Effect of different ferrule designs on the fracture resistance and failure pattern of endodontically treated teeth restored with fiber posts and all-ceramic crowns

Abstract

ObjectiveThis study investigated the effect of different ferrule heights on endodontically treated premolars.Materials and MethodsFifty sound mandibular first premolars were endodontically treated and then restored with 7-mm fiber post (FRC Postec Plus #1 Ivoclar-Vivadent) luted with self-polymerized resin cement (Multilink, Ivoclar Vivadent) while the coronal section was restored with hybrid composite core build-up material (Tetric Ceram, Ivoclar-Vivadent), which received all-ceramic crown. Different ferrule heights were investigated: 1-mm circumferential ferrule without post and core (group 1 used as control), a circumferential 1-mm ferrule (group 2), non-uniform ferrule 2-mm buccally and 1-mm lingually (group 3), non-uniform ferrule 3-mm buccally and 2-mm lingually (group 4), and finally no ferrule preparation (group 5). The fracture load and failure pattern of the tested groups were investigated by applying axial load to the ceramic crowns (n=10). Data were analyzed statistically by one-way ANOVA and Tukey’s post-hoc test was used for pair-wise comparisons (α=0.05).ResultsThere were no significant differences among the failure load of all tested groups (P<0.780). The control group had the lowest fracture resistance (891.43±202.22 N) and the highest catastrophic failure rate (P<0.05). Compared to the control group, the use of fiber post reduced the percentage of catastrophic failure while increasing the ferrule height did not influence the fracture resistance of the restored specimens.ConclusionsWithin the limitations of this study, increasing the ferrule length did not influence the fracture resistance of endodontically treated teeth restored with glass ceramic crowns. Insertion of a fiber post could reduce the percentage of catastrophic failure of these restorations under function.

Mechanical behavior of endodontically restored canine teeth: Effects of ferrule, post material and shape

“…As a consequence of the ferrule effect, post/core ratios are increased, fluid erosion of the luting cement is reduced and post retention is improved. Some controversies exist about the optimum height of remaining tooth structure and the location of supragingival structures [29][30][31][32][33].…”

The effect of ferrule on the fracture mode of endodontically treated canines restored with fibre posts and metal-ceramic or all-ceramic crowns

“…27,28 This was confirmed by a retrospective clinical study that showed that the presence of a post had little effect on the fracture rate of a crowned tooth. 29 Sherfudhin et al 30 reported that the use of fibre posts changed the catastrophic failure type of the control group (no post) to almost complete favourable fracture for the other groups that consisted of various ferrule designs and allceramic crowns.…”

The Effect of Glass Fiber‐Reinforced Epoxy Resin Dowel Diameter on the Fracture Resistance of Endodontically Treated Teeth

“…Thus, the study design resembled the in vivo condition, allowing extrapolation of results to the clinical situation . However, some studies have shown that different ferrule designs did not have any significant influence on the fracture resistance of teeth restored with fiber dowels . This contrasted with other studies that showed that increased ferrule length improved the mechanical behavior of teeth restored with metal crowns irrespective of dowel or core type .…”

“…Hu et al concluded that using an FRC dowel might lead to a long fatigue life in restoring pulpless teeth with flared canals, and that dentin ferrule preparation was necessary to enhance the restorations’ resistance to cyclic fatigue . Besides, the insertion of a fiber dowel could reduce the percentage of catastrophic failure of these restorations under function . Schmitter et al found that increased ferrule height and resin bonding of the crown resulted in higher fracture loads.…”