Whitening: The UK Rules

What the Regulations Say

UK law treats tooth whitening as dentistry. So only people on the General Dental Council (GDC) register may provide it. A dentist has to examine you and prescribe the treatment. Once prescribed, a registered hygienist or therapist may carry it out, but never a beautician, a salon worker or a kiosk attendant.

The products are controlled too. Gels that contain or release more than 0.1% and up to 6% hydrogen peroxide are sold only to dental professionals. A dentist carries out, or directly supervises, the first application of a course, and you carry on at home after that. Anything over 6% is banned for cosmetic use. For anyone under 18, gels above 0.1% are off limits unless they're being used solely to treat or prevent disease.

Many dental gels are labelled in carbamide peroxide rather than hydrogen peroxide. Carbamide breaks down to release roughly a third of its strength as hydrogen peroxide, so a 16% carbamide gel releases a little under 6%.

Where Shop Kits Fit In

Strips, pens, LED gadgets and whitening toothpastes sold in chemists and online are capped at 0.1% hydrogen peroxide. At that level they can lift some surface stain, but they can't do much to the colour inside the tooth. They're legal and mostly harmless; they just don't do what the packaging suggests.

Why Salon Whitening Is a Gamble

Whitening by anyone who isn't GDC registered is illegal, whether it's offered in a salon, a spa, a pop-up stand or at a house party. The GDC prosecutes people for it. Some providers try to stay inside the law by handing you a tray to put in yourself. That doesn't make it legal, and it doesn't make it safe.

• Nobody checks your mouth. Whitening over decay, a cracked tooth or receding gums can be very painful and can hide a problem that needs treating.
• The gel may be illegal or useless. Some products are far too weak to work. Others use chlorine dioxide, sold as "peroxide-free", which can roughen and weaken enamel.
• Loose trays leak. Gel spreading onto the gums can burn them.
• No one is accountable. If something goes wrong, there's no registered clinician to put it right.

You can look up any dentist, hygienist or therapist on the GDC's online register in under a minute. If the person offering whitening isn't there, walk away.

Is Professional Whitening Safe?

Yes, with a regulated gel and a dentist overseeing it. Peroxide whitening has a long track record in dental practice. Used as directed, it doesn't strip or thin enamel. The common side effect is sensitivity to cold while you're whitening, which fades once you stop. Because the trays are made for your mouth, gel stays on the teeth rather than the gums.

There are times we'd say no or not yet. We don't whiten under-18s for cosmetic reasons, or anyone who is pregnant or breastfeeding, as a precaution. Decay, cracked teeth and gum disease are treated first. If your teeth are already sensitive, we can adjust the routine, as our whitening sensitivity guide describes.

How We Whiten in Hamilton, Step by Step

1. Examination. A dentist checks for decay, cracks and gum problems and notes fillings, crowns or veneers on your front teeth, since none of those will lighten.
2. Scan. A quick iTero Lumina digital scan instead of impression putty. Your trays are made from it.
3. Fitting. On the day the trays are ready, we try them in, demonstrate how much gel goes in each and how long they stay in, and note your starting shade.
4. Home whitening. Typically two to three weeks of daily wear with Boutique gel.
5. Review. We compare the new shade with the old, check your gums and talk about keeping the result.

The gel works by releasing oxygen that seeps into the enamel and breaks up the coloured molecules that make teeth look darker. Yellow-toned teeth respond fastest. Grey or brown staining is slower and less predictable.

What Whitening Won't Change

Nothing artificial lightens: fillings, crowns, veneers and bonding stay as they are. Where those are on show, we'll tell you beforehand whether they're likely to stand out afterwards and plan for replacing them if needed. New bonding or veneers should come after whitening, so they're made to match the lighter teeth.

Some staining is stubborn: a tooth that darkened after an injury or a root filling, or deep banding from certain antibiotics taken in childhood. We'd rather tell you honestly at the consultation than oversell. Every mouth responds differently, ² and we'd rather agree a target shade with you than quote a number of shades.

Keeping the Colour

Expect the result to hold for at least a year for most people, longer if you go easy on staining food, drink and tobacco. You keep your trays, so a few nights with top-up gel brings the shade back. A glass of water after a cuppa or a glass of red, staying off cigarettes and keeping your hygiene visits all help. There's more in our guide to keeping teeth white.

What It Costs in Hamilton

Boutique home whitening at Hamilton Smile Studios is £350, or £315 for dental plan members. ¹ That includes the examination, the scan, your custom trays, the gel and the review. If you're having Invisalign or a bonding package with us, whitening is already part of it.

There's no charge for the whitening consultation itself; a £40 deposit secures the slot and comes back to you within 7 days of attending. If you'd like to ask something first, send a message on WhatsApp to 07904 504756. The whitening page has the details.

Questions

This guide is general information, not a diagnosis. A dentist needs to examine you to say what is right for your teeth.