Endodontics · patient case with 1 question
Internal bleaching material
Scenario: Which material is used for INTERNAL (non-vital / walking) bleaching?
Question 1
Which material is used for internal bleaching?
Show answer and explanation
Correct answer: D. Sodium perborate
- A. Calcium hydroxide is an intracanal medicament and pulp-capping material; it is sometimes placed AFTER internal bleaching to counteract the acidic environment implicated in external cervical resorption, but it is not the bleaching agent.
- B. Sodium fluoride is a remineralising and anticariogenic agent with no bleaching action.
- C. Glass ionomer is a restorative and luting material — used here for the protective cervical barrier over the gutta-percha, not for bleaching.
- D. Correct. SODIUM PERBORATE, mixed with water or hydrogen peroxide and sealed into the pulp chamber, is the classic 'walking bleach' material for a discoloured endodontically treated tooth. It decomposes to release oxygen, which breaks down the chromogens from blood breakdown products in the dentinal tubules.
Note: Hydrogen peroxide and carbamide peroxide ARE bleaching agents, but they are the mainstays of EXTERNAL (vital) bleaching. Always place a cervical barrier (e.g. GIC or RMGI) over the gutta-percha before internal bleaching to prevent EXTERNAL CERVICAL RESORPTION.