Teeth Whitening: How It Works, Who It Suits & What to Expect

Why Do Teeth Discolour in the First Place?

Before talking about whitening, it helps to understand why teeth change colour. There are two main types of staining:

• Extrinsic stains: These build up on the surface of the tooth enamel from coffee, tea, tobacco, and certain foods. These can often be improved with cleaning and whitening.
• Intrinsic stains: These are within the dentine itself, caused by factors such as certain antibiotics taken in childhood, dental fluorosis, or an old tooth injury. These are harder to whiten and require a more personalised assessment.

That's why the first step is identifying which type of staining you have — something your dentist can determine with a straightforward examination.

How Does Teeth Whitening Work?

Whitening agents contain oxidising compounds that penetrate the enamel layer and break down the coloured stain molecules. The result: the enamel appears lighter. The process typically involves two stages:

1. Preparation: Removing plaque and tartar first — this matters because whitening on unclean teeth produces uneven results. You may want to book a dental cleaning before your whitening session.
2. Application: Your dentist applies the whitening agent to the teeth. Some systems use a light to accelerate the reaction. Treatment time varies depending on the system used.

To find out more about our teeth whitening service, visit the dedicated page.

Who Is a Good Candidate — and Who Isn't?

Whitening isn't suitable for every situation. Here are the key factors your dentist will consider:

• Good candidates: Healthy teeth that have yellowed or changed colour due to extrinsic staining or natural ageing.
• Not suitable, or requires further assessment: Multiple cosmetic fillings or crowns in the front area (whitening does not change the colour of composite resin or zirconia); severe tooth sensitivity; untreated decay; or active gum inflammation.
• Pregnant or breastfeeding patients: Whitening is not recommended during this period.

If your teeth need veneers or a more comprehensive cosmetic solution, zirconia crowns and a Hollywood Smile may be more appropriate. Not sure which option suits you? Try our quiz: Do I need braces, veneers, or whitening?

What to Expect After a Whitening Session

After your session, some things are normal and others are worth keeping in mind:

• Temporary sensitivity: It's common to experience sensitivity to hot and cold for a few days. This is normal and temporary for most people.
• Results aren't permanent: How long the result lasts depends on your daily habits — coffee, tea, and tobacco speed up re-staining.
• The first 48 hours: Your teeth are more susceptible to staining during this window, so it's best to avoid strongly pigmented foods and drinks.
• Ongoing maintenance: Regular professional cleaning helps preserve your results and slows down re-staining.

⚠️ If you experience sharp pain in your teeth or gums, or notice significant swelling or redness after your session, contact your dentist promptly — don't delay.

In-Clinic Whitening vs. At-Home Products: What's the Difference?

The market is full of at-home whitening products, but there are real differences between these and what a dentist can do:

• In-clinic treatment: Higher concentration of active agent, more precise application, and protection of the gums and surrounding tissues throughout the session. Results are faster and more even.
• At-home products (toothpastes, strips): Lower concentration — these may produce a modest improvement in surface staining, but won't match the results of a professional session.
• Dentist-prescribed home trays: A middle ground — your dentist creates custom-fitted trays and provides a suitable whitening agent for you to use at home under their guidance.

In short: at-home products are not a substitute for a professional session, but they can help maintain your results afterwards.

Before You Book: Questions to Ask Your Dentist

When you come in for a consultation, these questions will help you make the right decision:

• What type of staining do I have, and will whitening give me a good result?
• Are my teeth, nerves, and gum tissue ready for whitening?
• How many sessions will I need, and when can I expect to see a difference?
• What steps should I take to prepare before the session?
• If I have existing fillings or crowns at the front, how will the whitened teeth look alongside them?

Ready to book a consultation? Book your appointment online or get in touch with us on WhatsApp.