The Histopathogenesis of Vertical Root Fractures

By Walton R, Michelich R, Smith N

Date: 01/1984
Journal: JOE

Purpose:

To histologically examine roots and periodontium of vertical root fracture diagnosis in attempt to elucidate the cause of such drastic tissue response adjacent to fractures

Materials/Methods:

N= 36 roots diagnosed with vertical root fracture and deemed hopeless

Teeth fixed in formalin, decalcified, and embedded in paraffin. Majority of the roots cut in cross-section, some vertically to evaluate the fracture along the root length. Adjacent sections exposed to the following stains: (1) H&E stain to eval soft & hard tissue morphology changes, (2) Bacterial stain to identify bacteria, (3) Wilder’s reticulum to characterize granulation (reparative) tissue. Microscopic examination

Evaluation criteria: extent and location of fracture lines, location/concentration/nature of bacteria present in canals, nature/contents of canal adjacent to fracture, evidence/identification of foreign debris, presence & location of obturation material in fracture and adjacent periodontal tissues

Results:

Fracture characterisitics: 90% complete fracture (extends to opposite root surface), 10% incomplete (only extend to one root surface). In the longitudinally sectioned roots, most had a fracture from cervix to apex. F-L fracture if it started apically. M-D fracture in molars & premolars if start coronally. All fractures opened into canals. Secondary cracks not extending to root surface were frequently observed

Bacterial characteristics: gram + predominated (32/36 canals), gram – also found. Bacteria found in defects, secondary fractures, dentinal tubules that communicated with fracture. Most often found in low concentrations, occasional dense plaque-resembling accumulations

Canal contents: necrotic tissue, bacteria, food and other debris; sometimes seen extending into secondary fracture spaces

Fracture contents: foreign material, gp, sealer

Tissue reaction: inflamed soft tissue (chronic, granulomatous), some resorption, cementum-like tissue within fracture line in some specimens.

Clinical Significance:

The fracture opens a wide pathway for irritants to access the highly reactive periodontium, though the precise etiology was not identified in this study.