Re: Dental Fluorosis Classification Criteria

[Anonymous]

I. External (vital) bleaching.
The first published report of bleaching was by Chapple in 1877 and involved the use of oxalic acid.

Indications.
-Mild, uniform, yellow discoloration(age darkening and fluorosis).
-Yellow to brown extrinsic/intrinsic staining(age darkening, fluorosis, tetracycline)
-Discoloration in the gray, blue gray or black range do not respond well to bleaching and tend to darken more rapidly .
-Teeth that exhibit color banding from tetracycline require special procedures to minimize the band effect.

Longevity.
Treatment is seldom permanent and a reliable prediction of the exact duration of color change is impossible. Generally, the color lightening lasts from 1 to 4 years, with the teeth gradually returning to their original color, partly due to age darkening.
The effect seems to last longer in young patients and yellow stains recur more slowly than blue/gray/black discoloration.
Risks.
Over the years, bleaching has been shown to be a relatively safe procedure. Certain risks which are associated with it can be adequately controlled by following the technique properly.
-Bleaching agents and heat application can produce pulpal changes.
-Bleaching agents can alter enamel and dentin structure. Reduction in the microhardness of both enamel and dentin has been reported.
-Peroxides have mutagenic potential and boost the effects of known carcinogens.
-Long term use can alter the oral flora.
-Potential for chemical burns of the soft tissues
-Bleaching can cause a reduction in the bond strength between composite materials and the enamel surface.
-Use of hydrogen peroxide for internal bleaching can lead to external cervical root resorption.

Technique.
Due to the technical nature of the procedure and the caustic nature of the materials involved, bleaching should be performed by the dentist. However, in today’s practice, bleaching can be done either as an office procedure or the patient may apply special bleaching materials at home under the instructions and recall monitoring of the dentist.

I. Dentist applied(office) bleaching
Materials.
-The commonly used bleaching agent, superoxol, which is 30-35% hydrogen peroxide should be kept refrigerated in a tightly capped, amber colored bottle or other opaque container. Under these conditions, the shelf life should be approximately 1 year.
-Ethyl ether may be mixed with superoxol in a 1:5 ratio and the mixture used for bleaching. The addition of ether lowers the surface tension of the liquid for better wetting and enhances the penetration of superoxol into the tooth structure.
-Phosphoric acid etching gel. Etching the enamel surface prior to bleaching increases the porosity of the enamel and allows greater penetration of the bleach.

Activation.
The application of heat accelerate the reactivity of bleaching agent and shorten the treatment time. Effective temperature that do not produce undue pulpal reaction are in the range of 125-140° F (52-60° C).
-Heat can be applied with a metal instrument heated over a flame.
-But it is preferable to use a regulated heat source. there are three heating instruments currently marketed by Union Broach Company.
1.Union Broach heating paddle, a heating instrument with interchangeable metal tips and good heat regulation.
2. New Image Bleaching Unit, a heat lamp with built-in timer and temperature regulation.
3. The Illuminator, a combination unit with both heat lamp and heating paddle.