A = partial implant drill intrusion into mandibular canal can cause direct mechanical IAN trauma - encroach, or laceration and primary ischemia.
B = full implant drill intrusion into mandibular canal can cause direct IAN transection and primary ischemia.
C = partial implant drill intrusion into mandibular canal can cause indirect trauma due to hematoma and secondary ischemia.
D = thermal stimuli can evoke periimplant bone necrosis and postoperative secondary IAN damage.
E = thermal stimuli can evoke primary IAN damage.