Teeth whitening, honestly compared

Whitening is the most-asked-about cosmetic treatment in our practice, and also the most confusing. The shelves are full of strips, pens, LED gadgets and charcoal powders, all promising Hollywood results. Here is what each option really delivers.

How whitening works

Real whitening uses a peroxide gel, either hydrogen peroxide or carbamide peroxide, which breaks down stain molecules inside the enamel. The strength of the gel and how long it stays in contact with your teeth determine the result. Anything without peroxide, including charcoal and most whitening toothpastes, only removes surface stains. It cannot change the colour of the tooth itself.

It is also worth knowing that whitening only works on natural enamel. Crowns, veneers and tooth-coloured fillings stay the same shade, so if you have visible restorations at the front, talk to your dentist before you start.

Your options, side by side

• Whitening strips ($40–$60): low-strength gel, uneven contact with curved teeth. Modest results, fine for a mild touch-up.
• Custom take-home trays ($295 at Lumen): trays made from a scan of your teeth, with professional gel. Three to six shades lighter over two weeks.
• In-office whitening ($495 at Lumen): high-strength gel with gums protected, done in about 90 minutes. Up to eight shades in a single visit.
• Charcoal powders: abrasive and not recommended. They can scratch enamel and make teeth look more yellow over time.

The best whitening result is the one that still looks natural when you are not smiling for a camera.

Sensitivity, and how to avoid it

Temporary sensitivity is the most common side effect, and it usually fades within 48 hours. To keep it down, brush with a sensitivity toothpaste containing potassium nitrate for two weeks before you start, avoid very hot and cold drinks for a day after each session, and space out home treatments if your teeth start to twinge.

Whitening is not suitable for everyone. If you have untreated decay, receding gums or are pregnant, we will recommend waiting. That is one reason a check-up first makes sense: whitening over a cavity is a fast route to real discomfort.

To keep results longer, rinse with water after coffee, tea or red wine, use a straw for iced drinks and top up with your trays for one or two nights every few months. Most patients keep a bright, natural shade for years this way, without ever needing a second in-office session.