Teeth whitening or bleaching is a cost effective and minimally invasive way to improve your smile. White smile is often desirable. When teeth become yellowish over time, our dentist can lighten the shade of natural teeth without drilling or adding to the tooth structure.
Hydrogen Peroxide (H2O2) is the most commonly used active ingredient in whitening product. It is often delivered as either hydrogen peroxide or its predecessor carbamide peroxide. When in contact with water, carbamide peroxide converts into hydrogen peroxide at a ratio of 3:1. For example, whitening product containing 30% carbamide peroxide has about 10% of hydrogen peroxide.
As a powerful oxidising agent, hydrogen peroxide diffuses into the tooth, breaking down to produce free radical oxygen. These unstable free radical then attach to the organic pigment molecules to form smaller and less pigmented molecules which reflect less light to give whitening effect.
Types of whitening
Different whitening product in different delivery method manipulates the duration of exposure and concentration of hydrogen peroxide to achieve the desirable result.
- Immediate visible result after 1 hour
- Done by professional dentist at dental clinic
- High concentration of hydrogen peroxide (15-40%)
- No compliance issue
- Lower concentration of HP (4-15%) or CP (10-35%)
- Fabricate a custom made tray at dental clinic
- Dispense whitening gel on the tray and wear at home
- Wear 2-8 hours daily for duration of 2 weeks
- Budget friendly but requires good compliance from patient
Other whitening products
- in form of whitening strip, pen or toothpaste
- low concentration of hydrogen peroxide (usually <5%)
- ideal for maintenance after professional whitening
Teeth Whitening FAQ
1. Will teeth whitening cause tooth sensitivity ?
Yes. Mild sensitivity is relatively common. It is usually temporary and will go away once you have completed the whitening process. Most whitening products contain desensitizing ingredient to help reduce sensitivity and provide additional patient comfort.
2. Any dental condition which is contraindicated in teeth whitening ?
Whitening is only effective on natural teeth. Existing fillings, veneers and crowns will not change color after in contact with whitening gel. However, untreated dental problem such as gum recession, tooth decay and abrasion cavity will lead to severe tooth sensitivity during the whitening process.
3. Is it safe for pregnant woman ?
No, it is not recommended. (FDA Pregnancy Category C – No adequate evidence to prove it is safe during pregnancy)
4. Will it damage my teeth ?
Professional teeth whitening using HP or CP will not weaken or thin down the enamel. To be effective and safe at the same time, high concentration of HP will require gum protection and close monitoring of the concentration and time. Therefore, it is not advisable to use unknown whitening product.
5. How long the whitening effect will last ?
Whitening result is usually very stable and can last up to few years. Thing like oral hygiene, diet (coffee, wine) and habit (smoking) may affect the longevity of the result. Fortunately, follow up treatment or product are easy and fast, helping you to get your bright white smile back.