Present status and future directions: vertical root fractures in root filled teeth

Abstract

Vertical root fracture (VRF) is a common reason for the extraction of root filled teeth. The accurate diagnosis of VRF may be challenging due to the absence of clinical signs, whilst conventional radiographic assessment is often inconclusive. However, an understanding of the aetiology of VRFs, and more importantly, the key predisposing factors, is crucial in identifying teeth that may be susceptible. Thorough clinical examination with magnification and co‐axial lighting is essential in identifying VRFs, and although CBCT is unable to reliably detect VRFs per se, the pattern of bone loss typically associated with VRF can be fully appreciated, and therefore, increases the probability of correct diagnosis and management. The prevalence of VRFs in root filled teeth is significantly greater than in teeth with vital pulps, demonstrating that the combination of loss of structural integrity, presence of pre‐existing fractures and biochemical effects of loss of vitality is highly relevant. Careful assessment of the occlusal scheme, presence of deflective contacts and identification of parafunctional habits are imperative in both preventing and managing VRFs. Furthermore, anatomical factors such as root canal morphology may predispose certain teeth to VRF. The influence of access cavity design and root canal instrumentation protocols should be considered although the impact of these on the fracture resistance of root filled teeth is not clearly validated. The post‐endodontic restoration of root filled teeth should be expedient and considerate to the residual tooth structure. Posts should be placed ‘passively’ and excessive ‘post‐space’ preparation should be avoided. This narrative review aims to present the aetiology, potential predisposing factors, histopathology, diagnosis and management of VRF and present perspectives for future research. Currently, there are limited options other than extraction for the management of VRF, although root resection may be considered in multi‐rooted teeth. Innovative techniques to ‘repair’ VRFs using both orthograde and surgical approaches require further research and validation. The prevention of VRFs is critical; identifying susceptible teeth, utilizing conservative endodontic procedures, together with expedient and appropriate post‐endodontic restorative procedures is paramount to reducing the incidence of terminal VRFs.

Evolution of the combined effect of different irrigation solutions and activation techniques on the removal of smear layer and dentin microhardness in oval-shaped root canal – An in-vitro study

“…Among these, changes in biomechanical properties of dentine were considered a predisposing risk factor. The use of intracanal disinfectants and medicaments may reduce the microhardness, elastic modulus and fracture resistance of the dentin; moreover, prolonged exposure to these agents may further increase susceptibility to VRF [18]. According to Uzunoglu et al, the mean fracture resistance of teeth treated with 17% EDTA for 10 minutes was about 2 times less than teeth treated with 5% EDTA for 10 minutes [19].…”

Wear Analysis of Four Different Single-File Reciprocating Instruments before and after Four Uses in Simulated Root Canals

“…The OR is a recently introduced single-file reciprocating instrument characterized by two different cross-section designs; a convex triangular for the apical 4 mm and an S-shaped for the rest of the instrument with a patented asymmetric cross-section. This manufacturing choice is probably intended to enhance the mechanical properties of the instrument, increasing the torsional resistance of the tip by increasing its polar moment of inertia [16] and increasing the cyclic fatigue resistance and the flexibility of the coronal part by reducing the cross-sectional mass with the S-shaped design [17]. Moreover, while the tip diameter is 0.25 mm, the taper is 0.06 variable and it is drastically reduced in the coronal part of the instrument thanks to the use of 1 mm wire diameter for its manufacturing, to preserve peri-cervical dentin during the instrumentation procedures [18].…”

Estrategias para la utilización de la tomografía de haz cónico en dientes con sospecha de fractura radicular. Reporte de serie casos

“…Las fracturas radiculares constituyen después de la caries y la enfermedad periodontal la tercera causa de pérdida de unidades dentarias ( 3 ), son más comunes en dientes endodónticamente tratados (3,69-25%) ( 3,4 ) y más frecuentes en dientes posteriores, entre ellos los premolares superiores y molares inferiores ( 5,6 ). Se considera que su frecuencia aumenta con la edad, y es mayor entre los 30 y 69 años, sin predilección por sexo ( 3 ).…”