Dental The W.H.O. periodontal probe (CPITN probe) has a black color coded rings A 0 to 0.5 mm B 3 to 3.5 mm C 8.5 to 11.5 mm D 3 to 5 mm 💡 Explanation The W.H.O. periodontal probe (CPITN probe) has a black color coded rings ✓ Correct Answer: C. 8.5 to 11.5 mm