Which materials are typically used as liners or bases in deep cavities?

Calcium hydroxide and glass ionomer are commonly used as liners or bases in deep cavities due to their specific properties that promote dental health and support tooth structure. Calcium hydroxide is a material known for its pulp-capping abilities; it stimulates dentin formation and provides a biological barrier to protect the pulp from thermal, chemical, or bacterial irritation. Its high pH also creates a favorable environment for healing.

Glass ionomer, on the other hand, not only provides a seal against microleakage but also has the advantage of releasing fluoride, which can help in remineralizing adjacent tooth structure and providing resistance against secondary caries. When used together, these materials create a synergistic effect, where calcium hydroxide offers pulp protection while glass ionomer supports the restoration of structural integrity and enhances the longevity of the restoration.

Other options do not encompass the same range of protective and restorative benefits as the combination of calcium hydroxide and glass ionomer. Thus, selecting this combination for deep cavities is based on their proven effectiveness in clinical practice.