Teeth Whitening Knowledge 2

Question 1

Which chemical compound is the primary active ingredient in most professional teeth whitening gels?

Accepted Answer

Hydrogen peroxide

Answer

Hydrogen peroxide is the active bleaching agent in most professional whitening gels, oxidizing stain molecules within enamel.

Question 2

What is the typical concentration range of carbamide peroxide found in over-the-counter whitening strips?

Accepted Answer

10–22%

Answer

OTC whitening strips generally contain 10–22% carbamide peroxide, which is lower than professional in-office concentrations.

Question 3

Teeth whitening primarily works on which layer of the tooth?

Accepted Answer

Enamel

Answer

Whitening agents penetrate the enamel to oxidize chromogens, although they can also affect underlying dentin to some extent.

Question 4

Which type of tooth discoloration is generally considered most responsive to bleaching treatment?

Accepted Answer

Extrinsic yellow stains from food and drink

Answer

Extrinsic yellow stains caused by dietary chromogens respond best to whitening because they sit at or near the enamel surface.

Question 5

How does light or laser activation help in professional in-office whitening?

Accepted Answer

It accelerates the decomposition of peroxide to release more oxygen radicals

Answer

Light energy accelerates the breakdown of hydrogen peroxide into free radicals, which speeds up the oxidation of stain molecules.

Teeth Whitening Practice Test