The reason to use post is to retain the core that holds the definitive prosthesis. The maxillary central incisor always poses a challenge during reconstruction using the post and core system. Dentapreg PINPost, a pre-cured flexible post made of fiber-reinforced composite (FRC), has many advantages over metallic posts and fiber posts. The purpose of this case report is to present an innovative technique to place both FRC posts and FRC sheets as a single assembly into the canal which gives a monoblock effect. This technique is feasible and may eradicate some of the problems associated with the failure of the post and core.

OBJECTIVE: This study was conducted to assess the influence of combining different forms of fiber-reinforced composites (FRC) on the mechanical behavior and bond strength of compromised endodontically treated teeth (ETT).
METHODS: Eighty extracted human premolar teeth were randomly divided into five experimental groups according to the type of intra-radicular restoration and the canal preparation design which was either non-flared (Group 1), flared (Groups 2-5), closed-apex (Groups 1,3,5) or open-apex (Groups 2,4). Standard prefabricated fiber posts were used as intra-radicular restoration for Groups 1-3 while Groups 4-5 were restored with anatomically customized relined fiber posts. After composite core fabrication, all samples were sent for an artificial aging process. Fracture resistance and push-out bond strength tests were then carried out through a universal testing machine followed by mode of failure analysis via a stereomicroscope and scanning electron microscope.
RESULTS: Pairwise Log-Rank comparisons revealed that the survival rate of Group 2 and Group 3 was significantly lower than all other groups after artificial aging. The highest fracture resistance value (1796 N) was recorded in Group 5 and was significantly higher than that of the other groups (p < 0.05), while Group 2 exhibited the lowest fracture resistance (758 N), which was significantly lower compared to the other groups. Group 5 and Group 4 demonstrated a significantly higher push-out bond strength, at all root thirds, than Group 3, Group 2, and Group 1 (p < 0.05). The most frequently observed failure mode in the tested groups occurred between the resin cement and radicular dentin.
CONCLUSIONS: The use of short fiber-reinforced composite (SFRC) to reline the prefabricated FRC post has been proven to have superior fracture resistance with favorable failure patterns and increased push-out bond strength values compared to standard prefabricated FRC posts.

This investigation evaluated the effects of aprotic solvents, i.e., tetrahydrofuran, pyridine, and morpholine, compared with hydrogen peroxide, on the surfaces of fiber-reinforced composite posts with a composite core based on the microtensile bond strength. In total, 150 FRC Postec Plus posts and 150 D.T. Light-Posts were randomly divided into three groups (non-thermocycling, 5000-cycle, and 10,000-cycle thermocycling groups). Each group was divided into five subgroups according to the post-surface treatment: C, non-treatment group; H2O2, immersed in 35% hydrogen peroxide; THF, immersed in tetrahydrofuran; PY, immersed in pyridine; and MP, immersed in morpholine. The treated specimens were placed in the bottom of a plastic cap and filled with a composite core material in preparation for the microtensile bond test. The data were evaluated using one-way ANOVA and Tukey\'s test (p < 0.05) as well as an independent t-test (p < 0.05). For the surface roughness, white light interferometry was used for measurement, and the mean surface roughness was analyzed via one-way ANOVA and Tukey\'s test (p < 0.05). The results showed that, under non-thermocycling conditions, the PY subgroup with D.T. Light-Post had the highest microtensile bond strength, followed by THF, MP, H2O2, and the control groups. For FRC Postec Plus, the PY group had the highest microtensile bond strength, followed by MP, THF, H2O2, and the control groups. Although the thermocycling conditions decreased the microtensile bond strength in all groups, the PY subgroup still had the highest value. An independent t-test revealed that even under all non-thermocycling and 5000- and 10,000-cycle thermocycling conditions, D.T. Light-Post in the PY subgroup displayed significantly higher microtensile bond strengths than FRC Postec Plus in the PY subgroup. While the surface roughness of the fiber-reinforced composite posts showed that the posts treated with pyridine possessed the highest surface roughness for each material type, In conclusion, as an aprotic solvent, pyridine generates the highest microtensile bond strength between the interfaces of composite cores and fiber-reinforced composite posts.

The aim of this study was to assess adaptation and bonding to root canal dentin of discontinuous (short) glass fiber-reinforced composite to intra-radicular dentin (DSGFRC).
METHODS: Seventy virgin human teeth were extracted and then endodontically treated; then samples were randomly divided into 7 groups (n = 10), based on the materials\' combinations as follows: Group 1, a two-bottle universal adhesive + DSGFRC; Group 2, a single-component universal adhesive + DSGFRC; Groups 3 and 4, the same materials of Goups 1 and 2 were used but after cleaning of the canal walls with 17% EDTA and final irrigation with 5.25% NaOCl Ultrasound Activated (UA); Group 5, traditional prefabricated fiber posts were luted after being silanized with G-Multi Primer; Groups 6 and 7, like Group 5 but after ultrasonic irrigation (UA). All sample roots were cut 1 mm thick (n = 10) to be evaluated regarding root canal adaptation using a light microscope and scanning electron microscope (SEM) and push-out bond strength. These results were statistically analyzed by Kruskal-Wallis analysis of variance by ranks. The level of significance was set at p < 0.05.
RESULTS: Bond strength forces varied between 6.66 and 8.37 MPa and no statistically significant differences were recorded among the groups. By microscopic examination, it was noted that ultrasonic irrigation increased the adaptation of the materials to the dentin surface.
CONCLUSIONS: Within the limitations of this in vitro study, it may be concluded that when DSGFRC was used for intracanal anchorage in the post-endodontic reconstruction, similar push-out retentive force and strength to those of traditional fiber posts cemented with particulate filler resin composite cements were achieved.

Background and Objectives: One requirement for the cemented post is the light transmittance on its entire length up to the deepest portion of a root canal to ensure the complete polymerization of resin cement. This study aimed to determine the light transmission ability in different aesthetic posts at different depths and its effect on the push-out bond strength and microhardness of luting cement at the corresponding interface. Materials and Methods: Twenty endodontic posts from glass fiber posts (GFP), zirconia ceramic posts (ZCP), and highly translucent zirconium oxide posts (HTZP) were sequentially sectioned into 12.8 and 4 mm lengths after recording the light intensity using a dental radiometer. Sixty single rooted premolar teeth root canals were treated and implanted vertically in a resin block. The post space was prepared and cemented with GFP, ZCP, and HTZP posts with twenty samples each. The root portion of teeth samples were sectioned into cervical, middle, and apical portion. A universal testing machine was utilized for the push-out bond strength test for the first ten samples from each group. The remaining ten samples from each group were used for the microhardness test using a micro-indenter instrument. The data were statistically analyzed using one-way Analysis of variance and Tukey HSD tests at p < 0.05. Results: The GFP endodontic postpresented with significant highest light translucency compared to HTZP, which was significantly higher than ZCP. GFP posts showed significantly higher bond strength per unit area compared to ZCP at analogous cross sections. The hardness of luting cement was also significantly higher amongst all tested endodontic posts. Conclusions: GFP high light translucency enhanced the curing of the luting resin cement that resulted in harder cement and a stronger bond supported by hardness and push-out tests. These findings suggest that GFP is preferred to be used with light-cured luting cements for restoration of endodontically treated teeth.

Although several techniques have been proposed to remove fiber-reinforced composite (FRC) post, no safe and efficient technique has been established. Recently, a guided endodontics technique has been introduced in cases of pulp canal obliteration. This study describes 2 cases of FRC post removal from maxillary anterior teeth using this guided endodontics technique with a dental operating microscope. Optically scanned data set from plaster cast model was superimposed with the data set of cone-beam computed tomography. By implant planning software, the path of a guide drill was selected. Based on them, a customized stent was fabricated and utilized to remove the FRC post. Employing guided endodontics, the FRC post was removed quickly and safely with minimizing the loss of the remaining tooth structure. The guided endodontics was a useful option for FRC post removal.

This clinical report describes the rehabilitation procedure of an upper central tooth with a coronal fracture without compromising the root. The treatment plan consisted of the reinsertion of the fractured fragment as a definitive cemented biological restoration. Due to the deficient remnant, a fiber-reinforced composite post was used. The objective of this clinical case was to report the biological behavior of the enamel and dentin of a biological restoration after dental trauma. Patient satisfaction with the treatment was achieved by continuing with the same tooth and biomimetizing the fracture line with conventional composites. Controls were conducted, and 1 year after dental trauma, no color changes in dental tissues and no inflammation in periodontal and soft tissues were observed.

BACKGROUND: The primary reason for using a post is to retain the core with the objective to restore the missing coronal tooth structure. To achieve optimum results, the materials that are used to restore endodontically treated teeth should have physical and mechanical properties that are similar to that of dentin.
OBJECTIVE: To characterize the strength parameters of fiber-reinforced composite (FRC) posts with the application of a three-point test. The mean fracture load, flexural strength and flexural modulus were taken into consideration.
METHODS: For the three-point strength tests, 5 kinds of fiberglass root-posts were used: GC Fiber Post (GC America, Alsip, USA), Mirafit White (Hager Werken, Duisburg, Germany), Innopost (InnoTech, Verona, Italy), Rebilda Post (Voco, Cuxhaven, Germany), and EverStick Post (GC Europe, Leuven, Belgium). For each system, 15 FRC posts were tested. All posts had the same diameter, length and shape. The three-point test was carried out in accordance with ISO 10477:2004, using the Instron-5944 testing machine (Instron, Norwood, USA). The test was carried out until the sample was broken.
RESULTS: The highest force values (67.6 N) were recorded for the GC posts, and the lowest force required to break the sample (29.6 N) was noted for the EverStick Posts. In the case of bending strength, the highest values were also recorded for GC posts (912.4 MPa). Low bending strengths were obtained for the Mirafit White posts (537.2 MPa); however, the EverStick Posts were the weakest (436.2 MPa). Rebilda posts showed the highest modulus of elasticity - 31.1 GPa. The lowest values of the elastic modulus were registered for EverStick Posts - 12.5 GPa.
CONCLUSIONS: There were statistically significant differences in fracture loads, flexural strengths and flexural modulus of the FRC-post systems tested. Individually polymerized FRC material showed lower flexural properties than compared prefabricated FRC posts.

BACKGROUND: Dental esthetic materials are constantly introduced to meet the increasing esthetic demand in contemporary dental practice.
OBJECTIVE: To test the fracture resistance of endodontically treated teeth (ETT) restored with different esthetic post materials like fiber-reinforced composite post (FRC), polyether ether ketone (PEEK), and polymer infiltrated ceramic (PIC).
METHODS: Thirty-six human root canal treated single-rooted premolar teeth were decoronated 3 mm above the cemento-enamel junction and prepared to receive the post. They were randomly divided into three groups (n= 12) to be restored with FRC, PEEK, and PIC. After appropriate surface treatment, they were cemented with self-adhesive luting cement and restored with full veneer crowns. The samples were thermocycled, subjected to a compressive static load at 45∘ angulation until fracture. Obtained data were analyzed by one-way ANOVA and Tukey\'s HSD post hoc comparison test.
RESULTS: The results indicate that the ETT restored with PEEK post had the maximum fracture load (1929.94 N), followed by PIC endodontic post group (1810.65N), and FRC post (1715.68N). Meanwhile, ETT restored with FRC showed a predominantly favorable fracture, whereas PEEK restored teeth had a more unfavorable fracture.
CONCLUSIONS: Of all the esthetic post materials, the group for which PEEK endodontic post was used displayed higher fracture resistance.

Trauma with an accompanying fracture to the anterior teeth gives an agonizing experience for a young individual due to the physical disfigurement and the psychological impact that is imposed on them. This paper reports a case of complicated crown-root fracture in a young child that was treated by extra-oral fragment reattachment followed by the intentional reimplantation. The tooth was endodontically-treated followed by the placement of fiber-reinforced composite post. The fragments were reattached extra orally following an atraumatic extraction. The tooth was then reimplanted back into the socket followed by splinting. Clinical results were successful after 2 years. This case report demonstrates the importance of modifying a treatment protocol to maintain esthetics up to the completion of the developmental period.