Fig.2 (intraop photo) shows thread exposure. The defect is a preexisting condition. Bone graft may be not enough or get infected. Or the implant is oversized, or placed too buccally (because of palatal defect). In all, the implant is ~ 1 mm from the cortex.
Xin Wei, DDS, PhD, MS 1st edition 12/29/2014, last revision 02/14/2015