The implant periapical lesion: etiology, prevention, and treatment.

A classification of implant periapical lesions that separates them into inactive and infected has been suggested. The inactive form is likely to be an apical scar, resulting from a residual bone cavity created by placing an implant that was shorter than the prepared drill site. The infected focus probably occurs when an implant apex is placed in proximity to an existing infection or when a contaminated implant is placed. Bone necrosis caused by overheating during preparation may also be a causative factor. Suggested preventions of implant periapical lesions include careful management of contaminants and heat generation during implant surgery. Treatment varies according to the type of lesion. The inactive type is observed and monitored. The infected type requires surgical intervention, elimination of the infection, and an implant apical resection or implant removal depending on the extent of the infection and the stability of the implant.