strengths. Dilute hydrogen peroxide in water until you reach a ratio that eliminates pain.

Aggravating Factors

Several factors might determine whether a person feels pain after rinsing with hydrogen peroxide. Long-term use of a homemade or store-bought peroxide treatment might increase tooth sensitivity through ongoing penetration into the tooth. Ultimately, long-tern use might cause penetration through the enamel and dentin layers, into the dental nerve pulp. In addition, people with existing gum tissue damage are more prone to sensitivity to peroxide, as are people who regularly drink alcohol or use tobacco products. Always ask your dentist if your medical history or current habits put you at risk for mouth pain after rinsing with hydrogen peroxide.