Endodontics · single question
The principal/active component of mineral trioxide aggregate (MTA) is based on which element/compound?
Show answer and explanation
Correct answer: A. Calcium (calcium silicates)
- A. Correct. MTA is a calcium-silicate cement (derived from Portland cement) — tricalcium/dicalcium silicate and calcium oxide, with a radiopacifier (e.g., bismuth oxide). It sets to form calcium hydroxide, giving its biocompatible, sealing properties.
- B. Zinc oxide is the basis of ZOE/IRM, not MTA.
- C. Sodium fluoride is not the active MTA component.
- D. Iron oxide is a pigment, not the active MTA component.