Core Build-up Materials Research Articles

Comparison of Fracture Resistance among Different Post Placement Strategies and Core Buildup Materials in Endodontically Treated Maxillary Premolars: An In Vitro Study

Comparison of Fracture Resistance among Different Post Placement Strategies and Core Buildup Materials in Endodontically Treated Maxillary Premolars: An In Vitro Study

Comparative Evaluation of Access Cavity Designs and Core Buildup Materials on Fracture Strength in Molars Using CBCT

Comparative Evaluation of Access Cavity Designs and Core Buildup Materials on Fracture Strength in Molars Using CBCT

Comparative Evaluation of Fracture Resistance of Composite Core Buildup Materials: An In Vitro Study.

Aim This study aimed to compare the fracture resistance of different materials used in composite core buildups, including conventional filler composite, nanofiller composite, and short fiber-reinforced composite (SFRC). Methods This in vitro study was conducted on 30 freshly extracted premolars. The teeth were treated using a uniform endodontic procedure, and Fiber Posts (REFORPOST, Angelus) were placed. The teeth were then divided into three groups and restored using different materials. Group 1 was restored using SFRC(everX Posterior, GC, Europe), Group 2 using microfiller composite (Te-Econom Flow, Ivoclar Vivadent), and Group 3 using nanofiller composite (Tetric N-Flow, Ivoclar Vivadent). The restoration materials were then light-cured for 40 seconds. The teeth were placed in a Universal Testing Machine (Instron) and a load was applied with a stainless-steel ball (4 mm diameter) until the tooth fractured. The fracture load for each tooth was recorded, and after the mechanical test, the experimental groups were examined for failure modes. Statistical analysis was performed using SPSS version 21.0 software. A one-way ANOVA test was conducted to compare more than two groups, followed by Tukey's test for post hoc pairwise comparison. Results The mean fracture resistance of the microfiller composite (346.94±44.63) was the lowest among the three groups. When analyzed using Tukey's test at p<0.05, fracture resistance was significantly higher in the SFRC, followed by nanofillers and microfiller composites. Conclusion Due to the increasing demand for aesthetic restorations in recent years, composites have become important in modern restorative dentistry. The development and implementation of composite dental restorative materials rely on a comprehensive understanding of each composite component and consideration of methods for modifying each component. As a result, the findings of this study will be beneficial in determining which material to use based on specific cases.

Comparative Evaluation of Sorption and Solubility of Core Buildup Materials in Different pH Media: An In-Vitro Study.

To evaluate and compare the sorption and solubility of two different core buildup materials in different pH media for periods of one day, one week, and one month. Sixty samples were prepared and divided into Group A (30 resin-based samples) and Group B (30 glass ionomer cement (GIC)-based samples). The sorption and solubility of the different materials were calculated by weighing the samples before and after desiccation and media immersion for periods of one day, one week, and one month. Groups were compared using the Mann-Whitney U test, and for different media, the intragroup significance of the mean difference was performed using the Friedmann test and Wilcoxon signed rank test at a significance level of p<0.05. After immersion for different time periods, the resin-based core buildup material (Core X flow) showed less sorption and solubility as compared to the glass ionomer-based core buildup material (Secure Core Z) for all time periods, with a significant difference seen for a time period of one week and one month and being nonsignificant for a time period of one day. Core X flow had lower sorption and solubility values when compared to Secure Core Z, as per the International Organization for Standardization (ISO) 4049 standards, except for a one-month time period in alkaline media.

A Successful Reinforcement and Restoration of an Already Damaged Post and Core in a Teeth with an Existing Crown That Has Received Endodontic Treatment: 3 Case Reports

Once correctly indicated, endodontic retreatment requires the preservation of dental components. Effective treatment of teeth with severe damage to the structure of the tooth relies not only on successful endodontic treatment but also on timely postendodontic tooth repair after the same endodontic. Furthermore, for teeth with intracanal posts, the evolution of endodontic procedures and materials has decreased the indication of surgical treatment. Underneath an undamaged crown is a typical clinical occurrence of broken coronal tooth structure. The tooth can be repaired with a post and core if the underlying root is in good condition, and then, the crown is refabricated. This article outlines a method for the aforementioned scenario that makes use of the current unbroken crown. The entire crown was later rescued, and a damaged post and core were also discovered in the canal. The retrieved metallic post was re-cemented in the post space then the undamaged crown was adjusted to fit it, and the opposing arch maintained occlusion. Next, a composite resin that can be dual-cured and built up was poured into the crown, molding it to fit onto the broken tooth. As we know, the core buildup material has a property of dual curing that means it can be self-cured as well as light-cured. Hence, we waited and allowed it to get set by itself chemically. Then, after we carefully removed the crown from over it, a brand-new composite resin core was discovered and adhered to the tooth structure after that we light-cured it for complete the setting process. After that, dual-cured core build-up composite resin was used to re-cement the crown to the core. Even after a year of follow-up, the method of strengthening the tooth’s core and restoring it with the current crown was shown to be effective.

Comparative Evaluation of Fracture Toughness and Flexural Strength of Four Different Core Build-up Materials: An In Vitro Study.

To evaluate and compare the fracture toughness and flexural strength of four different core build-up materials. A total of 60 samples were divided into four groups (n = 15) group I: dual cure composite resin reinforced with zirconia particles (Luxacore Z), group II: light cure composite resin (Lumiglass DeepCure), group III: zirconia reinforced glass ionomer cement (GIC) (Zirconomer Improved), and group IV: chemically cure composite resin (Self Comp) respectively. All the core build-up materials were manipulated according to the manufacturer's instructions and poured into the mold. A universal testing machine applied a central load to the specimen in a 3-point bending mode. Fracture of the specimen was identified and the reading was recorded by the universal testing machine. The data were analyzed statistically using one-way analysis of variance (ANOVA) and then compared. Group I showed the highest flexural strength (48.65 MPa) among all the groups while group IV showed the lowest flexural strength (17.90 MPa). Group I showed the highest fracture toughness (99.12 MPa) among all the groups while group IV showed the lowest fracture toughness (36.41 MPa.cm-0.5). When mean flexural strength and fracture toughness values of all four groups were compared by using one-way ANOVA, the compared data was highly significant. Based on the findings of this study, dual cure composite resin was the material of choice in terms of flexural strength and fracture toughness for core build-up material followed by light cure composite resin. The core buildup material serves to strengthen the tooth structure, allowing it to withstand the forces of chewing and preventing the risk of tooth fractures. This material is essential in restoring damaged or decayed teeth, as it provides a stable foundation for further dental work. By reinforcing the tooth structure, the core buildup material ensures that the tooth can function properly and remain healthy for years to come. How to cite this article: Nakade P, Thaore S, Bangar B, et al. Comparative Evaluation of Fracture Toughness and Flexural Strength of Four Different Core Build-up Materials: An In Vitro Study. J Contemp Dent Pract 2024;25(2):191-195.

Mechanical properties and degree of conversion of resin-based core build-up materials and short fiber-reinforced flowable resin-based composite.

To evaluate the degree of conversion (DC), surface hardness (SH), and flexural strength (FS) of resin-based core build-up materials. Core build-up materials used were: MultiCore Flow (MCF); Activa (ACT); Core-X Flow (CXF); and everX flow (EVX), and DC, SH and FS were measured. An increase of DC was identified for all materials post-cure, except for EVX. The DC change percentage ranged from 5%-33%, and EVX was displayed the greatest DC rate. All materials displayed an SH increase after 30 days and the greatest increase was observed in ACT. At 1 h, the SH of EVX and CXF was different from the other materials. At 30 days, MCF displayed the greatest SH. All materials displayed an increase in their FS after 30 days except for EVX, and ranging 3%-36% were noticed. Differences observed between materials, thus clinician should be acquainted mechanical properties of these materials to ensure the success of the restorations.

Effects of glass fibers reinforced and non-reinforced composite resin on fracture behavior of severely destructed primary incisors and restored with post and core system

ObjectiveTo evaluate fracture resistance and failure type of coronally rehabilitated primary incisors with EverX Flow or Grandio Core post and core with or without fiber post. Materials and MethodsForty-eight extracted maxillary primary incisors were root canal treated and obturated with Metapex. The coronal 4-mm of Metapex was removed to create 3-mm intracanal post space. Next, coronal enamel and radicular dentin surfaces were acid-etched, and a bonding agent was applied and light-cured. Based on intracanal post and 2-mm height core buildup materials, specimens were divided equally (n = 12) into 4 groups as follow; Group I (EverX Flow), Group II (Grandio Core), Group III (Fiber post, and EverX Flow), and Group IV(Fiber post and Grandio Core). The coronal restorations were finalized to 4-mm height using G-aenial Anterior composite and specimens were tested for fracture resistance. Force required to induce fracture was recorded and failure type was examined. ResultsFracture resistance of Fiber post and EverX Flow group was statistically significant high than other tested groups. However, fracture resistance of EverX Flow group showed non-statistically significant difference from that of Fiber post and Grandio Core group. Regarding failure type, no specimen presented root fracture, and all failures were favorable and repairable. ConclusionEverX flow post and core with or without fiber post enhanced fracture resistance of restored primary incisors compared to Grandio Core alone. Clinical relevanceEverX flow post and core system with or without fiber post could be a promising restorative option for severely destructed primary incisors.

The influence of core-build up materials on biaxial flexural strength of monolithic strength-gradient zirconia; an in-vitro study

BackgroundSince their introduction, there has been limited research regarding the mechanical properties of novel strength-gradient monolithic zirconia. In addition to that, studies evaluating the effect of different core-build materials on the strength of indirect restorations are scarce. Therefore, the aim of this study was to investigate the effect of using different core build-up materials on biaxial flexural strength of a new monolithic multilayered zirconia material.MethodsForty zirconia discs were fabricated from IPS e.max ZirCAD Prime (Ivoclar Vivadent AG, Schaan, Liechtenstein) and divided into 2 groups (n = 20). Forty composite discs were prepared from Tetric N-Ceram (Ivoclar Vivadent AG, Schaan, Liechtenstein) and MultiCore Flow (Ivoclar Vivadent AG, Schaan, Liechtenstein). The zirconia discs were adhesively cemented to the 2 types of composite forming 2 groups (Zirconia-Tetric N-Ceram and Zirconia-MultiCore Flow). Biaxial flexural strength was determined using a piston-on-3-ball test. The data were statistically analyzed with an independent t-test for significant differences (p = 0.05).ResultsTetric N-Ceram had significantly higher strength than MultiCore Flow (p < 0.001) but no statistically significant differences were found in strength values between Zirconia-Tetric N-Ceram and Zirconia-MultiCore Flow bilayered samples (p = 0.27).ConclusionsIt was concluded that although the tested composite core materials significantly differ in their biaxial flexural strength values, they had no influence on the biaxial flexural strength of the overlying zirconia.

Evaluation of Compressive and Flexural Strengths of Two Resin-based Core Materials with an Alkasite Material: An In Vitro Study.

To compare and evaluate the compressive and flexural strengths of two resin-based core build-up materials with an alkasite material. ParaCore, Tetric N ceram Bulk-fill composite, and Cention N were used. A total of 90 specimens were prepared. Customized cylindrical split molds of dimension 6 ± 1 mm (height) × 4 ± 1 mm (diameter) were used to fabricate 15 samples of each core material for testing the compressive strength and rectangular split metal molds of dimensions 25 ± 1 mm (length) × 2 ± 1 mm (width) × 2 ± 1 mm (height) were used to fabricate 15 samples of each core material for testing the flexural strength. Then the samples were tested using a Universal testing machine (UTM). The compressive and flexural strengths of Cention N were significantly less than ParaCore® but higher than Tetric® N-CeramTM Bulk-fill core build-up material. Within the limitations of this study, it was concluded that Cention N may be used as an alternative to other core build-up materials after further in-vitro and in-vivo studies. Cention N had the added advantage that self-cure polymerization alone was sufficient to achieve good physical properties when compared to the other two resin-based core build-up materials.

Finite Element Analysis of the Mechanical Performance of Non-Restorable Crownless Primary Molars Restored with Intracoronal Core-Supported Crowns: A Proposed Treatment Alternative to Extraction for Severe Early Childhood Caries

Early childhood caries (ECC) involve extensive coronal tooth structure loss, and tooth reconstruction remains highly challenging. To fulfill preclinical assessment, the present study investigated the biomechanics of non-restorable crownless primary molars that were restored by stainless steel crowns (SSC) using different composite core build-up materials. Computer-aided design-integrated 3D finite element and modified Goodman fatigue analyses were performed to determine stress distribution, risk of failure, fatigue life and dentine-material interfacial strength for the restored crownless primary molars. A dual-cured resin composite (MultiCore Flow), a light-cured bulk-fill resin composite (Filtek Bulk Fill posterior), a resin-modified glass-ionomer cement (Fuji II LC) and a nano-filled resin-modified glass-ionomer cement (NRMGIC; Ketac N100) were used as core build-up composite materials in the simulated models. The finite element analysis showed that types of core build-up materials affected the maximum von Mises stress only in the core materials (p-value = 0.0339). NRMGIC demonstrated the lowest von Mises stresses and revealed the highest minimum safety factor. The weakest sites were along the central grooves regardless of type of material, and the ratio of shear bond strength to maximum shear stress at the core-dentine interface of the NRMGIC group was lowest among the tested composite cores. However, all groups provided lifetime longevity from the fatigue analysis. In conclusion, core build-up materials differentially influenced the von Mises stress (magnitude and distribution) and the safety factor in crownless primary molars restored with core-supported SSC. However, all materials and the remaining dentine of crownless primary molars provided lifetime longevity. The reconstruction by core-supported SSC, as an alternative to tooth extraction, may successfully restore non-restorable crownless primary molars without unfavorable failures throughout their lifespan. Further clinical studies are required to evaluate the clinical performance and suitability of this proposed method.

Impact Of Restorative Material On Fracture Strength Of Root Canal Treated Teeth: An In Vitro Study.

There are several materials available in the market for the core buildup of endodontically treated teeth. The purpose of our study is to evaluate the fracture resistance of endodontically treated teeth restored with composite resin, amalgam and glass ionomer cement as core buildup materials. Forty-eight sound-extracted mandibular premolar teeth were randomly divided into 4 groups of 12 teeth each. The first group served as a control and consisted of intact sound teeth. In all of the remaining teeth, root canal treatment was performed first. In Group II composite resin was used as the core build-up material Group III amalgam and Group IV GIC. Teeth were then subjected to fracture using a universal testing machine. One Way ANOVA test was performed to study the differences in the data of the four groups. The mean forces required for fracture were 1050 N for control teeth, 738 N for composite, 872 N for amalgam and 567 N for GIC. The variation is of statistical significance as depicted by a p-value of 0.003. The highest strength was shown by intact sound teeth. Teeth restored with composite resin and amalgam had similar strengths and those with GIC had significantly lower resistance to fracture.

Comparative evaluation of shear bond strength at the interface of monolithic zirconia with two distinct core build-up materials: An in vitro study.

The study aimed to evaluate and compare the shear bond strength (SBS) at the interface of monolithic zirconia with zirconomer (Zr) core build-up, a new type of glass ionomer cement to monolithic zirconia with composite resin core build-up material. In vitro a comparative study. A total of 32 disk-shaped samples of monolithic zirconia and two distinct core build-up materials: Zr (n = 16) and composite resin (n = 16) were used. The two components, monolithic zirconia with Zr core build-up and monolithic zirconia with composite resin core build-up, were bonded using zirconia primer and self-adhesive, dual-cure cement. The samples were subsequently thermocycled, and the SBS was tested at their interfaces. The failure modes were determined using a stereomicroscope. Data were evaluated using the descriptive analysis for mean, standard deviation, confidence interval, and independent t-test for intergroup comparison. Descriptive analysis, independent t-test, Chi-square test. The mean SBS (megapascals) of monolithic zirconia to Zr core build-up (0.74) was statistically significant when compared to monolithic zirconia with composite resin core build-up material (7.25) (P ≤ 0.001). Zirconomer core build-up showed 100% adhesive failure; composite resin core build-up had 43.8% cohesive, 31.2% mixed, and 25.0% adhesive failures. When evaluating the two core build-up materials' bindings to monolithic zirconia, Zr and composite resin core build-up showed statistically significant differences. Although Zr has been demonstrated to be the optimal core build-up material; however, additional investigation is required to determine how it bonds to monolithic zirconia more effectively.

Effect of different indirect composite onlay and core materials on fracture resistance of endodontically treated maxillary premolars.

Purpose To compare and evaluate the effects of different indirect composite onlay and/or core buildup materials on the fracture resistance and fracture mode of restored endodontically treated premolars.Methods Two conventional handmade indirect composite resins (SR Nexco (NC) and Ceramage (CM)) and two core buildup materials, dual-cure composite resin (MultiCore Flow (MC)), and short fiber-reinforced composite resin (EverX Posterior (EXP)), were selected. Sixty maxillary premolars were randomly divided into six groups (n=10). Group 1 included intact teeth (INT; positive control). Mesio-occluso-distal cavity preparation and endodontic treatment was performed on the remaining premolars. Group 2 was restored with polymer-reinforced zinc oxide eugenol intermediate restorative material (IRM; negative control), whereas the experimental groups (groups 3-6) were restored with core buildup material and indirect composite onlay (MC_NC, MC_CM, EXP_NC, and EXP_CM). The specimens received compressive loading using a universal testing machine, at 45° to the long axis with a crosshead speed of 0.5 mm/min until fracture. Fracture modes were visually analyzed. Fracture resistance was measured and statistically analyzed using two-way and one-way ANOVA (α=0.05).Results Only the type of indirect composite onlay affected the fracture resistance of the experimental groups (P=0.009). The MC_CM group showed the highest fracture resistance, which was significantly higher than that of the MC_NC group (P=0.031). No statistically significant differences were found between the INT group and other experimental groups(P>0.05). All groups had a greater incidence of restorable than unrestorable failures.Conclusions The type of indirect composite onlay affected the fracture resistance of restored endodontically treated maxillary premolars.

Effect of Surface Treatments on Adhesion of Milled Polyetheretherketone Post to Different Composite Resin Core Build-Up Materials.

To evaluate the effect of surface treatments on adhesion of milled PEEK post to two different composite resin core-build up materials. Six PEEK posts were divided into the following groups: G1: no treatment+ Grandio core material, G2: no treatment+ Bulk-fill core material, G3: 98% sulfuric acid for 60 seconds+ Grandio core material, G4: 98% sulfuric acid for 60 seconds+ Bulk-fill core material, G5: 50 μm airborne particle abraded + Grandio core material, G6: 50 μm airborne particle abraded + bulk fill core material. The adhesion of the post to core build-up materials was tested using micro push-out bond strength. Data were analyzed using ANOVA and Tukey's test. There was a significant effect for the surface treatment (p<.001), a non-significant effect for the core build-up materials (p<.289), and a significant effect for their interaction (p<.001) on the bond strength values. Within the limitation of this study, sulfuric acid etching group significantly increased the bond strength compared to other groups. Bulk-fill core material could be a feasible option when restoring ETT in terms of saving chair time and the treatment procedure simplicity. Key words:Bond Strength, Core material, PEEK, Surface Treatment.

A Comparative Evaluation of Fracture Resistance in Endodontically Treated Teeth Reinforced by Novel Hybrid Post and with Various Pre-Fabricated Post Techniques: An In-Vitro Study

Introduction: Teeth with a final post-endodontic restoration cannot support significant structural loss brought on by fracture, caries, big pre-existing restorations, or aggressive cavity preparation. Post and core restoration allows for the restoration of such teeth. Reduced dentine size, moisture, and compromise on supporting structures such the oblique bridge, marginal ridges, and pulp chamber roof result in a reduction in their resistance because of structural loss. Under such circumstances, choosing a good post-endodontic restorative material can be difficult. Materials and Methods: In terms of post-treatment procedures, 40 single-rooted decoronated mandibular premolar teeth were endodontically treated and randomly divided into four groups. As a control, the first group had a composite core but no post; groups two and three had prefabricated metal threaded posts; group four had prefabricated hybrid posts. The posts were affixed using dual-cure resin cement, and the core build-up material was nano composite. Each group's core structure was standardised, and metal crowns of the same size were used to reinforce it. A universal testing machine was used to test every specimen, and the fracture load was tabulated. Statistical analysis used: one way ANOVA analysis Results: The highest failure load was found with prefabricated hybrid post. This group had significantly higher load compared to other post groups. Followed by prefabricated fibre post and prefabricated metal threaded post. Conclusions: Fracture resistance of endodontically treated teeth reinforced with hybrid post showed significant values when compared to that of prefabricated glass fiber posts, prefabricated threaded post and control teeth.

Effect of Fluorographene Addition on Mechanical and Adhesive Properties of a New Core Build-Up Composite.

This study aims to develop a restorative material having such mechanical and adhesive properties that it can be used both as a reconstruction material and as a luting cement. The experimental core build-up composite (CBC) was derived from a self-adhesive cement by the modification of its chemical formula, requiring the use of dedicated dentin and ceramic primers. The adhesive properties to zirconia and dentin were analyzed with a micro-Shear Bond Strength test (mSBS). The mechanical properties were analyzed by a flexural strength test. The results were compared with those obtained for other commercially available cements and core build-up materials, both before and after addition of 2 wt.% fluorographene. The CBC obtained average values in the mSBS of 49.7 ± 4.74 MPa for zirconia and 32.2 ± 4.9 MPa for dentin, as well as values of 110.9 ± 9.3 MPa for flexural strength and 6170.8 ± 703.2 MPa for Young's modulus. The addition of fluorographene, while increasing the Young's modulus of the core build-up composite by 10%, did not improve the adhesive capabilities of the primers and cement on either zirconia or dentin. The CBC showed adhesive and mechanical properties adequate both for a restoration material and a luting cement. The addition of 2 wt.% fluorographene was shown to interfere with the polymerization reaction of the material, suggesting the need for further studies.

An In Vitro Study Comparing the Diametral Tensile Strength of Composite Core Build-Up Material With Three Different Prefabricated Post Systems.

Statement of problemDental restorations are subjected to tensile stresses from oblique or transverse loading of their complex geometric forms, making tensile strength a fundamental mechanical property. Since composite core build-up materials are brittle, the integrity of the post and core depends on their tensile strength and resistance to fracture when utilized with various prefabricated post systems. Therefore, it is essential to determine the tensile strength of the prefabricated metallic and nonmetallic posts used to reinforce the composite resin core.PurposeThis study compared the diametral tensile strength (DTS) of three prefabricated post systems with composite core build-up material.Material and methodologyTen composite resin cores from four different groups were formed. The control group was the composite resin core without a post (group 1). Group 2 was composed of composites with metal posts, group 3 was composed of composites with glass fiber posts, and group 4 was composed of composites with carbon fiber posts. All the samples were kept in a humid place for seven days to mimic the conditions in the mouth. DTS was determined by recording the tensile force required to fracture the core material by performing a diametral compression test for tension after a week. The observations were analyzed using a one-way analysis of variance (ANOVA), followed by a post-hoc test.ResultsThe tensile strength of the resin core material was decreased by 28.1%, 20.8%, and 10.4% by using posts made of stainless steel, carbon fiber, and glass fiber, respectively. Among the three post systems, stainless steel had the lowest mean DTS values, while glass fiber had the highest mean DTS values.ConclusionComposite core glass fiber post systems showed higher tensile strength than other post systems.

Release of monomers in dental wastewater during treatment. A comparative in vitro and in vivo study based on Fabric phase Sorptive extraction

The main objective of this research was to detect monomers that are released during dental restorative procedures related to the oral cavity and then discharged into the environment through the drainage of the dental unit. This study involves the collection of wastewater from the spray system of a high-speed dental handpiece before it winds up in the central drain after the grinding of resin composite materials. The study was executed in two phases: an in vitro experiment and an in-vivo experiment. Three representative dental materials were used; a resin composite for direct restorations, a core-build up material, and a computer-aided designand computer-aided manufacturing (CAD/CAM) material. On both occasions, the water from the spray-system of the handpiece during the milling of the specimens was extracted using water suction and analysed by high-pressure liquid chromatography (HPLC) and verified with HPLC-PDA after Fabric Phase Sorptive Extracttion. In the first phase, triethylene glycol dimethacrylate (TEGDMA) was detected in the wastewater samples of all the materials tested whereas bisphenol-A (BPA) was not detected. Urethane dimethacrylate was released only from the CAD/CAM material (0.66 ± 0.14 ng/μL) while BisGMA was not detected. In the second phase the core build-up material released an amount of BPA (0.42 ± 0.14 ng/μL) while after 7 days, the amount of BPA increased (0.97 ± 0.07 ng/μL). The resin composite indicated for direct restoration material released the highest amount of TEGDMA (p < 0.001).The contamination of the environment by dental procedures is possible because monomers are released from different dental restorative materials and are detected in the wastewater of dental units.

Effect of Different Post Materials and Adaptability on Fracture Resistance and Fracture Mode in Human Endodontically Treated Teeth.

Objective To investigate the effect of different post materials and adaptability on fracture resistance and fracture mode of endodontically treated teeth. Materials and Methods Sixty extracted human mandibular premolars were selected and divided into 6 groups (n = 10) according to the restorative method after endodontic treatment: no ferrule presented and restored without fiber post (Group C), 2.0 mm ferrule presented and restored without fiber post (Group CF), restored with D.T. Light-Post (Group PDT), restored with anatomically customized D.T. Light-Post, relined with resin composite (Group ADT), restored with Hi-Rem prosthetic post (Group PHR), and restored with anatomically customized Hi-Rem prosthetic post, relined with resin composite (Group AHR). After restoring with core build-up materials, all specimens were loaded at 45° in a universal testing machine until failure. Visual inspection of all specimens for fracture modes was performed. The data were analyzed using one-way ANOVA, and the fracture mode was reviewed using the chi-square test. Results Anatomically customized groups presented statistically significant higher fracture resistance than prefabricated groups and group C (P < 0.05). Without post, group CF displayed significantly higher fracture resistance than group C (P < 0.05). Group C, CF, PDT, and PHR showed some specimens with unfavorable fractures. Conclusions Anatomically customized posts presented highest fracture resistance among all groups. There was no significant difference in fracture mode across all groups.