Statement on the Safety and Effectiveness of Tooth Whitening Products
ADA Council on Scientific Affairs
For the last two decades, the ADA Council on Scientific Affairs has monitored the development and the increasing numbers of tooth whitening products. As the market for these products grew, the Association recognized a need for uniform definitions when discussing whiteners.
For example, "whitening" is any process that will make teeth appear whiter. This can be achieved in two ways. A product can bleach the tooth, which means that it actually changes the natural tooth color. Bleaching products contain peroxide(s) that help remove deep (intrinsic) and surface (extrinsic) stains. By contrast, non-bleaching whitening products contain agents that work by physical or chemical action to help remove surface stains only.
Whitening products may be administered by dentists in the dental office, dispensed by dentists for home-use, or purchased over-the-counter (OTC), and can be categorized into two major groups:
- Peroxide-containing bleaching agents; and
- Whitening toothpastes (dentifrices)
Peroxide-containing bleaching agents
Carbamide peroxide, used in many bleaching products, breaks down into hydrogen peroxide and urea, with hydrogen peroxide being the active bleaching agent. A bleaching product containing 10 percent carbamide peroxide yields approximately 3.5 percent hydrogen peroxide. The most commonly observed side effects with these peroxide-based bleaching agents are tooth sensitivity and occasional irritation of soft tissues in the mouth (oral mucosa), particularly the gums. Tooth sensitivity often occurs during early stages of bleaching treatment. Tissue irritation may result from an ill-fitting tray used to contain bleaching product. Both tooth sensitivity and tissue irritation are usually temporary and stop after the treatment. On rare occasions, irreversible tooth damage has been reported. Patients should be cautioned that not enough information is available to support unsupervised long-term and/or repeated use of bleaching products.
Dentist-dispensed and OTC home-use products
Dentist-dispensed and OTC home-use tooth whitening bleaches are eligible for the ADA Seal of Acceptance. The products in this category that currently bear the ADA Seal contain 10 percent carbamide peroxide; however, participation in the program is not limited to products of this concentration or type of bleach. There are many whitening product options currently available to consumers both from the dentist as well as from retail outlets, including gels placed in trays that cover the teeth, paint-on materials, bleaching strips and others. The level and type of active ingredients, the form of the product and how they are applied may vary widely.
In a water-based solution, carbamide peroxide breaks down into hydrogen peroxide and urea, with hydrogen peroxide being the active bleaching agent. Other ingredients of peroxide-containing tooth whiteners may include glycerin, carbopol, sodium hydroxide and flavoring agents.
Professionally applied bleaching products
There are many professionally applied tooth bleaching products used by dentists in office. These products use hydrogen peroxide in concentrations ranging from 25 percent to 40 percent and are sometimes used together with a light or laser, which the companies state accelerate or activate the whitening process. However, most studies have reported no additional long-term benefit with light-activated systems. Prior to application of professional products, gum tissues are protected either by isolation with a rubber dam or application of a gel. Whereas home-use products are intended for use over a two-to-four week period, the in-office professional procedure is usually completed in about one hour. Due to the discontinuation of the professional component of the Seal Program on December 31, 2007, professionally applied bleaching products are no longer eligible for the ADA Seal of Acceptance.
Whitening toothpastes (dentifrices) in the ADA Seal of Acceptance program contain polishing or or chemical agents that are designed to improve tooth appearance by removing surface stains. They do this through gentle polishing, chemical chelation, or some other non-bleaching actions. Several whitening toothpastes that are available OTC have received the ADA Seal of Acceptance.
The ADA recommends that if you choose to use a bleaching product, you should only do so after consultation with a dentist. This is especially important for patients with many fillings, crowns, and extremely dark stains. A thorough oral examination, performed by a licensed dentist, is essential to determine if bleaching is an appropriate course of treatment. The dentist and patient together can determine the most appropriate treatment. The dentist may then advise the patient and supervise the use of bleaching agents within the context of a comprehensive, appropriately sequenced treatment plan.