What is the junction of three walls inside a cavity preparation identified as?

The junction of three walls inside a cavity preparation is referred to as a point angle. This term is specifically used to describe the intersection where two walls meet at an angle, and then a third wall intersects with those two, forming a point. In dentistry, understanding the different angles and junctions within a cavity preparation is crucial for effective restorative procedures, as it influences both the design of the cavity preparation and the subsequent placement of restorative materials.

In contextual terms, line angles refer to the junction of two walls rather than three, which is why they do not apply in this situation. The cavity floor pertains to the base of the preparation where it meets the pulpal space and is not the junction of walls. Lastly, the external surface describes the outside boundaries of the tooth or cavity and does not relate to the internal junctions formed by the walls of the cavity preparation. Therefore, the identification of the junction of three walls as a point angle is accurate and essential knowledge for dental practitioners working with cavity preparations.