What is the role of calcium hydroxide in endodontics?

• A. Intracanal medicament with antimicrobial properties and promotion of dentin healing/hard tissue formation.
• B. A desensitizing agent used for hypersensitive teeth only.
• C. A primary resin-based sealer for obturation.
• D. A temporary filling material for coronal leakage.

Answer: (A)

Calcium hydroxide acts as an intracanal medicament with antimicrobial properties and promotes dentin healing and hard tissue formation. Its high pH around 12.5 creates an alkaline environment that disrupts bacterial membranes, inactivates endotoxins, and inhibits bacterial enzymes, helping to disinfect the root canal system between visits. This same alkaline setting stimulates mineralization processes, encouraging odontoblastic activity and hard tissue deposition, which supports healing of periapical tissues and potential formation of dentin bridge. It’s used inside the canal to reduce microbial load and promote healing, rather than to seal or desensitize. It is not a desensitizing agent for hypersensitive teeth, nor a primary resin-based sealer for obturation, nor a temporary filling material for coronal leakage.