Teeth Whitening Whitening Ingredients & Chemistry 1

Question 1

What is the active bleaching agent in most professional teeth whitening gels?

Accepted Answer

Hydrogen peroxide

Answer

Hydrogen peroxide is the primary active bleaching agent that penetrates enamel to oxidize and break apart stain molecules.

Question 2

Carbamide peroxide breaks down into which two compounds when applied to teeth?

Accepted Answer

Hydrogen peroxide and urea

Answer

Carbamide peroxide decomposes into hydrogen peroxide (the active bleaching agent) and urea, which acts as a stabilizer.

Question 3

A 35% carbamide peroxide gel is approximately equivalent in whitening strength to what percentage of hydrogen peroxide?

Accepted Answer

10–12%

Answer

Carbamide peroxide is roughly one-third as potent as hydrogen peroxide, so 35% carbamide ≈ 10–12% hydrogen peroxide.

Question 4

Which ingredient is commonly added to whitening gels to reduce tooth sensitivity during treatment?

Accepted Answer

Potassium nitrate

Answer

Potassium nitrate depolarizes nerve fibers in the dentinal tubules, reducing the pain signal associated with whitening sensitivity.

Question 5

Fluoride is often included in whitening trays or post-whitening treatments primarily to do what?

Accepted Answer

Remineralize enamel and reduce sensitivity

Answer

Fluoride helps remineralize the enamel surface temporarily weakened during bleaching and reduces post-treatment sensitivity.

Teeth Whitening Practice Test