It involves the use of whitening products to change the natural colour of teeth. This is an elective procedure, meaning it is chosen by the patient rather than required for medical reasons.

How Teeth Whitening Works

Teeth whitening involves applying a professional whitening gel to the surface of the teeth. The gel acts on stains within the outer layer of the tooth (enamel) and can change the overall colour of the natural teeth. This process focuses on reducing discolouration that has built up over time from food, drinks, or other factors.

Only natural teeth respond to whitening. Dental restorations such as crowns, veneers, or fillings do not change colour and may need to be checked if a difference in shade is noticed after treatment.

Teeth whitening can be done in two main ways. The first is in-chair whitening, carried out in the dental clinic under professional supervision. The second is at-home whitening, where the dentist provides fitted mouthpieces and a whitening gel for the patient to use at home under guidance.

Both options work in similar ways, but the time, strength, and number of sessions can vary. The dentist will explain the process and discuss which approach may be most suitable for your situation.

In-Chair Whitening

In-chair whitening is carried out entirely in the dental clinic under professional supervision. During the appointment, a whitening gel is applied to the teeth while the gums and lips are covered with protective material. A special light may be used to support the process. The session usually takes about one to one and a half hours, depending on the system used.

This option may be considered by patients who prefer treatment to be completed in a single visit. Sensitivity to temperature or sweet foods can occur afterwards, and some teeth may respond differently to whitening. Because restorations such as fillings or veneers do not change colour, they may appear more noticeable after treatment. The effect is not permanent, and maintenance or occasional follow-up whitening may be needed.

Possible Risks and Side Effects

As with any dental procedure, teeth whitening may involve some side effects. These should be understood before starting treatment.
The most common issue is tooth sensitivity, which may occur during or after whitening. This sensitivity often settles once treatment stops. Mild gum or cheek irritation can happen if the whitening gel touches the soft tissues. Some teeth may respond differently, especially if there are fillings, crowns, or veneers, as these materials do not change colour.

If gums have receded or roots are exposed, the teeth may feel more sensitive. Whitening too often or using products incorrectly can damage the outer layer of the teeth. For this reason, it should always be carried out under professional supervision. The dentist will check progress and may recommend pausing if discomfort occurs.

Preparing for Whitening

Before starting whitening, the mouth should be clean and healthy. A professional clean helps remove surface build-up so the whitening works more evenly. Any tooth decay or gum concerns should be managed first. The dentist will discuss what shade change is realistic and how to use any trays or gels correctly. Guidance will also be given on managing sensitivity if it occurs.

Proper preparation helps the process to be carried out safely and comfortably.

How Long Whitening Effects Last

Whitening does not last forever. Over time, colour can gradually fade due to eating and drinking habits, such as tea, coffee, or red wine, as well as natural ageing. How long the result lasts depends on each person’s care and habits.

Some patients choose to maintain their results with occasional whitening at home using trays provided by their dentist. This should only be done under dental supervision.

Caring for Whitened Teeth

To help care for your teeth after whitening:

Brush twice daily with fluoride toothpaste.
Clean between teeth each day using floss or other cleaning aids.
Limit food and drinks that can cause staining, such as tea, coffee, and red wine.
Rinse or brush after eating or drinking anything with a strong colour.
Use a soft toothbrush and gentle toothpaste to protect the enamel.
Continue with regular dental check-ups for monitoring and maintenance.
If advised, you may use home whitening trays occasionally.

Following these steps helps support ongoing oral cleanliness and the appearance achieved after whitening.

Common Misconceptions

Whitening does not change the colour of existing fillings, crowns, or veneers.
Stronger gels do not always give better results and can increase the chance of side effects.
Whitening results vary for each patient; not all teeth respond in the same way.
Over-the-counter whitening kits can pose risks and should not be used without dental advice.

Understanding these points helps patients make informed, safe decisions about whitening.