The most common side effects experienced by people using peroxide-based teeth whitening products are:
Some other less common side effects that are sometimes encountered are: throat irritation, tooth pain, tissue "tingling", and headaches.
No, not everyone will develop side effects when whitening their teeth although experiencing them is very common place. It has been estimated that as many of two-thirds of the people who use peroxide-based teeth whiteners will experience some degree of sensitivity.
It's impossible to know specifically who will develop side effects and who won't. Even when using the same teeth whitening product and identical technique, some people will find they experience no side effects whereas other individuals may experience several. Those people who have one or more of the following characteristics or participate in one or more of the activities listed below are possibly more likely to develop side effects when they whiten their teeth:
The side effects associated with peroxide-based teeth whitening are usually most intense during that time frame (a series of days or weeks) during which the bleaching process is being performed. Typically they resolve quickly after the teeth whitening process has been terminated, sometimes within 24 hours. Usually the side effects a person experiences are mild and do not interfere with their bleaching activities.
Clinical studies suggest that about half of the people who use peroxide-based teeth whitening products will experience some degree of tooth sensitivity as a side effect. Usually this sensitivity is thermal in nature, meaning a person's teeth will react to the temperature changes they are exposed to (such as exposure to hot or cold beverages).
Tooth sensitivity is usually mild and transient. Typically it initiates within the first few days during which the whitening treatment has been begun. For most people the tooth sensitivity they experience does not interfere with their bleaching activities and dissipates after the bleaching process has been terminated.
The precise cause of the tooth sensitivity associated with peroxide teeth whitening products is not fully understood. It is likely related to an inflamed state of the tooth's pulpal tissue (nerve tissue) that has been caused by exposure to the peroxide contained in the whitener. This may explain why whitening products containing a lower concentration of peroxide are typically thought to have less potential for creating side effects than those containing higher concentrations.
Another cause of tooth sensitivity produced by the use of tray-based teeth whitening products can be related to the bleaching tray being used. Ill fitting stock bleaching trays can put pressure on individual teeth.
If this pressure is great enough it can cause a tooth to become sore or even cause it to shift in position.
Clinical studies suggest that up to half of the people who use peroxide-based teeth whitening products will develop some degree of gum irritation as a side effect. Usually this takes the form of a mild to moderate sensitivity that initially appears within two or three days after first using the whitener. It will then typically begin to dissipate. For most people the gum sensitivity they experience does not interfere with their teeth whitening activities.
Clearly the cause of the gum sensitivity associated with peroxide-based teeth whitening products is multifactorial. The concentration of the peroxide that is found in the tooth whitener seems to have a direct correlation with the risk of developing gum irritation. Teeth whitening gels containing lower levels of peroxide are typically assumed to provide less potential for creating gum irritation than those containing higher levels of peroxide.
In the case of tray-based teeth whitening products, gum sensitivity can also be caused by trauma from the bleaching tray being used. This fact is evidenced by a study that found that 18% of its participants developed sensitivity, despite the fact that the bleaching tray that they had worn did not contain any whitener.
When a dentist custom fabricates a bleaching tray for a patient they will usually make the it out of a soft flexible plastic that has been trimmed in a scalloped fashion so the edges of the tray end just at the user's gum line. This type of bleaching tray design minimizes any mechanical trauma that might occur due to the edges of the tray rubbing against the user's gums. It also minimizes the contact of the peroxide bleaching gel with the gums.
Over-the-counter teeth whitening products usually make use of stock bleaching trays (as opposed to custom fabricated ones) and this tends to place the user at a greater chance for developing gum sensitivity during the whitening process. The tray itself can rub against and irritate gum tissue. The fact that the tray overlaps onto and covers over a portion of a person's gums means that the tray will hold the whitening gel in direct contact with these tissues, thus providing a potential source of gum irritation.
Since the source of some gum irritation can be related to trauma produced by the bleaching tray itself one might anticipate that a "trayless" form of peroxide-based teeth whitening (
paint-on or whitening strips) might be a better choice. This may be a good solution for you. Only experimentation can provide a definitive answer.
Keep in mind that it can be the peroxide whitener that is the cause of the gum irritation, as opposed to the bleaching tray. A tray-based system utilizing a custom fabricated tray may do a better job of containing the bleaching agent and minimizing its contact with the user's gums than a "trayless" whitening process. At least two clinical studies have found a greater incidence of gum sensitivity with persons using whitening strips than with persons using custom tray whitening with 10% carbamide peroxide bleaching gel.
Also keep in mind that paint-on teeth whitening methodology typically involves the use of whiteners that have relatively high peroxide concentrations. As we've stated previously, higher concentrations of peroxides are typically associated with a higher incidence of gum sensitivity.