Opalescence ingredients
Whitening gels commonly use carbamide peroxide or hydrogen peroxide, with sensitivity depending on concentration and contact with tissues.
The short answer
Whitening gels commonly contain carbamide peroxide or hydrogen peroxide, plus a gel base and other formulation ingredients; the risks depend on the product, concentration, contact time, and your teeth and gums.
Which ingredients affect whitening gel safety for you?
Peroxide breaks down into reactive oxygen compounds that diffuse through enamel and dentin and alter coloured stain molecules.
How do carbamide and hydrogen peroxide differ?
Carbamide peroxide releases hydrogen peroxide more gradually, while hydrogen peroxide acts directly in the gel during contact with the tooth.
Sensitivity can occur when peroxide reaches dentinal tubules, and gum irritation can occur when gel contacts soft tissue.
How can you use whitening ingredients safely?
Check the exact ingredient list and concentration, use only the supplied amount and contact time, and keep gel off the gums.
Do not swallow gel or place it on teeth with untreated decay, cracks, exposed roots, or inflamed gums without dental guidance.
When should sensitivity or gum changes need care?
Seek an examination for persistent sensitivity, gum whitening or burning, uneven darkening, or pain in one tooth.
Urgent assessment is needed for facial swelling, severe pain, or a reaction involving breathing or swallowing.
What should you ask about ingredients and your whitening goal?
Ask whether the ingredient and concentration fit your enamel, dentin, gums, existing restorations, and whitening goal.
Ask how to adjust contact time, manage sensitivity, and avoid whitening a tooth whose colour change comes from disease.
Frequently asked questions
Is carbamide peroxide the same as hydrogen peroxide?
No. Carbamide peroxide breaks down and releases hydrogen peroxide gradually, while hydrogen peroxide is already the active peroxide.
Why do whitening gels cause sensitivity?
Peroxide can diffuse through enamel and dentin and temporarily stimulate sensitive tooth structures.
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.