Teeth Whitening

How much whitening will achieve depends on why the tooth darkened. A decision made without that distinction produces some satisfied patients and some disappointed ones.

Extrinsic staining. Pigments accumulating on the enamel surface: tea, coffee, red wine, tobacco and some spices. It is superficial, responds very well to whitening, and part of it comes away with scaling alone.

Intrinsic discolouration. The colour comes from the dentine beneath the enamel. With age dentine thickens and darkens while enamel thins, so the underlying colour shows more. Peroxide does pass through enamel into dentine, so whitening acts on that layer too — but more slowly and less completely.

A single dark tooth. Seen in a tooth that has taken a knock or had root treatment. The treatment there is not external whitening but bleaching from inside the tooth; a different procedure.

Tetracycline and fluorosis staining. Discolouration built into the enamel during development. It responds poorly to bleaching, and promising whitening alone in those cases is not honest.

The active agent in whitening gel is hydrogen peroxide, or carbamide peroxide, its slower-releasing form. Enamel is permeable at a microscopic level; peroxide passes through it into the dentine and breaks down the organic molecules that give colour.

So whitening does not strip a layer from the tooth; it chemically alters the molecules producing the colour. That explains why the common worry about damaging enamel is misplaced — applied under clinical supervision, at the right concentration and for the right time, it does not cause lasting harm.

Light and laser systems are used to accelerate activation of the gel. Let us be honest here: current evidence suggests light activation adds little to the final result. Light systems can speed the appointment; they do not make the outcome whiter. A quote that does not tell you this is selling the light as an advantage.

Peroxide concentration regulations in Türkiye are aligned with European ones; the gels used in clinics are the same materials used in a European surgery. The difference is not the material but the control of the application.

The result is usually described as two to eight shades lighter, but that range depends on the starting colour and the type of discolouration. Promising a specific number of shades is not possible, and we do not.

There are two main approaches, and the best result usually comes from combining them. The difference between them is not strength but how the effect is distributed.

The standard approach here is a single in-clinic session plus custom trays made the same day from an intraoral scan. The clinic session produces a rapid change; the trays both complete the result and let you top it up months later when needed.

What holds the result is the trays. So be wary of an offer that says one clinic session is enough: nobody can guarantee the six-month appearance from a single appointment.

Over-the-counter products — whitening toothpastes, ready-made strips and kits bought online — are a different category. Whitening toothpastes lift surface stain through abrasion; they do not change the colour, and used long-term they wear the enamel. The main problem with ready-made kits is the unfitted tray: gel spills onto the gum and can cause a chemical burn.

The difference is not concentration but control: a custom tray, gum protection and the correct duration. Without those, even a low-concentration product can do harm.

Whitening is a safe procedure, but not for everyone and not in every situation. In the following it is either postponed or not carried out at all:

• Pregnancy and breastfeeding. No harm has been demonstrated, but it is elective and so is not done during that period.
• Under eighteen. Enamel and pulp are not yet mature.
• With active decay. Gel reaches the inside of the tooth through the cavity and causes severe pain. The decay is treated first.
• With untreated gum disease. Gel contact with inflamed tissue is uncomfortable and impedes healing.
• Where there is marked recession and exposed root surface. Root surface is not covered by enamel; it does not whiten and it becomes sensitive.
• In cracked or fractured teeth. Gel penetrates the crack.
• With a history of severe sensitivity. The sensitivity is managed first and whitening follows.

There is also a "possible but will not give the expected result" group, and saying so in advance matters: tetracycline staining, advanced fluorosis and teeth with markedly thinned enamel. Whitening produces some improvement in those cases but usually not enough; the right answer may be laminate veneers or composite bonding.

That last group is where whitening is most often mis-sold. Carrying it out in a case known not to respond spends the patient's time and money and loses their trust.

Sensitivity after whitening occurs to some degree in most patients. We do not write "in a small number of patients", because that is not accurate — and knowing the truth prevents alarm when it happens.

It is usually sensitivity to cold, beginning a few hours after the session and resolving within twenty-four to forty-eight hours. It is sometimes felt as sudden, sharp twinges lasting a few seconds. It comes from peroxide creating a temporary stimulus in the dentinal tubules and it is not lasting damage.

What we do to reduce it: desensitising agents containing fluoride and potassium nitrate before and after, adjusting session length to the individual, and setting concentration and wear time individually for home trays.

What you can do: avoid very hot and very cold drinks for two days, use a desensitising toothpaste, and if you are using home trays, skip a day when sensitivity increases.

If sensitivity lasts more than a few days or concentrates in one tooth, tell us. Pain focused on a single tooth may come not from the whitening but from an unnoticed crack or cavity in that tooth.

Where whitening sits in the plan directly determines whether the result lasts, and that order does not change.

1. Examination and radiographs first. Decay and gum health are assessed.
2. Decay and gum treatment where needed. Without exception, first.
3. Scaling. Done immediately before whitening; it lets the gel contact the tooth surface evenly and helps the result come out uniform.
4. Whitening. The clinic session and home trays.
5. Two weeks for the shade to settle. The most skipped step and the most important.
6. Then restorative work where planned. The shade of veneers, crowns and fillings is matched to that final colour.

The fifth and sixth steps together prevent the most common error. Ceramic and filling materials do not bleach. If natural teeth are whitened after restorations are placed, the resulting mismatch can only be corrected by remaking the ceramic — an expensive and unnecessary procedure.

The two-week wait is a genuine requirement too. The colour immediately after whitening is not the final one; the tooth is slightly dehydrated and looks lighter than it is, then rebounds a little over the following fortnight to settle at its true level. Shade matching has to be done against that settled colour.

We emphasise this particularly in smile design plans: for a patient travelling for treatment those two weeks are written into the plan from the start rather than compressed later.

Whitening is not permanent, and that should be said at the outset. Depending on habits and maintenance the result is generally held for one to two years; longer in some patients, much shorter in smokers.

What brings the colour back is extrinsic staining accumulating again. So maintaining the result is not about freezing day-one colour; it is about slowing new accumulation.

• Avoid staining food and drink for the first 48 hours — enamel behaves more absorbently during that period. Coffee, tea, red wine, cola, dark fruit juices, tomato sauce, soy sauce and beetroot are on that list.
• Afterwards, drink those through a straw and follow with water.
• Stop smoking — the single factor that brings the colour back fastest.
• Brush twice daily and clean between the teeth every day.
• Scaling every six months; part of the surface stain comes away there anyway.
• A short top-up with home trays once or twice a year.

A top-up is much shorter than the original treatment: a few days with the trays you already have is usually enough. Keeping the trays therefore matters — a lost tray means a new scan and new production.

Like every treatment carried out here, whitening carries a lifetime guarantee on materials and workmanship. One distinction is worth writing plainly: the guarantee covers the procedure and the making of your custom trays. Natural re-staining over time is not a defect but an expected process, and it is handled as a top-up.

A single tooth darker than its neighbours is an entirely different situation and does not respond to external whitening.

The cause is usually that the tooth has lost its vitality: after an old injury or root canal treatment, blood products left inside the tooth stain the dentine from within. Because the colour comes from inside, gel applied to the enamel does not change it.

The solution is internal bleaching. In a tooth whose root treatment is complete, a bleaching agent is placed into the crown chamber and sealed temporarily. The process is repeated at intervals of a few days; two to four sessions are usually enough.

The advantage is clear: no tooth is cut. Achieving the same result with a crown means removing structure all the way round. Where colour is the only problem, internal bleaching should be tried first.

The limits, stated too: the result of internal bleaching can regress somewhat over the years and is repeated when needed. And where the tooth has lost substantial structure or is at risk of fracture, the right answer is a veneer or a crown anyway — in those cases colour is a secondary issue.

In some cases whitening does not reach the result wanted, and knowing that in advance beats a wasted course of treatment. The options then:

The last row surprises patients most often. Whitening acts only on natural tooth tissue. If you have old composite fillings in the front teeth, the surrounding tooth lightens while the fillings stay as they were and the difference becomes obvious. Those fillings may therefore need replacing after whitening — and we plan for that from the start.

Trying whitening before moving to an alternative is the correct order in most cases: it is the least invasive option, and if it works no larger treatment is needed. A plan that proposes veneers without ever mentioning whitening has skipped the smallest option.

We tell you which group you fall into at the consultation and describe a realistic outcome. We use a measurable method: the starting shade is recorded against a shade guide and the result compared on the same guide. That replaces an argument about whether it worked with a recorded comparison.