Cementum covers resected root end in:
Proliferation of granulation tissue from the severed PDL was observed at 4 days, and the tissue had completely encapsulated the root end at 8 days. In the experimental groups, cementum deposition was observed at 12 days, and by 16 days, cementum covered more than 50% of the surface areas of the resected root ends. 
The complete healing will take around 4 weeks.
12 days
20 days
28 days
8 weeks