The pulpal floor is best described as which part of a dental prep?

• A. The deepest portion of the prep
• B. The enamel margin
• C. The occlusal surface
• D. The cementum edge

Answer: (A)

In cavity preparation, the deepest part of the prepared cavity, the surface that faces the pulp chamber, is the pulpal floor. It forms the bottom of the preparation and is typically made of dentin. This surface sets how far you must cut into the tooth to reach the proper depth for the restoration while protecting the pulp. The enamel margin is the edge around the top of the prep where enamel remains, the occlusal surface is the tooth’s chewing surface outside the prep, and the cementum edge would be at the root side. So the pulpal floor is simply the bottom, deepest surface oriented toward the pulp.