The surface of natural teeth when looked at under the microscope are covered with tiny, microscopic pores called tubules. These surface pores act as traps for small particles of food on the superficial layer of the tooth and result in staining and discoloration. Teeth staining is a natural phenomenon, and it greatly depends on diet of the individual and social habits such as smoking. Having good oral hygiene improves overall appearance of teeth and limits the extent of staining.
Prior to bleaching teeth, dental professionals must ensure teeth that will be encountering the whitening material, are free of any cavity, have no exposed dentin, have no prior history of sensitivity and are in good periodontal health. This evaluation is done during examination of the teeth and oral cavity, and it is a very critical step. For example, a tooth with extensive cavity or dentin exposure will not benefit from whitening. In fact, contact with whitening material may result in irreversible damage to the tooth, killing the pulp and causing excessive pain and discomfort that may require a root canal to resolve the problem.
Additionally, periodontal status of gums surrounding must be considered. Teeth whitening is to be only done on patients with minimal periodontal issues. Diseases such as sever gingivitis and bleeding gums, and periodontitis will affect the outcome of the bleaching, in addition to making the whitening process difficult and uncomfortable to patients. Therefore, a patient who has not seen a dentist for a while should be examined thoroughly to identify any untreated dental cavity, and periodontal disorder prior to dental whitening.
Material used for dental whitening
Material used for dental whitening are different concentrations of Carbamide Peroxide. C. Peroxide is a safe chemical with ability to eliminate stain particles from tiny tubules on the surface of the teeth without causing any damage to the tooth. Concentration of the bleach depends on the extent of bleaching desired and level of existing dental sensitivity in a patient.
Methods of Bleaching
There are two methods of in office dental whitening. Method one involves the use of a high intensity blue light, and second method relies on a higher concentration of bleaching without use of light. The differences between the two methods are:
Light achieves a faster whitening effect as it dries and desiccates the tooth. However, bleaching teeth with blue light results in greater sensitivity that may last for an extent period.
The bleach only method uses a higher concentration of dental whitening material, concentration of 30%- 45%, without any use of light. The advantage of not using the high intensity light is prevention of sensitivity after treatment.
Multiple meta-analyses of the effects of light vs no light have been studied and have shown no significant difference in the long term whitening effect of either method with the difference of extended post whitening complication using high intensity blue light.
Home care Instructions
Following the post operative instructions are very important to longevity of the whitening effect. Patients are refrained from eating or drinking food and drinks that are known to cause staining of the the teeth, such as coffee, soda, wine, tomato-based sauce, etc. Patient are encouraged to refrain from above foods and drinks starting immediately after treatment and continuing to up to three days after. During the first 72 hours after teeth whitening, saliva forms a protective layer over enamel of the teeth to slowdown and inhibit rapid discoloration.