Understanding teeth whitening.
Possibilities and limits.
Not all discolouration is the same.
Natural tooth colour comes from the interaction of enamel and dentine. Surface deposits can also stain teeth. Cleaning removes these deposits; whitening acts on coloured compounds within the tooth.
Changing coloured compounds chemically.
Whitening gels usually contain peroxides. These can enter the hard tooth tissues and change coloured molecules through oxidation. How noticeable the whitening is depends partly on the type of discolouration.
The examination comes first.
Before whitening, the examination includes checking for decay, leaking restorations and gum problems. Some findings may require preliminary treatment. Sensitive teeth and individual circumstances are taken into account when planning.
Supervised and individual.
Whitening can take place in the practice or at home using trays under a dentist’s guidance. Gum protection, gel quantity and application time depend on the method. Extending applications yourself can increase the risk of irritation.
Fillings do not whiten.
Whitening changes the colour of natural tooth tissue. Fillings, crowns and veneers do not whiten with it. This can make differences in shade noticeable. Whether anything might need adjusting later is part of the initial discussion.
Results remain individual.
Temporary sensitivity and gum irritation can occur. If there is severe pain, the application is stopped and dental advice sought. The shade and duration of whitening vary from person to person; a specific brightness cannot be promised.
Get advice for your teeth.
Suitable treatment options can only be assessed after a dental examination and a personal discussion.
Medical sources
Editorial source check: 2 October 2026.