Fiber-reinforced Composite Resin Research Articles

A sectional precontoured metal matrix to improve the pontic contour and emergence profile for fiber-reinforced composite resin fixed dental prostheses

Fixed dental prostheses made with fiber-reinforced composite resin are a conservative and cost-effective option for replacing a missing tooth.1 This type of prosthesis can be fabricated directly or indirectly,2,3 but the direct technique is challenging and susceptible to error; in addition, shaping the pontic is difficult.4

Study on the heterogeneous material coupling connection characteristics and mechanical strength of Oratosquilla oratoria mantis shrimp saddle.

The microstructure, chemical composition and mechanical strength of heterogeneous materials of mantis shrimp (Oratosquilla oratoria) saddle were studied. As the key component of the striking system, the saddle comprised two distinct layers including outer layer and inner layer. The outer layer contained blocky microtubules and exhibited compact appearance. The inner layer presented a typical periodic lamellar structure. Due to the change of the thickness of the mineralized outer layer, the organic multilamellar structure became the foundation and enhanced the connection strength (4.55 MPa) at the connect regions between the saddle and merus exoskeleton and membrane, respectively. In the process of fracture, the lamellar structure dispersed the stress effectively by the change of the crack deflection direction and the microfibrils ordered arrangement. The exploration of mantis shrimp saddle region is beneficial to understand the striking system and provided the possibility for the stable connection of heterogeneous materials in engineering fields. The microstructure, heterogeneous material connection characteristics and high mechanical strength of saddle provide bionic models for the preparation of fiber-reinforced resin composites and soft composites.

Can fiber-reinforced resin composites alone substitute adhesively luted intraradicular post and core materials under static and dynamic loading?

This study investigated the load bearing capacity of intraradicular posts and core materials under static and dynamic loading. Human teeth with single root (N = 154, n = 14 per sub group) were endodontically prepared and randomly divided into six groups: CON: Sound premolars; TP: Titanium post (Flat Head T); FRCP: Indirect E-glass FRC post (FRC Postec Plus); FRCC: Fiber-reinforced resin composite (Everex Posterior) as post and core; RCW: Hybrid composite (Tetric) as post and core with woven fiber network (EverNet) between root canal and core; RC: Hybrid composite (Tetric) as post and core material. Groups TP, FRCP were luted adhesively in the root canal (Panavia 21), while other groups were bonded directly to the intraradicular dentin. In groups TP, FRCP, RCW, core material was hybrid composite. The teeth were then restored with CAD/CAM resin composite (ArtBlock Temp). While half of the specimens in each group were fractured after 4 weeks water storage, the other half was subjected to chewing simulation (x1.200.000; 5–55 °C). Data for F initial (N) and F max (N) were analyzed using 2-way ANOVA and Tukey’s tests (alpha = 0.05). Fracture strength values were significantly affected by the post and core type (p < 0.05) and the fatigue conditions (p < 0.05). After cyclic loading, F initial values were significantly lower for TP (222.70) and RCW (238.60), compared to other groups (335.50 − 377.20) (p < 0.05) and F max was significantly lower for RCW (742.11). TP group presented mainly cohesive failure in the crown material with adhesive detachment from the post core and other groups showed predominantly irreparable failures.

An in vitro study to compare the influence of two different primers on the peel bond strength between a maxillofacial silicone material and an acrylic resin material versus a composite resin material.

Aim:The aim of this study was to evaluate and compare the peel bond strength of an autopolymerizing acrylic resin and a fiberreinforced composite (FRC) resin to a heat temperature vulcanizing maxillofacial silicone (M511) using two different primers.Settings and Design:In vitro - comparative study.Materials and Methods:Autopolymerizing acrylic resin and FRC resin specimens with a dimension of 75 mm (length) ×10 mm (width) × 3 mm (height) were fabricated. A total of 60 samples were split into six categories based on the substructure material and primers (A330G primer and Sofreliner tough primer) used to bond the maxillofacial silicone to the FRC and acrylic resin specimens. In a universal testing machine, the peel bond strength was conducted at a 10 mm/min crosshead speed until bonding failure occurred.Statistical Analysis Used:The t-test, one-way analysis of variance, and the Tukey's honest significant difference (post hoc test) tests were used to statistically assess the values.Results:The Sofreliner tough primer produced the greatest peel bond strength in both the acrylic resin (0.89690 N/mm) and the FRC resin groups (3.19860 N/mm). Adhesive failures predominated in the acrylic resin group regardless of the primer used. The FRC group showed predominantly cohesive failures with both the A330G primer and Sofreliner tough primer.Conclusion:This study suggests that FRC resin combined with Sofreliner tough primer can significantly enhance the peel bond strength.

Comparison of fiber-reinforced composite and nanohybrid resin impregnated with glass fibers as postendodontic restoration in molars – A clinical study

Background:Restoration of endodontically treated teeth is one of the most challenging part of operative dentistry. The introduction of fiber-reinforced composite has provided a considerable opportunity to modify material's behavior and to enhance the response of existing materials.Aim:The aim of the study is to comparatively evaluate the efficacy of fiber-reinforced composite resins and nanohybrid resin impregnated with glass fibers as postendodontic restoration in molars.Materials and Methods:Fifty patients with deep occlusal carious lesion requiring root canal treatment were selected and treated. For postendodontic restoration, it was divided into Group A (Interlig) and Group B (ever-X posterior) which were eventually restored according to the manufacturer's instructions. Patients were recalled for evaluation at 3-, 6-, 12-month interval. The restorations were evaluated according to modified United States Public Health Service Criteria.Statistical Analysis:Chi-square test was used for intergroup comparison.Results:A statistically significant difference was noted in terms of fracture of tooth and ever-X posteriors proved to be a superior material and no statistically significant difference observed for marginal discoloration, marginal integrity, fracture of core-build up and secondary caries at the evaluation period of 1 year.Conclusion:Ever-X posteriors performed better than Interlig group as postendodontic restoration after 1 year of evaluation.

Stress Distribution in Maxillary Central Incisors without Ferrules: A Finite Element Analysis of Post and Core Systems

Purpose: The purpose of this study was to identify optimal post and core materials for central incisors without ferrules using three-dimensional finite element analysis and three-point bending tests. Methods: Stress analyses were performed with six models: cast metal post and core (MP), composite resin core alone, straight fiber-reinforced post-composite resin core (FSR), tapered fiber-reinforced post-composite resin core, straight titanium post-composite resin core (TSR), and tapered titanium post-composite resin core (TTR). A 100-N load was applied to the lingual surface at a 45° angle to the long axis of the tooth. Maximum von Mises stress distributions were calculated with finite element analysis software. Five samples each of composite resin, straight fiber-reinforced post, straight titanium post, straight fiber-reinforced post and composite resin, and straight titanium post and composite resin were subjected to three-point bending tests, followed by analysis of variance and Tukey’s multiple comparison test. Results: Stress distribution was optimal on TTR. Maximum von Mises stress on the cervical side of the post was greatest in TSR (693 MPa) and TTR (556 MPa). Maximum stress on the apical side of the post was greatest in MP (110 MPa). Maximum stress in surrounding dentin was lowest in MP (203 MPa) and TTR (250 MPa). Gap distance was smallest in MP (0.09 mm) and largest in FSR (0.26 mm). Mean maximum three-point bending force was lowest in composite resin (26.9 N/mm) and highest in titanium post and composite resin (97.1 N/mm). Titanium post bending strength was consistently greater than that of the fiber-reinforced post (p < 0.01). Conclusion: These results revealed optimal stress distribution and high bending strength with the tapered titanium post and resin combination, suggesting that this combination can most effectively prevent root or post fracture in an anterior tooth without a ferrule.

Physical and mechanical characteristics of short fiber-reinforced resin composite in comparison with bulk-fill composites.

The objective of this study was to evaluate the physical and mechanical properties of a short fiber-reinforced resin composite: everX-Posterior and compare it with two bulk-fill composites, namely, Filtek Bulk-fill and Beautifil-Bulk, which are intended for large posterior restorations. Investigated properties were flexural strength, flexural modulus, surface roughness, volumetric shrinkage and depth of cure. Scanning electron microscopy images of each specimen after the flexural test were used for cross-sectional comparison. Results were analyzed using ANOVA following Tukey post-hoc test. Flexural strength of everX-Posterior was comparable with two other resin composites, showing higher flexural modulus. EverX-Posterior showed the highest surface roughness after polishing and the lowest volumetric shrinkage (2.29%) among all composites used in this study. Data also showed that the everX-Posterior depth of cure was 4.24 mm, which was the highest among the three groups. Based on the results of this study, it was concluded that everX-Posterior as a short fiber-reinforced composite showed improvements and satisfactory performance in mechanical and physical properties, which make it a reliable base material candidate for large posterior restorations.

Splinting of the Anterior Maxillary Teeth Using Glass-Ceramic Materials: A Case Report

Objective:The aim of this study was to present the technique of splinting anterior maxillary teeth using heat-pressed glass-ceramic material in a clinical case with long-term follow-up.Clinical Considerations:Various materials, including fiber-reinforced tapes, glass fibers, composite resin, and partial coverage metal frameworks, have been used as splinting materials with encouraging clinical results.Conclusion:As shown in the presented case, glass-ceramic heat-pressing materials can be used successfully for the splinting of anterior teeth.

Improvements of mechanical and tribological properties of carbon fiber reinforced composites via chemically grafting MA onto MnO2 nanosheets as interphase

To intensify the interfacial properties between carbon fiber (CF) and resin without sacrificing fiber, a new type of carbon fiber reinforced resin composite was designed and fabricated with MnO2 nanosheets and melamine (MA) as interphase. The MnO2 nanosheets were uniformly grown on the carbon fiber via hydrothermal method. And then MA was grafted on the MnO2 nanosheets to from chemical bond with resin by a simple bath shock method. The experiment results show that the flexural and tensile strength of the composite reinforced by CF-MnO2-MA increased by 24.1% and 14.5% compared to that of CF, respectively. And the wear rate is reduced by about 29.6%. In summary, the improvement of mechanical and frictional properties of the composite is related to the synergetic reinforcement in mechanical interlocking and chemical bonding of MnO2 nanosheets and MA.

Nanofibrillated Bacterial Cellulose Modified with (3-Aminopropyl)trimethoxysilane under Aqueous Conditions: Applications to Poly(methyl methacrylate) Fiber-Reinforced Nanocomposites.

The development of eco-friendly fiber-reinforced composite resins is an important objective from an environmental perspective, and nanofibrillated bacterial cellulose (NFBC), with extremely long high-aspect-ratio fibers, is a filler material with high potential for use in such composite resins. In this study, we investigated chemical modification of the surfaces of NFBC fibers by coupling with (3-aminopropyl)trimethoxysilane and fabricated nanocomposite materials using the prepared surface-modified NFBC. The product prepared by the one-pot reaction of (3-aminopropyl)trimethoxysilane with NFBC microfibrils dispersed in aqueous acid retained the same nanofibril structure as the intact NFBC. The degree of molar substitution and the silicon states on the surface of the product depended on the NFBC/(3-aminopropyl)trimethoxysilane ratio. The thermal analysis revealed that the thermal degradation temperature of the products increases with an increase of degree of molar substitution. Highly transparent (78–89% at 600 nm) poly(methyl methacrylate)-based nanocomposites were prepared by solvent casting; the nanocomposite containing 1.0 wt % (3-aminopropyl)trimethoxysilylated NFBC was only 8% less transparent than neat poly(methyl methacrylate) at 600 nm. In addition, the tensile strength of the nanocomposite was more than twice that of neat poly(methyl methacrylate) when 1 wt % of the surface-modified NFBC was added. The surface-modified NFBC is expected to be a reinforcing nanofiber material that imparts excellent physical properties to fiber-reinforced resins.

Effect of Fiber-Reinforced Composite and Elastic Post on the Fracture Resistance of Premolars with Root Canal Treatment—An In Vitro Pilot Study

(1) Background: To analyze the fracture resistance of endodontically upper premolar teeth restored with glass fiber reinforced posts, glass fiber elastic posts, conventional composite resin (CR) and glass fiber reinforced composite (FRC) resins as restorations. (2) Methods: Seventy premolars were submitted to root canal treatment and restored with the following restorative materials (n = 10): A. FRC posts restored with resin; B. Elastic FRC posts restored with resin; C. FRC posts restored with FRC resin; D. Elastic FRC posts restored with FRC resin; E. Direct restoration with resin; F. Direct restoration with FRC resin; G. Untreated teeth. The teeth were embedded in an epoxy resin model, thermal cycling fatigued in distilled water and mechanical cycling fatigued inducing 80 N load. Loading was applied axially on the center of the occlusal surface with a vertical displacement. The fracture was produced by a universal machine at a crosshead speed of 0.5 mm/s with a 5000 N load cell. The results were analyzed by ANOVA and Tukey’s test and Weibull characteristic strength and modulus were calculated. (3) Results: The group that obtained the greatest fracture resistance was D (3620 ± 470 N) and the least resistant was group A (2420 ± 1010 N). Statistically significant differences were observed between the groups restored with Elastic FRC posts-CR versus FRC post-CR and only CR (p = 0.043 and p = 0.008). (4) Conclusions: The glass fiber reinforced restorative materials increase the fracture resistance of endodontically treated teeth.

Study on Thermal Conductivity of Carbon Fiber / Resin Composite Modified with Graphene Nanoplatelets

A method for calculating thermal conductivity of graphene/carbon fiber reinforced resin composites (GnP-CFRP) was established basing on the Mori-Tanaka program in the DIGIMAT software. The influence of grapheme nanoplatelets (GnP) on the thermal conductivity of composites has been simulated and experimentally verified. The results show that the thermal conductivity of GnP-CFRP increased with the increase of GnP content, and when the GnP content is too high, the increasing rate of thermal conductivity decreases gradually. In addition, the maximum prediction error of the simulation calculation method in this paper is within 7.27%, which is in good agreement with the actual situation.

Evaluation of physical properties of fiber-reinforced composite resin

ObjectivesThis study aimed to investigate physical properties of a fiber-reinforced CAD/CAM resin disc, which included woven layers of multi-directional glass fibers. MethodsFiber orientations of CAD/CAM specimens (TRINIA, SHOFU) were specified as longitudinal (L), longitudinal-rotated (LR), and anti-longitudinal (AL). A fiber-reinforced composite (everX posterior, GC (E)) and a conventional composite (Beauti core flow paste, SHOFU (B)) were also tested.A three-point bending test and a tensile test with notchless prism-shaped specimens were conducted using a universal testing machine (AUTOGRAPH AG-IS, Shimadzu). A water absorption test was also carried out after the specimens were stored in water for 24h or 1 week. Flexural strength and fracture toughness were obtained by conducting a three-point bending test. ResultsTRINIA L and LR groups showed significantly high flexural strength (254.2±22.3 and 248.8±16.7MPa, respectively). Those were approximately 2.5 times higher than those in AL, E, and B groups (96.8–98.0MPa) (p<0.05, ANOVA and Tukey HSD test). No significant difference was shown in flexural modulus among the experimental groups. The fracture toughness in L group (9.1±0.4MPa/m1/2) was found to be significantly higher than those in other groups (1.9–3.0MPa/m1/2; p<0.05). TRINIA group demonstrated significantly lower water absorption (4.7±1.9μg/mm3) than did E (16.1±3.1μg/mm3) and B (17.3±3.7μg/mm3) groups (p<0.05). SignificanceTRINIA demonstrated distinct anisotropy. TRINIA can be used as a superior restorative material when specifying directions of its fiber mesh layers.

Compressive Strength of Dental E-Glass Microfiber-Reinforced Composite Resin in Mouthwash Immersion

Fiber-reinforced composite resin (FRC) is gaining popularity as dental filling material. In the oral cavity, it will contact with the oral environment including oral cleansing agents. This research was aimed to determine the effect of mouthwash on the compressive strength of FRC. The materials used were E-glass FRC (EverX Posterior, GC Corp, Japan), alcohol mouthwash (Original Listerine, Johnson&amp;Johnson, Indonesia), alcohol-free mouthwash (Listerine Cool Mint Zero, Johnson&amp;Johnson, Indonesia). Forty-five FRCs were made in cylindrical shapes. Specimens were divided into 2 groups of mouthwash immersion: alcohol and alcohol-free mouthwash. The groups were sub-grouped by 0, 6, 12, and 24 h immersion. Samples were recorded for compressive strength by Universal Testing Machine. The data were analyzed by ANOVA. The result of compressive strength values (MPa) were (alcohol mouthwash): 293.59±30.54 (0 h), 284.43±46.91 (6 h), 268.71±44.66 (12 h), 252.19±31.49 (24 h); (alcohol-free mouthwash): 294.12±28.17 (0 h), 287.30±35.56 (6 h), 273.32±41.94 (12 h), 260.82±40.67 (24 h). Statistical analysis revealed there was no significant influence of mouthwash type (alcohol or alcohol-free mouthwash), immersion duration (0, 6, 12, 24 h), and combination of mouthwash type and immersion duration (p&gt;0.05) to the compressive strength of FRCs. The conclusions were the mouthwash types, immersion duration, and combination of mouthwash type and immersion duration did not influence the compressive strength of E-glass FRC

Modeling of water wicking along fiber/matrix interface voids in unidirectional carbon/vinyl ester composites

Void formation at the fiber/matrix (F/M) interface is known to be a primary structural defect in a composite material. It is a major factor that contributes to the water uptake in composite materials for underwater applications. We develop a mathematical model to describe the kinetics of water uptake in unidirectional fiber reinforced resin composites containing voids. By using a one-dimensional two-phase fluid flow model with parameters derived from Microcomputed X-ray tomography (µCT), we predict the water wicking process in carbon/vinylester (CF/VE) panels containing capillary voids at the F/M interphase. The capillary driven flow is impeded by viscous forces and the compressed air bubble, trapped between the two flow fronts. In particular, our calculation indicates that the effective contact angle at the F/M interface in CF/VE composite is 29.7 ± 0.1° for the equivalent capillary radius of 1.2 µm. The results are validated by comparing the simulated water absorption to the experimental data for CF/VE composite specimens of three different sizes immersed in sea water.

Clinical success of fixed space maintainers: Conventional band and loop versus fiber-reinforced composite loop space maintainer

Aim: The study aimed to compare the clinical efficacy of two fixed space maintainers and conventional band and loop and fiber-reinforced composite resin (FRCR) space maintainers. Subjects and Methods: Thirty healthy children, aged 6–8 years were selected having at least two deciduous molars in different quadrants indicated for extraction or lost previously. Band and loop space maintainer was cemented in one quadrant, and in the other quadrant, FRCR space maintainer was placed. All the patients were recalled at the 1st, 3rd, 6th, and 9th months, and retention of both the types of space maintainers was evaluated. Statistical Analysis Used: The observations thus obtained were subjected to the statistical analysis using the ANOVA test and post-hoc Tukey test. Results: The retention of the FRCR space maintainer was found to be superior to that of the band and loop space maintainer, and this difference was statistically significant. Conclusion: FRCR (Ribbond) space maintainers can be considered alternative to the conventional band and loop space maintainers.

Fracture strength of dual-structured CAD/CAM restoration with fiber-reinforced composite resin

Fracture strength of dual-structured CAD/CAM restoration with fiber-reinforced composite resin

Comparative Evaluation of Short Fiber-reinforced Composite Resin Thickness on Fracture Resistance of Class II Composite Restoration: An In Vitro Study

This study aims to evaluate the difference in fracture resistance of the short fiber-reinforced composite (SFRC) thickness as intermediate layer of class II composite restoration. Thirty human maxillary premolars were selected and divided into three groups. In groups I, II, and III, class II cavities were prepared. Groups I and II were restored with 2 mm and 4 mm thickness of SRFC as intermediate layer. Group III as control group was restored with nanohybrid composite. Thermocycling procedure was performed manually 250 times. Fracture resistance was measured by using Universal Testing Machine. Data were analyzed statistically using One-way Analysis of Variance (ANOVA) and post hoc least significant difference (LSD) test. The result showed that group II had the highest fracture resistance and group III had the lowest fracture resistance. The difference between groups was statistically significant (p value < 0.05). The conclusion showed that adding 4 mm of SFRC as an intermediate layer increased the fracture resistance. The use of SFRC as intermediate layer enhanced the fracture resistance of class II composite restoration.

Comparison of translucency and flexural strength of fiber-reinforced composite resin materials

Aim: The purpose of this study was to compare translucency values and flexural strength of composite resin materials reinforced with two different fibers.Materials and Methods: In this study, two direct composites (Clearfil Majesty Esthetic and Posterior) and an indirect composite (Tescera) used with a non-fiber control group and two fiber-reinforced (EverStick glass fiber and Ribbond polyethylene fiber) composite groups. Thirty specimens were obtained from the entire composites with dimensions of 25×2×2mm3. Translucency parameter values of the specimens were obtained using a spectrophotometer. The flexural strength (MPa) of the specimens was then determined by a three-point bending test at a rate of 1 mm/min until fracture occurred in the specimen using a universal tester. Data were analyzed by Two Way ANOVA and Tukey HSD multiple comparison test (α=0.05).Results: Ribbond group showed similar translucency parameter values with the control group in all composite materials, but the EverStick group showed significantly lower than the control group (p 0.001). The highest mean flexural strength values were seen in the Clearfil Majesty Posterior control group, while the lowest values were seen in the Clearfil Majesty Esthetic Ribbond group. The mean flexural strength values of the control groups for each composite were found statistically significantly higher than the fiber groups.Conclusion: The fiber addition to composite resins may affect the optical and mechanical properties of the restoration. This effect varies depending on the structural properties of composite resin and fiber. This situation should be taken into consideration in the restoration.

Mechanical properties of fiber-reinforced composite resin exposed to alcoholic beverage

Addition of fiber to dental bridgework was thought to be more efficient comparing to porcelain-fused to metalwork. In other side, some patients consumed alcoholic beverage in their daily life. This study aimed to determine mechanical properties of fiber-reinforced composite (FRC) exposed to alcoholic beverage. The materials used were dental resin (i-FLOW i-dental, Lithuania), polyethylene fiber (Vactrise, USA), and 4 alcoholic beverages. FRC samples (40) were divided into 10 groups (n=4, control:aquades). Each Sample was soaked in beverage for 5 s followed by 5 s in aquades for each cycle (10 cycles daily for 4 wk). Mechanical properties were examined for hardness and flexural strength. The result showed the mean values for hardness (KHN) were: 98.70±6.03 (aquades), 99.01±4.92 (Beer), 87.65±7.83 (Vermouth), 80.23±5.22 (Rum), 78.20±3.70 (Tequila); while for flexural strength (MPa) were: 336.00±25.05 (aquades), 308.25±10.39 (Beer), 215.07±34.86 (Vermouth), 194.89±27.69 (Rum), 175.48±33.58 (Tequila). The ANOVA revealed significant differences in hardness and flexural strength (p&lt;0.05). The LSD showed no significant difference in hardness and flexural strength of FRC soaked in aquades and Beer, while for other groups and aquades the differences were significant. In conclusion, FRCs soaked in different concentration of alcoholic beverages affected the decrease of hardness and flexural strength properties.