Teeth Whitening Professional In-Office Whitening Procedures 2 — Questions and Answers
Question 1: What does 'power bleaching' refer to in dentistry?
- In-office whitening using high-concentration peroxide, often with light or heat activation (Correct answer)
- A home kit with extra-strength strips
- An ultrasonic device that blasts stains off enamel
- A laser that vaporizes stain molecules
Correct answer: In-office whitening using high-concentration peroxide, often with light or heat activation
Power bleaching is the clinical term for chairside whitening using high-concentration gel accelerated by a light or heat source under professional supervision.
Question 2: Why might a dentist recommend internal (non-vital) bleaching for a single darkened tooth?
- The tooth has had a root canal, and the stain originates inside the pulp chamber (Correct answer)
- Internal bleaching is faster than external for all cases
- The patient has severe gum recession around that tooth
- Surface whitening is contraindicated if a crown is present
Correct answer: The tooth has had a root canal, and the stain originates inside the pulp chamber
Non-vital (internally darkened) teeth are bleached from inside the pulp chamber after root canal treatment because the stain source is within the tooth.
Question 3: The 'walking bleach' technique involves placing which agent inside the pulp chamber between appointments?
- Sodium perborate mixed with water or hydrogen peroxide (Correct answer)
- Calcium hydroxide paste
- Zinc oxide eugenol cement
- Chlorhexidine gel
Correct answer: Sodium perborate mixed with water or hydrogen peroxide
Sodium perborate (with or without hydrogen peroxide) is sealed inside the pulp chamber and slowly releases oxygen to bleach the tooth from within between visits.
Question 4: After in-office whitening, the dentist typically advises the patient to avoid colored foods and drinks for how long?
- 24–48 hours (Correct answer)
- 5–10 minutes
- One week
- One month
Correct answer: 24–48 hours
The enamel surface is more porous and susceptible to re-staining immediately after whitening, so the 24–48-hour 'white diet' minimizes early chromogen uptake.
Question 5: Which patient condition is an absolute contraindication for in-office whitening?
- Untreated active caries (cavities) (Correct answer)
- Mild enamel fluorosis
- Coffee and tea staining
- Recent dental crown placement
Correct answer: Untreated active caries (cavities)
Active caries must be treated before whitening because peroxide can penetrate through decayed enamel directly to the pulp, causing irreversible pulp damage.
Question 6: What is 'rebound' in the context of teeth whitening?
- A slight darkening of teeth in the weeks following whitening as enamel rehydrates (Correct answer)
- The bounce-back of peroxide bubbles during application
- A patient's allergic reaction to whitening gel
- The reactivation of old stains by acidic foods
Correct answer: A slight darkening of teeth in the weeks following whitening as enamel rehydrates
Rebound refers to a mild reversal toward a slightly darker shade as the dehydrated, whitened enamel rehydrates and stabilizes in the weeks after treatment.
Teeth Whitening Professional In-Office Whitening Procedures 2
What does 'power bleaching' refer to in dentistry?