Dental While preparing the proximal box, the mesiodistal width of the ditch should be: A 0.8 mm ; two thirds in dentin and one third at the expense of enamel B 0.8 mm ; one third in dentin and two thirds at the expense of enamel C 0.8 mm ; full depth in dentin D 0.8 mm ; full depth in enamel 💡 Explanation While preparing the proximal box, the mesiodistal width of the ditch should be: ✓ Correct Answer: A. 0.8 mm ; two thirds in dentin and one third at the expense of enamel