This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
I- brush is used In case of 
Select and explain. 
A. Gingival recession, B. Peri-implantitis, C. Post periodontal surgery, D. For regular cleaning of teeth
B: Peri-implantitis
Answer: B: Peri-implantitis 
Explanation: None