Why is calcium hydroxide used as a pulp capping material in primary teeth?

Calcium hydroxide is particularly valued as a pulp capping material in primary teeth primarily because it stimulates the formation of a calcified barrier. This property is crucial when the dental pulp is exposed or at risk of exposure due to decay or trauma. When applied to the affected area, calcium hydroxide promotes the activity of odontoblasts, which are the cells responsible for dentin formation. These cells respond by generating new dentin, leading to the development of a protective barrier that can help preserve the vitality of the tooth and prevent further injury or infection.

While neutral pH and non-irritating properties are beneficial qualities of calcium hydroxide, they are secondary to its direct role in facilitating tissue regeneration and repair. Additionally, the formation of odontoclast-like cells is not a desirable effect in pulp therapy; these cells are typically involved in the resorption of dentin, which is contrary to what is desired in pulp capping. Hence, it is the calcified barrier stimulation that underscores the primary benefit of calcium hydroxide use in this context.