Which material is acidic and may cause pulpal irritation in deep cavities?

Zinc phosphate cement is recognized for its acidic nature, which can lead to pulpal irritation, particularly in cases where it is placed in deep cavities without adequate insulation. The acidic environment created by this cement can potentially irritate the dental pulp, especially if there is insufficient dentin between the cement and the pulp.

It's important to use suitable liners or bases to protect the pulp when employing zinc phosphate cement in deep cavities. This ensures that the acidic properties do not compromise the health of the underlying pulp tissue. Other materials mentioned, such as calcium hydroxide paste and glass ionomer cement, are typically more biocompatible and may even serve protective roles for the pulp due to their neutral or basic properties. Zinc polycarboxylate cement, while also less acidic than zinc phosphate, offers some protective qualities as well.

Understanding the material properties and their interaction with tooth structures is vital in clinical dental practice, guiding the choice between restorative options and ensuring patient safety and comfort.