Whitening is not usually painful, but temporary sensitivity is common and normally settles within a few days. It is reduced by a dental check beforehand, gum protection during treatment, desensitising toothpaste, and avoiding very hot or cold food for a day or two. In Singapore, whitening products above 6% hydrogen peroxide can only be used by a registered dentist. Whitening is not recommended during pregnancy or breastfeeding, for children and teenagers, or before decay and gum disease are treated.
Why Does Whitening Cause Sensitivity?
Whitening gel works by letting peroxide pass through the enamel to break down stains. For a short time, this can make the inner layer of the tooth (the dentine) more responsive to temperature, so cold drinks or air can cause a quick, sharp twinge. This is usually temporary. Gum irritation can also happen if gel touches the gums, which is why your dentist places a protective barrier first.
How to Reduce Sensitivity
- Before: if your teeth are already sensitive, start a desensitising toothpaste one to two weeks before treatment, and tell your dentist.
- During: your dentist protects your gums and checks on your comfort between rounds of gel.
- After: keep food and drinks lukewarm for a day or two, brush gently with a soft brush and desensitising toothpaste, and skip acidic drinks.
- Take-home kits: if your teeth feel sensitive, you can usually pause for a day. Ask your dentist before changing how often you wear the trays.
Contact your dentist if pain is severe, affects one tooth in particular, or doesn't settle within a few days. These can be signs of a crack or decay that needs checking. See sensitive teeth to cold for other causes.
Is Teeth Whitening Safe?
Professional whitening is considered safe when a dentist checks your teeth first and carries it out or prescribes it. Singapore draws clear lines:
| Who | Hydrogen peroxide limit |
|---|---|
| Over-the-counter products (e.g. toothpaste) | Up to 0.1% |
| Dentist-prescribed home use | Up to 6% |
| Professional in-clinic use | Above 6%, by a registered dental practitioner only |
Source: Singapore Dental Association guidance on tooth whitening.
At Trust Dental, whitening is done by our dentists, after a check of your teeth and gums. In-clinic whitening is $588 before GST, in one visit of under 2 hours.
See teeth whitening at Trust DentalWho Should Not Whiten (Yet)
- Pregnant or breastfeeding: whitening is usually postponed.
- Children and teenagers: not recommended while teeth are still developing.
- Untreated decay or gum disease: treat these first. Whitening gel on exposed or decayed areas can be painful.
- Exposed roots or receding gums: roots don't whiten and can be sensitive (see receding gums).
- Crowns, veneers or fillings on front teeth: these won't change colour, so plan with your dentist.
- A single dark tooth: this may need a different approach (see discoloured tooth).
Does Whitening Damage Enamel?
When used as directed by a dentist, professional whitening is not considered to damage enamel. The risks come from overuse, products of unknown strength, and whitening without a dental check. Abrasive "whitening" scrubs and DIY remedies can wear enamel over time.
