Which of the following best describes the mechanism of action of MTA?

The correct choice identifies the mechanism of action of Mineral Trioxide Aggregate (MTA) as promoting hard tissue formation. MTA is a bioceramic material often used in dental procedures, particularly in endodontics and pulp therapy, due to its bioactive properties.

When MTA is applied in dental treatments, it stimulates the formation of a mineralized tissue, which includes hard tissue like dentin. This is vital in procedures such as pulp capping and apexification, where the goal is to protect the dental pulp and encourage the repair and regeneration of dental tissues. The composition of MTA, which includes calcium silicate, is key to its ability to engage with the surrounding biological tissues, promoting the formation of hydroxylapatite and consequently enhancing hard tissue regeneration.

While MTA also possesses some antibacterial properties and can have effects on inflammation, its predominant and well-documented mechanism is its ability to promote hard tissue formation, making it an essential material in restorative dentistry.