To plan the line-angles in the proximal cavity in a class II you use:
- A- Straight chisel.
- B- Biangled chisel.
- C- Enamel hatchet.
The correct answer for planning line-angles in the proximal cavity of a class II cavity is: C. Enamel hatchet.
Here's why:
- Straight chisels:
These are primarily used for removing large amounts of tooth structure and creating box outlines in occlusal cavities. They wouldn't be ideal for defining precise line angles in proximal boxes requiring smooth, bevelled margins.
- Biangled chisels:
While these can be used for some proximal cavity extensions, their primary function is in buccal and lingual extensions, not line angle definition.
- Enamel hatchet:
This instrument is specifically designed for defining smooth, bevelled enamel margins. Its narrow blade and angulation make it ideal for creating precise line angles, particularly in the axiogingival and linguocervical areas of the proximal box.
Therefore, the enamel hatchet provides the best control and precision for planning and creating the desired line angles in a class II proximal cavity.
