Resistance to root fracture of dowel channels with various thicknesses of buccal dentin walls

Fracture resistance of teeth with oval canal morphology restored using oval and circular posts

“…Using oval fiber posts in oval canals is therefore appropriate as poor adaptation of a post to the canal wall may result in shrinkage, and the greater resin cement thickness may be detrimental to the long-term clinical performance (17). Although increasing the diameter of a circular post may fix this problem, restorations with larger circular fiber posts have poor fracture resistance because of decreased remaining root dentin (27), leading to increased incidence of vertical root fractures (28). In a previous study, Coniglio et al (11) investigated the cement thickness upon use of oval and circular posts in premolar root canals.…”

A comparison of the survival of fibre posts cemented with two different composite resin systems

“…7 The most common modes of failure associated with metal posts include loss of retention, root fracture or post fracture. [8][9][10][11][12] The above diffi culties associated with metal posts coupled with developments…”

Tooth preparation for post-retained restorations

“…Some authors have questioned the benefit of the ferrule, 66 however the majority of the literature would support its importance in reducing root fracture due to functional lever and torsional forces, and the wedging effect of tapered posts. [70][71][72][73][74][75][76][77][78] Barkhordar et al in 1989 72 compared restored teeth that were prepared with and without a ferrule and showed that the ferrule reduced vertical root fracture by one-third.…”

“…65 The more dentine remaining buccal to the post, the less prone the root is to fracture under horizontal impact. 66 However, teeth obviously vary in diameter and a post diameter less than 1 mm would be recommended for lower incisor teeth, for example. It is important that when viewing preoperative radiographs root morphology is borne in mind, as a lower incisor may appear a certain width radiographically, but this tooth has a root with a mesial and distal concavity in cross-section.…”