The effect of ferrule presence and type of dowel on fracture resistance of endodontically treated teeth restored with metal-ceramic crowns

Abstract

Aim:The purpose of the present study was to comparatively evaluate the effect of presence of a 2 mm ferrule and different type of dowels on fracture resistance of mandibular premolars.Materials and Methods:Fifty uniradicular mandibular premolars were divided into five groups (n = 10). Ten teeth received no treatment (group I). Samples in group II & III were decoronated 2 mm above cemento-enamel junction and received custom cast dowel-core and fiber dowel-composite core respectively, with 2 mm ferrule. Samples in group IV & V were decoronated at CEJ and were restored using cast dowels and fiber dowel-composite cores, without any ferrule. The restored teeth received metal ceramic crowns and were mechanically loaded. The specimens were subjected to a static load, until fracture, to determine the fracture resistance and fracture mode.Results:The samples with 2 mm ferrule had a higher fracture resistance than non ferrule groups. Within non ferrule groups, there were no significant differences in the fracture resistance. Specimen restored with cast dowel had more incidence of non-repairable fracture.Conclusions:Presence of ferrule increased the fracture resistance of endodontically treated teeth. In case of absence of ferrule, fiber dowels had similar fracture resistance as that of cast dowels and showed increased incidence of repairable fracture.

Influence of cement type and thickness on polyfiber post adhesion

“…Fiber reinforced posts (18-22 GPa) have a modulus of elasticity similar to the dentine (18 GPa);[ 2 ] they produce a stress field similar to that of natural teeth, thereby reducing the risk of root fractures[ 3 4 ] In addition, fiber posts showed increased incidence of repairable fracture when compared to cast dowel posts. [ 5 ]…”

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

“…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] .…”

A Simplified Technique for Repair an Abutment Tooth under Preexisting Crown: A Case Report

“…The cast dowel with 2 mm ferrule had a high fracture resistance but led to non-repairable fracture. Without ferrule, fiber post had a high incidence of repairable fracture [3]. Various authors have suggested different methods to replace or fabricate a post and core using retrograde postsupported core build up with the pre-existing crown or fixed partial denture [4][5][6][7].…”