My teeth won t whiten
Teeth may not whiten when discoloration is internal, caused by an enamel defect, or belongs to a restoration.
The short answer
Teeth may not whiten when discoloration is inside the tooth, comes from an enamel defect or medication, or belongs to a restoration rather than natural enamel.
How does peroxide whitening affect tooth discolouration?
Peroxide acts mainly on stain molecules in natural tooth structure. It cannot bleach ceramic or composite restorations, and a single dark tooth may have an internal problem.
What should I do if whitening is not working?
Stop repeating whitening applications until the cause is identified. Examination, shade comparison, cleaning, pulp testing, or a restorative option may be needed.
When should a dentist assess teeth that will not whiten?
Seek care for one darkening tooth, trauma, pain, or persistent sensitivity. Swelling, fever, pus, or trouble opening the mouth warrants prompt assessment.
What should I ask about the cause of the discolouration?
Is this surface stain, intrinsic discoloration, or a mismatched restoration, and which option preserves the most tooth structure?
Frequently asked questions
What is the main cause?
Peroxide acts mainly on stain molecules in natural tooth structure.
When should I arrange an examination?
Seek care for one darkening tooth, trauma, pain, or persistent sensitivity.
Keep reading
Who wrote this page
This library is published by Dental Nation, a licensed dental group practising in the United Arab Emirates. Pages are written and overseen by the same clinical team that treats patients in our clinics, and are held to a fixed editorial standard for safety and accuracy.
This page is patient education, not medical advice, and cannot replace an examination. Anything urgent — facial swelling, trauma, uncontrolled bleeding or severe pain — needs a dentist or emergency care now.