Whitening is one of the most requested cosmetic treatments in dentistry, but it is also one of the most misunderstood. Here's an honest look at what it can and cannot achieve, and how to whiten safely.
How whitening actually works
Professional whitening gels contain hydrogen peroxide or carbamide peroxide, which break down stain molecules inside the enamel and dentine. The tooth structure isn't removed or damaged — it's the stains within it that fade. That's why properly done whitening does not weaken teeth.
What whitening can do
Professional whitening effectively lifts surface stains and internal discolouration from coffee, tea, red wine, tobacco, curry, dark berries and normal ageing. Results are noticeable within a few sessions and, with good habits, can last months to years before a top-up is needed.
What whitening cannot do
Whitening does not change the colour of crowns, veneers, composite fillings or bridges — they stay the shade they were made. It also cannot fix deep intrinsic stains (like tetracycline staining from childhood antibiotics) — those cases usually need masking, bonding or veneers. If your front teeth have visible fillings, those may need to be replaced after whitening to match your new shade.
In-office vs at-home kits
Professional in-office whitening uses higher-strength, carefully monitored gels for faster, safer results — often a full shade change in a single visit. Custom-fitted home trays supplied by a dentist are also very effective and let you top up over time. Over-the-counter strips and generic mouth-guard kits are gentler and slower, and are more likely to cause uneven results, gum irritation or sensitivity if used incorrectly.
Managing sensitivity
Some short-term sensitivity to cold is common during whitening and usually settles within a few days. Using a toothpaste for sensitive teeth for two weeks before and during treatment, and taking breaks between sessions, keeps most people comfortable. Persistent pain isn't normal — pause and check in with us.
Keeping your results
Rinse with water after coffee, tea and red wine. Use a straw for very dark drinks. Don't smoke — nothing stains teeth faster. And schedule a short top-up whitening session every 6–12 months if you like the brightest possible shade.
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