How does professional teeth whitening work?
Clinically reviewed by Dr Kuldip Gakhal · Principal Dentist · 7 October 2026
Professional whitening uses bleaching gel to lighten natural teeth after a dentist assesses suitability. Home treatment usually involves fitted trays and an individual gel-use plan; some methods are provided in the practice. Timings and results vary, and existing crowns, veneers or fillings do not whiten.
Start with assessment, not a standard timetable
Your dentist checks dental health, discusses the result you hope for and decides whether whitening is appropriate. UK whitening requires a registered dentist's assessment and prescription. You can decide against cosmetic treatment.[2]
Agree the method and instructions
For supervised home whitening, the dental team provides fitted trays and instructions for the prescribed gel. Other methods are carried out in the practice. The method and treatment time depend on your teeth and plan; overnight use and a two-week course are not universal instructions.[1][3]
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Cadbury Dental. ESTD 1905. Professional whitening Your plan with the dental team 1 Assess: Check dental health and discuss your goals. 2 Plan: Agree suitable treatment and written instructions. 3 Review: Check comfort, shade and next steps. Follow your own dentist's plan. Results and timings vary.
Plan around crowns, veneers and fillings
Whitening changes natural teeth, not existing restorations. A visible crown or filling may look different beside newly lightened teeth. Discuss this before treatment; do not assume healthy dental work must be replaced.[4]
Review comfort and expectations
Shade change varies and is not permanent. The team should explain side effects and any future maintenance. For sensitivity, gum irritation and suitability questions, see our whitening safety guide.[3][1]
Whitening questions at Cadbury Dental
Cadbury Dental Practice is in Bournville, Birmingham.[5] Read about teeth whitening at Cadbury Dental to explore the service before enquiring.
Cosmetic & whitening: your questions on this topic
Does everyone need two weeks of whitening?
No. Duration and daily wear depend on the method and your own prescribed plan. Follow your dental team's instructions rather than a generic timetable.
Can whitening guarantee a particular shade?
No. Teeth respond differently and existing restorations keep their colour. Discuss realistic expectations before deciding.
Is buying an online kit the same as supervised whitening?
No. It does not provide a dental assessment or a personalised prescription. The NHS warns that home kits can harm teeth and gums; discuss suitable options with a dentist.
Sources
- [1]Teeth whitening — NHS. Checked 7 October 2026.
- [2]Tooth whitening and illegal practice — General Dental Council. Checked 7 October 2026.
- [3]Tooth whitening — Oral Health Foundation. Checked 7 October 2026.
- [4]Tooth Whitening: information for adult patients — Leeds Teaching Hospitals NHS Trust. Checked 7 October 2026.
- [5]Cadbury Dental Practice: map and contact details — Care Quality Commission. Checked 7 October 2026.
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