The histopathogenesis of vertical root fractures.

Fractured roots were examined histologically, using different stains, to study the morphological fracture patterns and to identify potential irritants. Fractures were usually, but not always, complete and extended from a surface to include the root canal. The potential irritants identified in both the fracture space and communicating canal were bacteria, necrotic tissue, food debris, and unidentifiable amorphous substances. Soft tissues on the root surface adjacent to the fracture were inflamed with occasional ingrowth into the fracture space. The nature of the fractures and irritants demonstrated why vertical root fractures often cause marked tissue destruction.