Teeth whitening: what you can realistically expect

Whitening is one of the simplest cosmetic treatments, but also one that comes with a lot of mistaken expectations. In short: teeth usually become noticeably lighter, but how much lighter depends on what they were like to begin with.

What whitening changes, and what it doesn't

Whitening gel passes through the enamel and breaks down the coloured compounds inside the tooth. That is why it changes the natural colour of the tooth, not just the surface.

• Respond well: teeth that have yellowed with age or from coffee, tea and cigarettes.
• Respond less well: greyish teeth, discolouration from certain medicines taken in childhood, and a single tooth that has darkened after an injury.
• Don't change colour: fillings, crowns and veneers. If you have visible fillings on your front teeth, after whitening they may look darker than the teeth around them, so they sometimes need replacing. This is done only after two weeks, once the colour has settled.

That is why we always do an examination before whitening. We check that there is no decay, no inflamed gums and no exposed tooth necks (the parts next to the gum where the gum has receded), because in those spots the gel could cause sharp pain. We often do a scale and polish first, too. After that, some patients decide it was all they needed.

Is it harmful?

According to research so far, whitening under a dentist's supervision does not damage healthy enamel. The most common side effect is sensitivity to cold, which usually lasts one to three days. To make it milder, we recommend using a toothpaste for sensitive teeth for two weeks before treatment, and at the clinic we also use a desensitising gel. The gums can be briefly irritated, so we protect them during treatment.

We don't recommend whitening during pregnancy or breastfeeding, or for anyone under 18.

At the clinic or at home

In-clinic whitening takes about 90 minutes and costs 28,000 RSD. You see the result the same day.

Home whitening with trays costs 22,000 RSD. We make trays to fit your teeth, and you wear them with the gel at home following our instructions, usually for two to three weeks. Teeth lighten gradually, and many people find the sensitivity milder. You keep the trays, so later on you can refresh the colour with a little gel.

How long the result lasts, and what doesn't help

This depends mostly on your habits. For some patients the colour stays stable for years; for others, slight darkening shows after a few months. Coffee, tea, red wine and smoking speed it up. In the first 48 hours after treatment, teeth pick up colour most easily, so during that time avoid coffee, tea, red wine, beetroot, curry and cigarettes.

What is best skipped. Whitening toothpastes mostly remove only surface stains, and the more abrasive ones can wear down enamel over time. Charcoal powder and baking soda also wear enamel, and lemon juice is acidic and dissolves it. Over-the-counter strips use a weaker gel and often give an uneven colour.

If the colour doesn't change enough, there are other options, such as veneers. They are worth discussing only once you can see how much whitening has helped.