Ohio Expanded Function Dental Assistant (EFDA) Board Practice Exam

In the context of dental restorations, particularly with amalgam, pulp protection is crucial in preserving the vitality of the pulp under conditions where the cavity preparation is shallow. When preparing a tooth for an amalgam restoration with minimal depth, the appropriate sequence of materials is essential to ensure effective sealing and protection for the underlying pulp.

Copal varnish is the material indicated for this scenario because it serves as a barrier between the restorative material (amalgam) and the tooth structure. It has the ability to seal dentinal tubules, minimizing post-operative sensitivity and protecting against micro-leakage. By applying copal varnish first, it prepares a smooth surface for the amalgam to adhere to, while also providing a protective seal that can help reduce the risk of irritation to the pulp.

Calcium hydroxide and zinc oxide eugenol are materials typically used for direct pulp capping or in deeper restorations where there is a concern regarding direct exposure to the pulp. Both have their specific indications; for instance, calcium hydroxide promotes some pulp healing due to its stimulating properties, and zinc oxide eugenol provides thermal insulation and soothing relief to irritated dental tissue. However, in minimal depth preparations where the risk of pulp exposure is lower, these are not