Which aspect of a cavity prep includes the axial and gingival walls?

Which aspect of a cavity prep includes the axial and gingival walls?

• A. Class I
• B. Class II
• C. Class III
• D. Class IV

Answer: (B)

When a cavity prep has an interior box that reaches the proximal surface, the two defining walls are the axial wall and the gingival wall. The axial wall runs toward the tooth’s pulp and forms the inner boundary of that proximal box, while the gingival wall (gingival floor) is the bottom boundary near the gumline. This proximal box configuration is a hallmark of a Class II preparation on posterior teeth, created to access and restore a lesion on a proximal surface while preserving as much tooth structure as possible. The other classes don’t routinely feature this proximal box with both an axial wall and a gingival floor in their standard descriptions, so the combination of these two walls points to a Class II preparation.

When a cavity prep has an interior box that reaches the proximal surface, the two defining walls are the axial wall and the gingival wall. The axial wall runs toward the tooth’s pulp and forms the inner boundary of that proximal box, while the gingival wall (gingival floor) is the bottom boundary near the gumline. This proximal box configuration is a hallmark of a Class II preparation on posterior teeth, created to access and restore a lesion on a proximal surface while preserving as much tooth structure as possible. The other classes don’t routinely feature this proximal box with both an axial wall and a gingival floor in their standard descriptions, so the combination of these two walls points to a Class II preparation.