Teeth Whitening Whitening Ingredients & Chemistry 2 — Questions and Answers
Question 1: What does PAP stand for in the context of newer non-peroxide whitening formulas?
- Phthalimidoperoxycaproic acid (Correct answer)
- Phenyl amino propanol
- Phosphate activated polymer
- Polyamine peroxide agent
Correct answer: Phthalimidoperoxycaproic acid
PAP (phthalimidoperoxycaproic acid) is a peroxide-free oxidizing agent used in some whitening products claimed to cause less sensitivity.
Question 2: Intrinsic tooth stains caused by tetracycline antibiotics are classified as what type of discoloration?
- Intrinsic chromogenic staining (Correct answer)
- Extrinsic surface staining
- Fluorosis banding
- Calculus-related staining
Correct answer: Intrinsic chromogenic staining
Tetracycline staining is a classic intrinsic discoloration where the antibiotic incorporates into the developing dentin during tooth formation.
Question 3: Why is a higher concentration of peroxide NOT always more effective for at-home whitening trays?
- It breaks down too quickly before adequate penetration occurs (Correct answer)
- It permanently hardens enamel
- It removes fluoride ions from the tooth
- It requires UV light to activate
Correct answer: It breaks down too quickly before adequate penetration occurs
Very high concentrations decompose rapidly on contact with saliva and oral tissues, leaving less active peroxide available to penetrate and bleach.
Question 4: Titanium dioxide is included in some whitening products mainly for what purpose?
- To provide immediate optical whitening via light reflection (Correct answer)
- To accelerate peroxide decomposition
- To bind stain molecules to enamel
- To lower the pH of the gel
Correct answer: To provide immediate optical whitening via light reflection
Titanium dioxide is an opacifying white pigment that gives an instant visual whitening effect through light scattering, but it does not bleach the tooth.
Question 5: What pH range do professional whitening gels typically maintain to balance efficacy and enamel safety?
- 5.5–7.0 (Correct answer)
- 3.0–4.5
- 7.5–9.0
- 1.0–2.5
Correct answer: 5.5–7.0
Professional gels are formulated around pH 5.5–7.0 to keep peroxide chemically active while minimizing acidic erosion of enamel.
Question 6: Which naturally occurring compound gives coffee, tea, and red wine their staining power on teeth?
- Tannins (polyphenols) (Correct answer)
- Caffeine alkaloids
- Acetic acid esters
- Lactic acid bacteria
Correct answer: Tannins (polyphenols)
Tannins are polyphenolic compounds that bind to the pellicle on enamel and form stable colored complexes that appear as extrinsic stains.
Teeth Whitening Whitening Ingredients & Chemistry 2
What does PAP stand for in the context of newer non-peroxide whitening formulas?