Cosmetic Dentistry
Teeth whitening
Lightening the internal shade of the tooth, without touching its structure.
Professional whitening uses a peroxide-based gel that lightens the internal shade of the tooth, without touching its structure. It is done in the chair, at home with custom-made trays, or as a combination. It works on natural teeth, and on those only.
A prerequisite that is not a formality
The gel does not whiten what is dirty: a scaling always precedes the session, otherwise the shade you get is the shade of the tartar.
More importantly, it is not applied over decay or inflamed gums. Peroxide passes through any break in the enamel and reaches the pulp: on a decayed tooth the session becomes painful and can force a root treatment. The initial assessment checks this first.
In the chair or at home
- In the chair: higher concentration, gums protected by a barrier, result visible from the session
- At home: custom trays, weaker gel, worn a few hours a day for one to two weeks
- Combined: one session in the chair to start, then maintenance at home
The end result is comparable. The difference lies in pace and sensitivity: the home protocol, being more gradual, is better tolerated by sensitive teeth.
What whitening does not change
Existing crowns, veneers and composite fillings do not shift a single shade. After whitening they therefore look darker than the neighbouring teeth, and replacing them sometimes becomes necessary to restore a consistent look.
That has to be anticipated BEFORE starting, not after: it is the most common disappointment, and the most avoidable.
A root-treated tooth that has darkened does not respond to external whitening either: it calls for internal bleaching, carried out from inside the tooth.
Sensitivity and how long it lasts
Sensitivity to cold during treatment is common and temporary. It settles by spacing out applications and using a desensitising toothpaste.
The result fades with time, faster if you regularly drink tea or coffee, or smoke. A top-up session at regular intervals maintains it. No fixed duration can be quoted: it depends on individual habits.
Frequently asked questions
Does whitening damage enamel?
Carried out by a dentist, with controlled concentrations and timings, it does not alter the structure of the enamel. The risk lies with poorly dosed over-the-counter products and repeated unsupervised use, which cause sensitivity and gum irritation.
Are pharmacy kits equivalent?
No. Their concentration is capped by regulation, and above all the tray is not fitted: gel spills onto the gum and burns it. Without a prior assessment they also get applied to decayed teeth, which is the real danger.
Can I whiten during pregnancy?
Whitening is postponed during pregnancy and breastfeeding. It is not urgent, and the lack of sufficient data justifies waiting. Scaling and treatment, however, remain recommended.
This page is for information only. It is not a diagnosis, personalised medical advice or a prescription. Only a clinical examination can establish a diagnosis and lead to a treatment plan.
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