How whitening actually works
Professional whitening uses hydrogen peroxide or carbamide peroxide gel held against the teeth in custom-made trays. The peroxide releases oxygen molecules that pass into the enamel and break apart the coloured compounds staining the tooth from within. This is the crucial distinction from whitening toothpastes and stain-removal polishing, which only address surface stains: true whitening changes the internal shade of the tooth itself.
The legal position in the UK — and why it protects you
Tooth whitening is legally classed as the practice of dentistry in the UK. Only dentists registered with the General Dental Council — or hygienists and therapists working to a dentist's prescription — may legally perform it. Beauticians, salons and kiosks offering whitening are committing a criminal offence, and the General Dental Council actively prosecutes them.
This is not professional protectionism. Peroxide strong enough to whiten can damage gums and teeth applied incorrectly, whitening fails or behaves unpredictably on crowns, veneers and fillings, and tooth discolouration can occasionally signal an underlying problem — a dying nerve, decay — that a salon will whiten over and a dentist will diagnose. EU-derived UK regulations also cap the peroxide concentration in products sold directly to the public so low that high-street kits cannot deliver meaningful change. The materials that genuinely work are only available through a dentist.
What we use at Station House
We provide professional Boutique whitening from £330: custom trays made from impressions or scans of your teeth, with prescription-strength gel you use at home, typically worn either during the day or overnight depending on the formulation we select for you. Custom trays matter — they hold the gel exactly where it should be and keep it off your gums, which is the difference between professional whitening and the ill-fitting strips and generic trays sold online.
Realistic results — what whitening can and cannot do
Most patients lighten by several shades over two to three weeks of tray wear. Yellow-toned staining responds best; grey or brown discolouration (including tetracycline staining from childhood antibiotics) responds more slowly and less completely. Whitening does not change the colour of crowns, veneers, bridges or fillings at all — if you have visible dental work, we plan around it, sometimes whitening first and then matching replacement restorations to your new shade.
A tooth that has darkened after a root canal is a special case: it can often be whitened from the inside (internal whitening), which is a different procedure — ask us rather than assuming trays will fix it.
The truth about sensitivity
Temporary sensitivity is the most common side effect — typically a cold-sensitivity or occasional short 'zing' during the whitening period, settling within a few days of finishing. It is manageable: using a desensitising toothpaste before and during treatment, reducing wear time, or taking nights off all help, and we adjust your regime rather than leaving you to suffer through it. Whitening performed correctly with custom trays does not damage enamel — the sensitivity is transient nerve irritation, not erosion.
How long results last — and keeping them
Expect the result to hold well for one to three years, depending mostly on you: tea, coffee, red wine and smoking re-stain teeth fastest. The maintenance advantage of custom trays is permanent — you keep them, and an occasional top-up with a syringe of gel (a night or two every few months) maintains the shade indefinitely for a fraction of the original cost. Regular hygienist visits (from £72) also remove the surface staining that dulls whitened teeth.
Whitening as the first step of a smile makeover
If you are considering bonding or veneers, whiten first. Composite and porcelain are colour-matched to your teeth at the time they are made and never change shade afterwards — so establishing your final tooth colour before matching restorations to it is the correct sequence. It is also the cheapest cosmetic win available: for many patients, whitening alone (from £330) delivers most of the improvement they wanted, before any drill is involved.