Teeth Whitening Teeth Whitening 2 — Questions and Answers
Question 1: Which ingredient in whitening toothpaste physically scrubs away surface stains?
- Hydrogen peroxide
- Sodium fluoride
- Hydrated silica (Correct answer)
- Sodium lauryl sulfate
Correct answer: Hydrated silica
Hydrated silica is a mild abrasive added to whitening toothpastes to mechanically remove surface stains.
Question 2: A patient has tetracycline-stained teeth. Which whitening approach is most likely to produce results?
- Single in-office session
- Over-the-counter strips used for 2 weeks
- Prolonged at-home bleaching over several months (Correct answer)
- Whitening toothpaste used daily
Correct answer: Prolonged at-home bleaching over several months
Tetracycline stains are intrinsic and stubborn, typically requiring prolonged at-home bleaching over weeks to months for noticeable improvement.
Question 3: What is the primary role of a light or laser during an in-office whitening procedure?
- It directly bleaches the enamel
- It kills bacteria causing discoloration
- It activates or accelerates the bleaching gel (Correct answer)
- It hardens the protective gel on gums
Correct answer: It activates or accelerates the bleaching gel
The light or laser is used to activate and accelerate the breakdown of hydrogen peroxide in the whitening gel, not to bleach directly.
Question 4: Which of the following foods is MOST likely to re-stain teeth immediately after whitening?
- White rice
- Blueberries (Correct answer)
- Sliced turkey
- Cauliflower
Correct answer: Blueberries
Blueberries contain dark pigments (chromogens) that can penetrate open enamel pores right after whitening, causing re-staining.
Question 5: Carbamide peroxide breaks down in the mouth into hydrogen peroxide and which other compound?
- Sodium bicarbonate
- Urea (Correct answer)
- Calcium hydroxide
- Fluoride
Correct answer: Urea
Carbamide peroxide decomposes into hydrogen peroxide (the active bleaching agent) and urea.
Question 6: Why are custom-fitted whitening trays considered superior to one-size-fits-all strips for even whitening?
- They contain a stronger peroxide formula
- They prevent saliva dilution and ensure full tooth coverage (Correct answer)
- They are heated to open enamel pores wider
- They use UV light automatically
Correct answer: They prevent saliva dilution and ensure full tooth coverage
Custom trays conform precisely to teeth, preventing saliva from diluting the gel and ensuring consistent contact across all tooth surfaces.
Question 7: A patient reports sharp sensitivity during whitening. The dentist's FIRST recommendation should be to:
- Discontinue whitening permanently
- Switch to a higher peroxide concentration
- Use a desensitizing toothpaste and reduce treatment frequency (Correct answer)
- Apply whitening gel directly to gums
Correct answer: Use a desensitizing toothpaste and reduce treatment frequency
Sensitivity is common and manageable; dentists typically advise potassium nitrate desensitizers and spacing out treatments rather than stopping entirely.
Teeth Whitening Teeth Whitening 2
Which ingredient in whitening toothpaste physically scrubs away surface stains?