Teeth whitening is one of the most frequently discussed and debated topics in modern dentistry. The history of attempts to lighten teeth dates back over 130 years, with significant advancements over time leading to today’s high levels of safety and effectiveness.
Among current esthetic treatments, teeth whitening stands out as the most conservative option. This procedure involves using a chemical agent that, through an oxidation-reduction reaction, alters the optical properties of dental enamel. It’s a straightforward and cost-effective alternative compared to other cosmetic dental procedures.
Aesthetics, by definition, is the science of beauty, identifying specific details in objects—whether animate or inanimate—that make them visually appealing. While skin and body features are commonly considered in physical appearance, the role of teeth, particularly their color, is crucial in shaping facial expression.
Historically, different cultures have viewed dental pigmentation differently. In ancient Asia, black or dark brown teeth (known as ohaguro) were seen as a sign of nobility. The Mayans inlaid their teeth with precious stones or jade for color. Even today, some African tribes use red, orange, or black pigmentation for decorative purposes.
In contrast, modern Western culture values white, well-contoured, and properly aligned teeth as the standard of beauty. These features are not only seen as attractive but also as indicators of health, self-esteem, status, pride, and personality.
Teeth and their color play a very important and marked role in modifying facial expression.
In our western culture white, well contoured and aligned teeth set the standard of beauty.
Types of Dental Pigmentations
Extrinsic Pigmentations: These are surface-level stains that are easily removed. They can result from the accumulation of bacterial plaque, dental calculus, tobacco use, dark-colored beverages (like tea, coffee, and wine), dental caries, or certain mouthwashes (such as those containing chlorhexidine).
Intrinsic Pigmentations: These are deeper stains within the dental structure, making them more challenging to remove. They are further classified as:
- Pre-eruptive: Occurring within the first year of life, such as in amelogenesis imperfecta, fetal erythroblastosis (dentinogenesis imperfecta), or dental fluorosis (often due to tetracycline use).
- Post-eruptive: Caused by factors like trauma (pulp hemorrhage, pulp necrosis, or root resorption), antibiotics (e.g., tetracyclines), incorrect endocrinological treatment, physiological aging, or caries.
Iatrogenic: Resulting from the use of metallic filling materials, like amalgam.
Lightening or oxidizing agents:
- Various chemical oxidants have been used over time, including hydrogen peroxide, sodium perborate, carbamide peroxide, and urea peroxide, each in different concentrations.
- Mechanism of Action: The whitening agent penetrates the enamel’s prisms, releasing oxygen and producing an oxidation reaction that lightens the pigmented surface.
- Methods: Before beginning a teeth whitening treatment, it is crucial to perform a dental prophylaxis and examination to check for caries, pigmentations, enamel fractures, or exposed necks.
Alternatives:
Depending on the diagnosis and type of tooth pigmentations your dentist will recommend which agent, concentration and method to follow.
- In-Office Whitening: This method involves applying a whitening agent—typically hydrogen peroxide—directly to the tooth’s surface for about 20 minutes per session, with the number of sessions depending on the desired result.
- At-Home Whitening (with trays): Here, carbamide peroxide is the most commonly used agent. Custom acetate trays are made from impressions of the patient’s teeth, and the patient applies the whitening gel at home. The application time varies between 6-8 hours at night or 2-4 hours during the day, typically for 2-4 weeks.
In many cases, dentists may combine both methods for more uniform and optimal results.
Durability of Results: While the outcomes of whitening treatments can be unpredictable, over 90% of patients report complete satisfaction. Post-treatment, it is recommended to use specialized creams and rinses to maintain the results and schedule follow-up visits, as teeth may gradually revert to their original tone, potentially requiring touch-ups.