Vertical Root Fracture (VRF)

Definition
Vertical Root Fracture (VRF) is a type of longitudinal fracture that originates from the root and predominantly extends in the faciolingual (labio-lingual) direction.

Nature and Pathology

VRF may be complete or incomplete and can initiate from any surface of the root.
The fracture typically extends to the periodontal ligament (PDL).

Secondary Effects

Due to bacterial penetration into the fracture line and root canal space, VRF causes significant damage to the surrounding periodontal soft and hard tissues.

Differential Diagnosis

VRF often mimics other conditions such as periodontal disease or failed root canal therapy.

Etiology of VRF

Root canal–treated teeth: VRF most commonly occurs in teeth that have undergone endodontic treatment, frequently restored with posts.
Post placement: Post insertion is considered one of the primary etiological factors.
Excessive condensation forces: Overuse of condensation forces during obturation of underprepared or overprepared canals is another secondary cause.
Root anatomy: The presence of two canals within a single root, an isthmus (narrow connection between canals), and condensation forces during obturation increase susceptibility.
Structural weakening: Excessive removal of dentin or natural occlusal stresses may also predispose teeth to VRF.

Clinical Signs and Considerations

Patients often present with minimal symptoms.
A combination of clinical and radiographic findings may suggest VRF:
- Clinical history: Dental history, pain, swelling, sinus tract formation, and/or isolated deep periodontal pockets.
- Periodontal examination: Although probing patterns may appear normal, deep, narrow, or rectangular defects are frequently observed. Chronic VRF is often associated with a deep, narrow periodontal pocket, with or without a sinus tract.
- Bleeding observation: Fresh bleeding during post space preparation may indicate perforation or root fracture.
- Diagnostic uncertainty: Clinical signs, probing patterns, and radiographic findings are not definitive for VRF.

Radiographic Findings and Diagnosis

Conventional radiography (2D): Radiographic evidence is variable; separation of root fragments is rarely visible. Lesions often appear as J-shaped or halo-shaped radiolucencies extending from the apical region to lateral surfaces.
Cone-Beam Computed Tomography (CBCT):
- CBCT is the preferred imaging modality for VRF diagnosis.
- It reveals the presence and morphology of bone lesions but is less reliable for direct visualization of fracture lines.
- Sensitivity of CBCT in detecting VRF is higher than 2D radiography (79.4% vs. 37.1% in one study).
- Artifacts and limitations: Diagnostic accuracy depends on fracture size and spatial resolution. Root filling materials and metallic posts may produce radiographic artifacts (streaking) that either simulate fractures (false positives) or obscure existing ones (false negatives).

Five CBCT findings consistent with confirmed VRF include:

Mid-root bone loss with intact coronal and apical bone.
Complete absence of the buccal cortical plate.
Radiolucency surrounding the root where a post terminates.
Separation between buccal/lingual cortical plate and fractured root surface.
Visualization of vertical fracture lines in multiplanar CBCT sections.

Definitive diagnosis (gold standard): Flap reflection and direct visualization of the fracture, often accompanied by a punched-out bony defect. The use of dye during surgery is also considered the gold standard for VRF diagnosis.

Management and Considerations

Prevention:

Proper canal preparation and balanced condensation pressure during obturation are essential.
Excessive condensation should be avoided.
Finger spreaders, particularly nickel-titanium spreaders, generate less stress compared to hand instruments.
Preservation of pericervical dentin enhances resistance against occlusal forces and fracture.

Prognosis:

Complete VRF carries a hopeless prognosis.

Treatment:

Once VRF is identified, extraction of the affected tooth or removal of the fractured root is required.
In multi-rooted teeth, treatment may involve root resection or extraction of the entire tooth.
When previous endodontic failure is attributed to VRF, prognosis is poor, and extraction or root removal should be considered.

Key Points (Summary)

VRF is a longitudinal fracture originating from the root, commonly occurring after root canal therapy due to condensation forces or post placement.
Complete VRF results in an untreatable condition.
VRF is frequently associated with deep, narrow periodontal pockets and J-shaped radiographic lesions.
Although CBCT is the imaging modality of choice, definitive diagnosis often requires surgical visualization with flap reflection and/or dye application.
Prevention through proper canal preparation and minimal condensation pressure is the best strategy.
Treatment of complete VRF involves extraction or removal of the affected root.

References
Torabinejad, M., Fouad, A. F., Shabahang, S. (2020). Endodontics E-Book. Netherlands: Elsevier.