Dental While sharpening curettes and sickles, the internal angle of _________ must be preserved between the face and lateral it surface A 50-60 B 60-70 C 70-80 D 80-90 💡 Explanation While sharpening curettes and sickles, the internal angle of _________ must be preserved between the face and lateral it surface ✓ Correct Answer: C. 70-80