How teeth whitening works
Whitening gels contain hydrogen peroxide or carbamide peroxide. The peroxide breaks stains inside the tooth into smaller pieces, so the colour is less concentrated and the teeth look lighter (ADA). Whitening toothpastes are different: they use mild abrasives that remove surface stains only, and do not change the tooth's own colour (same source).
In-clinic vs at-home vs shop-bought whitening
| In-clinic whitening | At-home with dentist's trays | Shop-bought strips and kits | |
|---|---|---|---|
| Where | At the dental clinic | At home, with trays made for your teeth | At home |
| How long it takes | Usually one visit | A few days to a few weeks | Varies by product |
| Gel strength | Highest | Lower than in-clinic | Lowest |
| Supervision | Dentist protects your gums and applies the gel | Dentist gives instructions and checks progress | None |
Sources: ADA, Oral Health Foundation.
Which is better: in-clinic or at-home?
Both work. A review of studies comparing the two found no meaningful difference in how much lighter the teeth became, and similar rates of sensitivity (Aidos et al., umbrella review). The choice is mostly about speed and preference:
- In-clinic suits you if you want a result quickly, for example before a wedding or an event.
- At-home with custom trays suits you if you prefer a gradual change and want to choose when to whiten.
- Some people combine both: one clinic session, then trays to finish or top up.
Is teeth whitening safe?
Whitening is considered safe when it is done or supervised by a dentist and the instructions are followed. The most common side effect is tooth sensitivity, which happens when peroxide reaches the inner layer of the tooth. In most cases it is temporary (ADA). Using whitening products too often or for too long can damage enamel and gums (same source).
The UK's Oral Health Foundation warns against whitening from beauty salons, kiosks or products of unknown origin, which can cause chemical burns and lasting damage to teeth and gums (Oral Health Foundation).
What whitening can and cannot change
- Yellow teeth usually whiten well.
- Brown teeth may respond less well.
- Grey teeth may not whiten at all.
- Crowns, veneers and fillings do not change colour.
- Stains from some medicines or a tooth injury respond poorly.
Source: ADA. If you have crowns or fillings on your front teeth, ask your dentist before whitening. They may need replacing afterwards to match your new shade.
How long does teeth whitening last?
Results are thought to last up to three years, but this varies from person to person. Coffee, tea, other strongly coloured food and drink, and smoking make the colour fade sooner (Oral Health Foundation). A top-up session can refresh the shade.
Before you whiten
Have a check-up first. Decay and gum disease should be treated before whitening, and a professional cleaning removes surface stain and tartar so the gel works evenly. Read our guide to dental check-ups and teeth cleaning.
Is teeth whitening covered by insurance in the UAE?
Usually not. Teeth whitening is a cosmetic treatment, and insurance plans in the UAE usually exclude cosmetic dentistry. If you are unsure, the clinic can check your plan with your insurer. See our insurance page.
Teeth whitening at Ibn Al Haitham Medical Centre
Ibn Al Haitham Medical Centre in Umm Hurrair, Dubai, offers in-clinic teeth whitening. Sessions are carried out by Dr. Rim Akrama, Implantology & Cosmetic Dentistry (DHA licence 77235171-003), using the Flash whitening machine and equipment. Before whitening, Dr. Rim checks your gums and any fillings, crowns or veneers, and records your starting shade. At our clinic, whitening is not recommended during pregnancy or breastfeeding. Read more about teeth whitening at our clinic or cosmetic dentistry.
Frequently asked questions
Is in-clinic or at-home teeth whitening better?
Both give similar results. In-clinic whitening is faster, usually one visit. At-home whitening with your dentist's trays takes a few days to a few weeks.
Does teeth whitening damage enamel?
Whitening done or supervised by a dentist, following the instructions, is considered safe. Overusing whitening products can damage enamel and gums.
How long does teeth whitening last?
Up to about three years, depending on diet and smoking. Coffee, tea and smoking make the colour fade sooner.
Do crowns and veneers whiten?
No. Crowns, veneers and fillings keep their colour and may need replacing to match whitened teeth.
Is teeth whitening covered by insurance in Dubai?
Usually not, because it is a cosmetic treatment. Your clinic can check your plan.