Adaptation of Relined Fiber Post Using Discontinuous Short Fiber-Reinforced Resin Composite to Restore Weakened Endodontically-Treated Premolars

Abstract

Objective This study aimed to investigate the effect of relining prefabricated fiber-reinforced composite (FRC) posts using bulk-fill, flowable, discontinuous short fiber-reinforced composite (SFRC) on intracanal adaptation in weakened endodontically-treated premolar teeth. Materials and Methods Forty extracted human premolar teeth were selected and randomly allocated to five groups (n = 8) according to the canal preparation method and restorative technique after endodontic treatment: Group 1 (control): nonflared, closed apex root canals; group 2, 4: flared, open-apex root canals; group 3, 5: flared, closed apex root canals. Groups 1 to 3 were restored with standard RelyX fiber post size #1, while groups 4 and 5 were restored with customized RelyX fiber post size #1 and relined with bulk-fill flowable SFRC (everX Flow, GC, Tokyo, Japan). To evaluate intracanal adaptation, the empty root of each sample with the corresponding fiber post (standard or customized) inserted was measured twice using a micro-digital scale and the average value was calculated. The post was then removed, followed by the insertion of a light body polyvinyl siloxane (PVS) impression material into the canal, followed by reinsertion of the post and removal of excess material once the PVS was set. Finally, the sample weight was recorded, and the data were analyzed using one-way analysis of variance and the Bonferroni post hoc test (p-value = 0.05). Results A statistically significant difference (p < 0.05) in PVS material weight was identified between the groups. Group 1 (control) had the lightest weight of PVS material, followed by groups restored with customized fiber posts (groups 4 and 5) and standard fiber posts (groups 2 and 3). Conclusion Anatomically-customized fiber posts with bulk-fill flowable SFRC provided better intracanal adaptation compared with standard fiber posts in teeth with compromised root canals.

Evaluation of mechanical properties of anatomically customized fiber posts using E-glass short fiber-reinforced composite to restore weakened endodontically treated premolars

“…The higher incidence of complete debonding of post and core complex in Group 2 and 3 can be explained by the mismatch in dimensions and geometry of the fiber posts and the simulated flared root canals, which was more evident in Group 2 with simulated open apex as the walls were prepared parallel without any taper. In a previous study carried out by the same research group, anatomically customized FRC posts in flared canals with closed or open apex presented significantly higher adaptation and fitment to radicular walls than in samples with flared canals and closed or open apex restored with standard FRC posts [ 9 ]. The inferior adaptation in Group 2 and Group 3 might have led to the presence of an excessively thick cement layer occupying majority of the root canal space in the coronal, middle and apical region.…”

“…Improved intracanal adaptation was confirmed with the anatomically customized FRC posts [ 9 ]. This means that the excessive space around the post in a flared root canal is being occupied by the relining resin composite material with sufficient curing, mechanical and physical properties instead of the weak resin cement layer.…”

“…This technique involves relining the prefabricated FRC post using either conventional [ 4 ] or bulk-fill resin composites [ 6 ] to enhance adaptation on the walls of non-circular root canals. The adapation was improved by fabricating anatomically-customised fibre posts that conform to the anatomy and taper of the root canal, thus limiting the thickness of the resin cement [ 7 – 9 ].…”

Comparative Evaluation of Fracture Resistance of Carbon Fiber Posts and Glass Fiber Posts in Permanent Anterior Teeth: An In Vitro Study

“…Utilizing in vitro testing methodologies serves as a means to evaluate effectiveness; however, these tests are inherently limited as they do not fully replicate the dynamic intraoral environment [16]. Furthermore, they lack comprehensive insights into the behavior of the tooth restoration complex prior to failure.…”

Evaluation of microhardness of short fiber-reinforced composites inside the root canal after different light curing methods – An in vitro study

“…FRC post relining seeks to address the challenges associated with conventional FRC posts, including misfitting, bonding between the FRC post and the relining composite material, and the distribution of fibers in the critical cervical region. With the emergence of flowable short fiber-reinforced composite (SFRC) in the market, it is now possible to incorporate short fibers into this method [27,28]. It is therefore reasonable to assert that the future success of FRC post relining largely hinges on the choice of FRC post (conventional or elastic) and the type of material (fiber or non-fiber-reinforced) used for relining.…”