Teeth whitening: what it changes, and what it leaves alone

Whitening and cleaning are not the same treatment

This is the most common misunderstanding in the whole subject, and the most expensive one. Somebody looks in the mirror, sees teeth that are duller and browner than they remember, and books whitening. Very often what they needed was a scaling and polishing.

The distinction is simple. Scaling and polishing removes what is sitting on the tooth: hardened plaque, tartar along the gumline, and the film that tea, karak and coffee leave behind. Whitening changes the colour of the tooth itself, the shade of the enamel and of the dentine underneath it.

If the problem is stain, cleaning is the answer. If the teeth are already clean and simply darker in shade than you would like, whitening is the answer. Plenty of people arrive convinced they need the second when they only needed the first. They have the polish, look in the mirror, decide they are content, and go home without paying for a treatment they did not need. If that is what we see, we say so before you agree to anything.

What whitening can genuinely change

The gel lifts colour out of the enamel and the dentine beneath it. The discolouration it handles best is the ordinary yellowing that arrives with age, with years of tea and coffee, and with enamel thinning enough to let the darker layer underneath show through.

Two to four shades is a realistic result for most people with that kind of discolouration. Teeth have a natural limit, and no honest clinic can promise you a specific shade before it has looked in your mouth. Anybody naming a shade in advance is selling rather than assessing.

It is worth saying plainly that whitening is cosmetic. It does not treat decay, it does not treat gum disease, and it does not make a tooth any stronger. A tooth can be very white and in poor condition. Where there is decay or inflammation, that is dealt with first, partly because it matters more and partly because whitening gel over sore gums is miserable.

What whitening cannot change

Crowns, veneers and white fillings stay exactly as they are

Whitening acts on natural tooth structure. It has no effect at all on porcelain or on composite. A crown on a front tooth, a veneer, or a white filling on a surface that shows will stay the shade it already is while everything around it lifts. On a back tooth nobody will ever notice. On a front tooth it can leave you looking worse than when you started, because the crown that used to blend now stands out.

That does not rule whitening out. It means the order matters. Whiten first, let the shade settle for a fortnight, then have the crown or the filling matched to the new colour. If the restoration is already there and you are content with how it looks, whitening may not be the sensible spend.

Grey responds worse than yellow

Yellow discolouration lifts well. It is the common kind and it is what whitening was designed for. Grey is harder. Grey shades usually come from within the tooth, sometimes from tetracycline antibiotics taken in childhood, and they lift slowly, unevenly, and sometimes not at all. You should be told which category you are in before you decide, not afterwards.

One dark tooth is usually a different problem

A single tooth that has gone grey or brown while its neighbours stayed normal is rarely a staining problem. It is usually a tooth whose nerve has died, often years after a knock to the mouth that seemed minor at the time. Whitening will not correct it, because the colour is coming from the inside. That tooth needs examining and x-raying, and the answer is frequently root canal treatment rather than whitening. An entirely different treatment, and the whitening would have fixed nothing.

Why the scaling and polishing has to happen first

Whitening gel placed over tartar and surface film does very little. Worse, it does very little unevenly. The gel reaches clean enamel and lifts it, then meets a band of hardened plaque along the gumline and stops, so the result comes out patchy and the darkest areas stay dark.

That is why the scaling and polishing at Al Najma is part of the same whitening appointment rather than something added on separately afterwards. The tartar comes off, the teeth are polished, the gums are protected with a barrier, and only then does the gel go on. It also gives us a proper look at the teeth before anything is started, which is when a hidden cavity or an inflamed gum turns up.

The first forty-eight hours, and how long it lasts

Enamel is more porous straight after whitening, which makes the first two days the two that count. Keep dark drinks, tomato sauces, curries and coloured food away from your teeth for forty-eight hours. Mild sensitivity to cold in that period is normal and usually settles within a day or two.

After that, the honest answer on longevity is somewhere between six months and two years, and the range is that wide because it depends almost entirely on what you drink. Teeth do not un-whiten by themselves. They re-stain. Karak two or three times a day will pull the colour back within months. Strong black tea, Arabic coffee and espresso do the same, and shisha and smoking are harder on the result than any drink.

What genuinely helps:

• Rinse with plain water after tea or coffee. Not a full brushing, just water.
• Use a straw for iced coffee and cola where you can.
• Have a scaling and polishing once or twice a year. That keeps the result looking better for longer than repeat whitening ever will.
• Do not treat another round of whitening every few months as harmless. It is not, and it is rarely necessary.

If you are not sure which one you need

Come in for a check-up and ask. You will be told whether you need a clean, whitening, both, or nothing at all this year, and the answer is often the cheapest of those. You are told what the treatment costs before it starts, there is no consultation fee stacked on top, and the number does not move afterwards. How that works is explained on our pricing page. We take cash and card only, and you leave with a stamped invoice and a completed reimbursement form so you can claim from your insurer yourself.

Common questions