Teeth whitening is the most requested cosmetic dental procedure in the world — and also the most misunderstood. From supermarket strips to professional laser whitening, there's a huge range of options with very different results. This guide cuts through the noise.

Why Do Teeth Discolour?

Teeth discolour through two main mechanisms. Extrinsic staining affects the outer enamel surface and is caused by coffee, tea, red wine, tobacco, and certain foods. This type responds well to whitening. Intrinsic discolouration happens within the tooth itself — caused by ageing, tetracycline antibiotics, fluorosis, or trauma. This is harder to whiten and may require veneers for the best result.

Over-the-Counter Products: The Truth

Whitening toothpastes, strips, and LED kits from pharmacies typically use very low-concentration peroxide (1–3%). They can remove surface staining and maintain results, but will not dramatically change intrinsic tooth colour. Results are modest — 1–3 shades at most.

Charcoal products are largely ineffective and can be abrasive to enamel. They are not recommended by dental professionals.

Professional Take-Home Kits

Custom-fitted whitening trays made by your dentist, combined with professional-grade gel (10–22% carbamide peroxide), deliver significantly better results than shop-bought kits. Worn for 1–2 hours daily or overnight for 2–3 weeks, they can lighten teeth by 4–6 shades. Results are gradual and even.

At Dr. Cem Smile Design, our take-home kits range from €100–€180 and include custom trays that last for years.

In-Office Professional Whitening

Professional whitening in our clinic uses a high-concentration peroxide gel (35–40%) activated by a specialist LED or laser light source. A single 60–90 minute session can lighten teeth by 6–8 shades. Results are immediate and dramatic.

The procedure:

Gums are protected with a barrier gel
Whitening gel is applied to teeth in multiple rounds
LED light activates the gel and accelerates the reaction
Teeth are polished and sensitivity gel applied

Our in-office whitening costs €200–€350, compared to £500–£900 in the UK.

Is Whitening Safe?

Professional whitening is clinically proven safe when performed correctly. The main side effect is temporary sensitivity — your teeth may feel sharp or tingly for 24–48 hours after treatment. This resolves on its own. We manage this by using desensitising agents before and after treatment, and customising concentration for sensitive patients.

Whitening does not damage enamel when done professionally and does not affect crowns, veneers, or composite restorations — which is important to know, as these cannot be whitened and need to be matched to your new tooth shade afterward.

How Long Do Results Last?

With professional whitening, results typically last 12–24 months, depending on your diet and habits. Coffee, tea, red wine, and smoking will shorten the results. Touch-up with a home kit every 6–12 months is the most effective long-term strategy.

Whitening vs. Veneers — Which Do You Need?

If your teeth are well-shaped and aligned but simply discoloured, whitening alone may achieve your goal. If you also have chips, gaps, worn edges, or shape issues, veneers will address everything at once. Many patients combine both: whitening first to find their ideal shade, then matching veneers to that shade.