Teeth whitening is the most conservative treatment for discolored teeth compared to more invasive procedures like composites, veneers, or crowns. It offers a simple, cost-effective, and time-saving alternative.
There are many ways to whiten teeth. Most are well accepted and safe if used properly. Some whitening methods are done at home. Other whitening methods are done professionally like zoom whitening system in Etobicoke, ON. One of the most common complications for whitening teeth is teeth sensitivity. Lets dive into more details about teeth sensitivity and pain after whitening.
Teeth stains and discolored teeth
Stains vary in nature and presentation and may result from aging, chromogenic food/drink (e.g., coffee or wine), tobacco, microcracks in enamel, excessive fluoride, severe jaundice in infancy, dental caries, restorations, thinning of the enamel layer, tetracycline, and other medications. Stains are classified as extrinsic (residing on the surface of the tooth) or intrinsic (contained within the tooth). Extrinsic stains may be removed mechanically from the surface of the tooth by polishing, microabrasion procedures, or abrasives in “whitening” toothpastes. Intrinsic stains are removed solely by bleaching.
- Causes of Stains
- Aging, chromogenic food/drink (e.g., coffee or wine), tobacco, enamel microcracks, excessive fluoride, severe jaundice in infancy, dental caries, restorations, thinning enamel layer, tetracycline, and other medications.
- Classified as extrinsic (surface) or intrinsic (within the tooth).
- Types of Stains
- Extrinsic stains: Removed mechanically (polishing, microabrasion, whitening toothpaste).
- Intrinsic stains: Removed by bleaching.
Some stains respond more favorably to bleaching than others. For example, smoking and chromogenic food stains respond well to bleaching, whereas blue/gray tetracycline stains respond the slowest. Yellow discoloration responds quickly in contrast to white spots, which don’t respond to bleaching but become less noticeable as the tooth background is whitened. Understanding the nature of the stain along with an accurate diagnosis can help determine which patients will respond more favorably to bleaching.
Teeth whitening products
All teeth whitening agents are oxidizing agents that penetrate the enamel and dentin to dislodge or break down the chromatic particles. Hydrogen peroxide acts by diffusing through the enamel and dentin, releasing free radicals that react with other unsaturated bonds, converting more highly pigmented carbon-ring compounds to smaller hydroxyl groups, which are colorless. The simpler molecules reflect less light, making the tooth appear lighter in shade. Carbamide peroxide is hydrogen peroxide with the addition of urea as a stabilizer and the active ingredient hydrogen peroxide as the whitening agent.
Causes of Tooth Sensitivity
Tooth sensitivity is the most common side effect of bleaching and generally increases when the concentration of bleaching agent and length of contact time is increased. It has been demonstrated that peroxide penetrates through the tooth to the pulp in a matter of minutes and may cause a mild, reversible inflammatory response of the pulp. This can result in tooth sensitivity, but if the pulp remains healthy, the sensitivity is completely reversible. Although the etiology of tooth sensitivity is not completely understood, it has been proposed that stain removal can open dentinal tubules and increase tooth sensitivity. This explanation is consistent with Brannstrom’s hydrodynamic theory, which proposes that the movement of fluid within the dentinal tubules can elicit a painful response.
The incidence of tooth sensitivity during home bleaching has been reported to be 25% to 70%; however, 20% to 30% of patients reported sensitivity to the placebo gel, and 18% were sensitive with the bleaching tray alone. Tooth sensitivity may be more likely in the presence of large pulps, exposed root surfaces, erosion, abrasion, abfraction, and/or after severe enamel loss, but there are no reliable predictors for which patients will experience sensitivity.
The best way to manage sensitivity after whitening is to
- Use fluoride and desensitizing gels to occlude dentinal tubules and reduce nerve transmission.
- Protect gingiva with proper application techniques and proper fitting trays.
Management
To help lessen the effect of sensitivity, the duration or frequency of application can be reduced as well as the concentration of carbamide or hydrogen peroxide gel used. Patients who are bleaching at home can interrupt the process for a day or so for the teeth to recover before resuming bleaching. Sensitivity during in-office treatment can be managed with desensitizing gel application, anti-inflammatory medication (e.g., ibuprofen), and/or ceasing the session.
Alternatively, professional whitening done in dental office is known to produce less sensitivity. Dentist applied whitening treatments are well controlled and professionally managed.
Management of Tooth Sensitivity
- Reducing Sensitivity
- Decrease application duration/frequency or concentration of bleaching agents.
- Interrupt home bleaching for recovery.
- In-office treatments: Desensitizing gel, anti-inflammatory medication, session cessation.
- Fluoride and Desensitizing Products
- Fluoride: Acts as a tubule blocker (e.g., ProDenRx, Fluoridex Daily Defense, Sensodyne toothpaste).
- Calcium and phosphate pastes: Reduce sensitivity (e.g., Prospec MI Paste).
- Potassium nitrate gels: Depolarize nerve fibers for numbing effect (e.g., UltraEZ, Relief ACP).
Soft-Tissue Sensitivity
- Preventing Chemical Burns
- Use rubber dam isolation or resin dams during in-office bleaching.
- Treat minor exposure with antiseptic ointment.
- Home bleaching: Avoid ill-fitting trays and excessive dosages/exposure times.
