Periapical implant pathology.

Periapical implant pathology, a distinct dental lesion, is the coalescence of adjacent periapical pathology with the apical segment of a dental implant that results in a common lesion. I present four cases to document two proposed case types: type 1, implant to tooth, which occurs during osteotomy preparation either by direct trauma or through indirect damage and causes adjacent pulp to undergo devitalization; and type 2, tooth to implant, which occurs shortly after placement of the implant when an adjacent tooth develops periapical pathology, either by operative damage to the pulp or through reactivation of a prior apical lesion. In both types, the resulting periapical pathology contaminates the fixture and inhibits osseointegration of the implant during stage 1 healing. These two case types are presented to help clarify the use of etiology as the basis of a classification system.