A finite element study of teeth restored with post and core: Effect of design, material, and ferrule

Abstract

Background:Different postdesigns and materials are available; however, no consensus exists regarding superiority for stress distribution. The aim of this study was to evaluate the effect of design and material of post with or without ferrule on stress distribution using finite element analysis.Materials and Methods:A total of 12 three-dimensional (3D) axisymmetric models of postretained central incisors were made: Six with ferrule design and six without it. Three of these six models had tapered posts, and three had parallel posts. The materials tested were titanium post with a composite resin core, nickel chromium cast post and core, and fiber reinforced composite (FRC) post with a composite resin core. The stress analysis was done using ANSYS software. The load of 100 N at an angle of 45΀ was applied 2 mm cervical to incisal edge on the palatal surface and results were analyzed using 3D von Mises criteria.Results:The highest amount of stress was in the cervical region. Overall, the stress in the tapered postsystem was more than the parallel one. FRC post and composite resin core recorded minimal stresses within the post but the stresses transmitted to cervical dentin were more as compared to other systems. Minimal stresses in cervical dentine were observed where the remaining coronal dentin was strengthen by ferrule.Conclusion:A rigid material with high modulus of elasticity for post and core system creates most uniform stress distribution pattern. Ferrule provides uniform distribution of stresses and decreases the cervical stresses.

A Case Report on Restoration of Traumatically Involved Teeth with Fiber Post and Esthetic Restoration

“…Similar study also revealed that less amount of dentinal stress in fiberreinforced composite core as compared to other system [13]. However, role of incorporation of ferrule could not be overlooked to minimize the stress [13,14].…”

“…First, the endodontic treatment was carried out in all of her traumatized teeth [11][12][13][14] then the radiographs were taken ( Figures 3 and 4). The tooth with greatest loss of coronal tooth structure [12] was judged to be a candidate for post-and-core restoration.…”

Influence of elastic modulus of intraradicular posts on the fracture load of roots restored with full crowns

“…with possibility of re-intervention and preservation of the tooth 4 . These findings may also be associated with the presence of a ferrule, which has a protective effect since it improves the mechanical behavior of pulpless teeth by reducing cervical stress level on the restored root 14,16 . Other studies have shown that the ferrule effect provided by remaining dentin is associated with restorable failure modes [20][21][22] .…”

“…The presence of a cervical ferrule positively affects the stress distribution pattern by reducing stress concentration on the root and risk of tooth fracture. Finite element analysis shows that the ferrule effect attenuates stress intensity on the root when either metal or fiber posts are used [12][13][14][15] . Previous studies also did not find a difference in fracture resistance between teeth restored with crowns and cast and post cores or fiber posts when a ferrule was present 13,16,17 .…”

Esthetic Restoration of Two Severely Decayed Maxillary Central Incisors: A Case Report

“…Fiber reinforced composite post (FRC) and composite resin core recorded minimal stresses within the post but the stresses transmitted to cervical dentin were more as compared to other systems. Minimal stresses in cervical dentine were observed where the remaining coronal dentin was strengthened by ferrule [13]. The position of the tooth in the arch, ferrule size, proximal contact, periodontal support and restoration type are survival prediction factors that should be considered when performing post-endodontic restoration [14].…”