Bond strength and internal adaptation of customized glass fiber posts using different bulk-fill flow resins

Abstract

Background This study aimed to evaluate the bond strength and internal adaptation of customized glass fiber posts using Bulk Fill flowable composite resins (BF) and conventional composite resin. Material and Methods Fifty bovine teeth were randomly divided (n=10) according to the following groups: G1 (control): glass fiber posts were adapted to the root canal and luted with Rely-X ARC cement (3M® ESPE); G2: fiber posts smaller than the root canal diameter were customized using Filtek™ Z350 XT (3M® ESPE) conventional composite resin, and luted similarly to Group 1. G3: posts were customized with Tetric N-Ceram Bulk Fill composite resin (Ivoclar Vivadent AG), G4: posts were customized with Filtek™ Bulk Fill Flow (3M® ESPE), and G5: posts were customized with SureFil SDRTM flow (DENTSPLY), respectively. The specimens were submitted to push-out testing and internal adaptation evaluation using optical microscopy. Push-out (MPa) and internal adaptation (%) data were subjected to ANOVA and Tukey’s post-hoc tests ( p = 5%). Results No statistically significant differences were found in both evaluations ( p <0.05). Conclusions Customized glass fiber posts using different bulk fill flowable composites did not affect the post bond-strength and internal adaptation, presenting similar results to customized glass fiber posts using conventional composite or posts with no previous customization. Key words: Dental pulp, composite resins, fiber posts, glass fiber post.

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

“…19,35,36 Relevant literature lacks information and general agreement about the ideal thickness of the cement layer between the fiber post and canal dentinal walls. 6,14,24,37 The cement layer is commonly the area where defects can occur in the form of voids or bubbles, and the junction between the resin cement and dentinal walls is the weakest and prone to failure such as debonding, particularly when there is an excessively thick cement layer in oversized flared root canals that are also associated with increased polymerization shrinkage stress. 14 Multiple studies have been conducted to evaluate the ideal luting cement thickness.…”

“…Several techniques have been reported in the literature to assess internal adaptation and fitting of fiber posts and other intraradicular dowels used to restore ETT: 1) slicing different regions of the root, followed by evaluation under the optical microscope 6 2) scanning electron microscopy 25 3) micro-computed tomography 24 or 4) utilizing PVS light-bodied impression material inserted into the root canal space. 21…”

“…[2][3][4][5] One of the crucial aspects is the intracanal adaptation of the fiberreinforced composite (FRC) post to the radicular dentin walls, which influences the retention of the intra-radicular restoration such as fiber posts. 6 Excessive removal of the radicular and coronal dentinal tissue occasionally occurs during endodontic procedures, such as over-flaring canals or attaining straight-line access. Additionally, several clinical situations are present with flared and wide root canal space, such as endodontic retreatment cases and immature permanent teeth with open apex, thus, requiring intraradicular posts for core retention.…”

“…2 3 4 5 One of the crucial aspects is the intracanal adaptation of the fiber-reinforced composite (FRC) post to the radicular dentin walls, which influences the retention of the intra-radicular restoration such as fiber posts. 6…”

“…11,12 Recent studies have proposed an alternative clinical technique to restore structurally-compromised ETT resulting from caries, trauma or congenitally malformed teeth, known as the anatomically customized or relined FRC posts. 6,8,[13][14][15] This technique involves relining the prefabricated FRC post using several conventional 8 and bulk-fill resin composites 6 to enhance adaptation on the walls of noncircular root canals. The adaptation was improved by fabricating anatomically-customized fiber posts that conform to the anatomy and taper of the root canal, thus limiting the thickness of the resin cement 16,17 Recently introduced bulkfill flowable, discontinuous short fiber-reinforced composite (SFRC) offers advantages and unique properties in restoring large ETT cavities.…”