After placement of MTA in the tooth, body fluids infiltrate the paste to cause setting.
During this process, calcium and hydroxide ions are released from the MTA, promoting hydroxyapatite (HA) formation on the MTA surfaces.
When HA coats the surface, it hides the underlying MTA to minimize foreign body reactions and support healing responses of the pulpal or periapical tissue.
Calcium phosphate precipitated crystals scattered on the hydrated tricalcium silicate cement surface1.
High magnification image of the calcium phosphate crystals1.
Hydroxyapatite forms to ensure BioActive sealing.
Courtesy of Zafer C. Cehreli, DDS, PhD