Non-Vital Dental Bleaching Techniques

Bleaching teeth has become a regular practice for many people. Bleaching gets done in dental offices with appropriate equipment and at home with over-the-counter supplies as well. One bleaching process that will undoubtedly require the assistance of a dentist, is the bleaching of a non-vital, or dead tooth. There are two very good methods to whiten a non-vital tooth. The decision of which one to use is dependent on the shade and location of the tooth.

Non-Vital Teeth

• A tooth becomes non-vital when the pulp, or nerve of the tooth becomes necrotic, or dead. A tooth can die because of a filling being placed too close, decay penetrating the nerve chamber of the tooth, the nerve snapping off at the apex. A non-vital tooth loses the blood and water supply, making it tremendously fragile and subject to darkening over time. A root canal can be done to save the tooth, but will do nothing to preserve the color. The color change is intrinsic, or from inside the tooth and will not be improved with the traditional bleaching methods used on the outside of teeth.

Ideal Treatment for Non-Vital Teeth

• Because teeth become brittle after root canals, optimal treatment is to restore them with a core build-up and crown. A post and core build-up is for a posterior, or back tooth and is usually made of amalgam. The tooth is then prepared for a crown. On front teeth, a core build-up is only required if the tooth has broken down to the extent that there is extremely little tooth structure left to use for a crown. Otherwise, a standard crown is usually sufficient. A crown protects a fragile tooth from all sides and the color will never get darker than the materuak the crown fabrication is from, in most cases on front teeth, porcelain.

Walking Bleach Technique

• The least invasive method of internal bleaching of non-vital teeth is the walking bleach technique. A small hole is drilled into the lingual, or tongue side of the tooth, to place a cotton pellet with a mixture of water and sodium perborate. The hole is then sealed with Cavit, a soft temporary filling. It takes more than one session of bleaching to be effective, in some cases many sessions of about 40 minutes each. After 40 minutes, the Cavit is removed along with the cotton pellet. More Cavit is then placed, sealing the hole in the tooth until the next appointment. Follow-up appointments are necessary to evaluate the success of the bleaching and re-apply the patient is satisfied.

Thermo-catalytic Bleach Technique

• Thermo-catalyic bleaching is more invasive than the walking bleach technique. The approach though is similar. A hole is drilled into the tongue side of the tooth, but the bleaching material is much stronger and somewhat caustic. The material used is Superoxyl -- a 35 percent concentration, hydrogen peroxide and heat. The Superoxyl and hydrogen peroxide are placed in the tooth on a cotton pellet, then sealed in with Cavit. Heat is applied to the tooth for 30 or 40 minutes. The Cavit will be removed with the cotton and bleach, then re-sealed with Cavit until the next appointment. Appointments are scheduled regularly to evaluate the results and re-apply for as long as necessary. While this method is faster because of the strength of the materials used, it is also riskier. Superoxyl is a powerful bleach and can cause some irritation of the outer tissues and internally at the apex of the tooth.