Peroxide-based products are commonly used in dental care for teeth whitening. This article explores how peroxide works to brighten smiles and its effects on dental tissues.
Understanding Peroxide and Dental Whitening
Peroxide is the active ingredient in many dental whitening products, with hydrogen peroxide and carbamide peroxide being the most common forms. Hydrogen peroxide acts as a strong oxidizing agent. Carbamide peroxide breaks down into hydrogen peroxide and urea in the mouth, delivering it to the tooth surface.
The whitening process begins as peroxides break down, releasing reactive oxygen molecules. These oxygen radicals penetrate the enamel and reach the underlying dentin. Inside, they chemically alter dark color pigments, known as chromogens, by breaking down their bonds into smaller, less pigmented components. This reduces stain visibility, resulting in a whiter appearance.
The effectiveness of this process is influenced by the concentration of peroxide, the duration of treatment, and the tooth enamel’s permeability. Products are typically formulated to maintain a mildly acidic to neutral pH, which helps stabilize the peroxide and allows it to penetrate the enamel effectively. Some professional treatments may also use light or lasers to accelerate the breakdown of peroxide, speeding up the whitening process.
Impact on Dental Tissues and Oral Health
Peroxide’s primary effect on dental tissues is the removal of stains and the brightening of tooth color. The oxidation process breaks down the molecules responsible for discoloration, leading to a lighter tooth shade. This addresses both superficial extrinsic stains, such as those from coffee, and deeper intrinsic stains.
Peroxide use can lead to temporary side effects, such as tooth sensitivity. This often occurs because peroxide molecules can pass through the enamel and dentin, potentially causing temporary inflammation in the pulp, the innermost part of the tooth. Another contributing factor is the temporary dislodging of “smear plugs” in dentinal tubules, tiny channels connecting the outside of the tooth to the nerve. This exposure can make the tubules sensitive to external stimuli.
Gum irritation is a common side effect, which typically manifests as redness, inflammation, or a stinging sensation. This irritation occurs when whitening gel contacts soft mouth tissues, especially with ill-fitting trays or improper application. Peroxide agents can cause a chemical burn to gingival tissues, which is usually temporary and resolves once treatment stops. While low concentrations of hydrogen or carbamide peroxide do not cause significant damage to enamel and dentin, long-term daily use can potentially weaken tooth structure and increase susceptibility to erosion.
Safe Practices for Peroxide Use
To ensure safe and effective peroxide use, it is important to follow product instructions carefully and consider professional guidance. Over-the-counter products typically contain hydrogen peroxide concentrations up to 10%, while professional dental treatments can use concentrations as high as 40%. Higher concentrations often achieve results more quickly, potentially reducing the overall exposure time, which can be beneficial in minimizing side effects.
Before starting any whitening regimen, consulting a dentist is recommended. A dentist can assess your oral health, determine if whitening is suitable for you, and identify any underlying dental issues like cavities, gum disease, or existing dental work (crowns, fillings) that might be affected by the whitening process. Whitening agents do not change the color of dental restorations. For at-home kits, apply the gel or strips carefully to ensure they only cover the teeth and do not touch the gums, which helps prevent irritation.
If sensitivity or gum irritation occurs, it is advisable to stop the treatment. Mild gum irritation usually resolves within a few days, and rinsing with saltwater can help alleviate discomfort. Avoiding very hot or cold foods and drinks during and immediately after treatment can also help manage sensitivity. Daily use of hydrogen peroxide can potentially damage teeth and gums, so moderation is advised.