Calcium hydroxide can be used as an indirect pulp cap in which situation?

Calcium hydroxide is commonly used as an indirect pulp cap in scenarios where there is a near pulp exposure. This treatment is designed to protect the pulp and promote healing while allowing for the continued formation of dentin. When the remaining dentin is very thin but intact, applying calcium hydroxide can help stimulate the pulp to produce reparative dentin, thus serving to protect the pulp from potential infection or injury.

The choice of using calcium hydroxide in the presence of a near pulp exposure is based on its properties, including its ability to stimulate mineralization and its antimicrobial effects. It helps create a conducive environment for pulp vitality, making it an ideal choice when there's a risk of exposure but the pulp has not yet been compromised.

Other situations mentioned do not align with the optimal use of calcium hydroxide for indirect pulp capping. For instance, applying it when there is complete dentin present may not be necessary as the pulp is already shielded. In small carious lesions, a simpler and less invasive technique would typically be sufficient. Finally, in cases without any exposure, the need for a pulp cap is unnecessary since there is no risk to the pulp, making it inappropriate to utilize calcium hydroxide in such circumstances.