Effect of surface conditioning methods,adhesive systems and resin composite on repair strength of dimethacrylate and silorane resin composites

This study evaluated the effect of surface conditioning methods and adhesive systems on the repair bond strength of resin composites. Specimens (FLS: Filtek LS) (N = 144) were prepared using a silicone matrix. The specimens were stored in distilled water and then were randomly divided into the twelve groups (n = 12) according to the surface conditioning method (unground or diamond bur) and adhesive system (no adhesive, LS: Filtek LS, AS: Adper Scotchbond SE Plus) and resin composite (FLS: Filtek LS; FS: Filtek Supreme). The specimens were fixed in an hourglass-shaped silicone matrix and the other half of the specimen was restored. Hourglass-shaped specimens (n = 12) were used as positive control to measure the cohesive strength of the resin composite (Filtek LS). Microtensile bond test was performed (0.5 mm/min) and failure types were analyzed. Data were analyzed using two-way analysis of variance, Tukey’s and Dunnett’s tests (α = 0.05). Adhesive protocol and resin composite significantly affected the results (p < 0.05). For the FS composite, the highest results were obtained using LS adhesive with (18.4 ± 7.7) and without (18.8 ± 4.8) bur roughening. For FLS composite, the highest results were obtained using AS adhesive with (33.2 ± 7.1) and without (25.7 ± 3.6) bur roughening. Without the use of adhesive resin, significantly lower bond strength results were observed with both LS (5 ± 2.1, 4.5 ± 1.5) and FLS (2.2 ± 1.2, 4.4 ± 1.1) for unground and diamond bur roughened groups, respectively (p < 0.0001). Cohesive strength of the FLS (52.3 ± 7.6) was significantly higher than any of the repaired groups (p < 0.0001). FS–LS combination and the groups repaired without adhesive presented more adhesive (Type I) failures.     

The shear bond strength of repaired high-viscosity bulk-fill resin composites with different adhesive systems and resin composite types

This study compared the effect of different adhesive systems and composite resins on the shear bond strength (SBS) of repaired high-viscosity bulk-fill composites(Tetric EvoCeram Bulk Fill) and investigated failure modes. One hundred twenty cylindrical bulk-fill composite blocks (diameter 5?mm) were fabricated and thermocycled for 5000 cycles (5–55?°C). Specimens were roughened by diamond bur and divided into 8 groups (n?=?15). Bulk-fill blocks were repaired with the same material or nanohybrid composite resin(Tetric EvoCeram Nanohybrid) (diameter 3?mm) using different adhesive systems:Tetric N-Bond Universal (TSE);37% phosphoric acid etching?+?Tetric N-Bond Universal (TER); Clearfil SE Bond (CSE); 37% phosphoric acid etching?+?Adper^TMSingle Bond 2(SB). After repair procedures, all specimens were thermocycled again. The shear bond strengths were measured for all specimens using a universal test machine (crosshead speed of 1?mm/min). Cohesive strengths of bulk-fill composites were measured and described as control group. Debonded surfaces were observed with a stereomicroscope under 10x magnification to determine mode of failure. The SBS data of all groups was statistically analyzed by two-way ANOVA and Bonferroni correction test (p?<?0.05). The specimens repaired with bulk-fill composites showed significantly higher SBS values (25.86?±?5.74, 27.05?±?4.93, 24.49?±?6.95MPa) than those with nanohybrid composites (20.41?±?3.70, 22.08?±?6.37, 18.74?±?6.40?MPa) for TER,CSE,SB, respectively (p?<?0.05). There were no significant differences in SBS according to the type of adhesive systems for both repair materials (p?>?0.05). The predominant mode of failure was a mixed type in the restorative material except for the ones repaired with nanohybrid composites using Adper^TMSingle Bond 2. High-viscosity bulk-fill composites could be successfully repaired with the same materials. SBS of repaired bulk-fill composites reached cohesive strength for all tested groups.     

Bond strength of repaired composite resins: surface treatments,adhesive systems,and composite type

The aim of the present study was to investigate the effects of three different surface treatments and two different adhesives on the microtensile bond strength (μTBS) of repaired composites using the same or different type of resin. Twenty-four nano-hybrid (Ceram X mono-C) and 24 nanofilled (Filtek Ultimate-F) composite discs were prepared. The specimens were aged with 5000 thermocycles and randomly divided into groups according to the surface treatment methods: (a) phosphoric acid (b) Er:YAG laser and (c) aluminum trioxide particle (air abrasion). Fresh composite resins (C and F) were added to the treated surfaces with two different adhesives (two-step and one-step self-etch adhesives). Then, the specimens were aged again. The stick-shaped specimens were prepared from the discs (n = 25) and the sticks were subjected to the μTBS test. Results indicated that significant differences were found in μTBS values among the surface treatment methods. In the C groups, the highest μTBS value (41.3 ± 8.3 MPa) was recorded in the air abrasion and one-step self-etch adhesive group, which were repaired with the same kind of composite. In the F groups, the highest μTBS value was observed in the air abrasion and one-step self-etch adhesive (37.6 ± 12.3 MPa) group. The treatment with air abrasion is more effective than the others, and it may be suggested for composite repair.     

Development and status of resin composite as dental restorative materials

Dental composites are comprised of a polymerizable matrix and reinforcing fillers that can be hardened into a solid restoration in the prepared tooth cavity. Composites are becoming increasingly popular due to their esthetics and improved mechanical and physical properties. However, dental composites still encounter several problems, mainly secondary (recurrent) caries, restoration fracture, excessive wear, marginal degradation, and tooth sensitivity. Therefore, extensive efforts are underway to improve the composite compositions and microstructure, and enhance their clinical performance and longevity. Relying on advances in materials science and technology, dental composites have been continuously improved and their clinical applications have been expanded. In this review article, the development of dental composites was summarized, including compositional changes, performance improvements in key areas, current research hot spots, and outlook for future direction. The intention is to provide a review of the history and development of dental composites with a discussion of strategies on addressing the current challenges facing dental composites. In addition, this review will provide a better understanding of dental composites and their properties for the practicing clinicians, to contribute to improving the quality of composite restorations. The review of literature indicates that while current composites are generally bio-inert and can replace the missing tooth structure, future composites should be bioactive and therapeutic to inhibit caries, modulate biofilms, and protect the surrounding tooth structures, in order to increase the restoration longevity. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48180.     

Polymerization shrinkage/stress and dentin bond strength of silorane and dimethacrylate‐based dental composites

This study was designed to determine whether a new dedicated adhesive system using a silorane composite exhibits better bonding performance to human dentin than conventional dimethacrylate‐based composites. The materials were used included: Adper? Easy Bond‐Z250 (AE‐Z250), iBond‐Venus (IB‐VE), XenoIII‐TPH (XE‐TPH), Clearfil S3‐Clearfil Majesty (S3‐CM), and the Filtek silorane system (SA‐FS). Polymerization volumetric shrinkage and stress development were measured using a micro‐CT instrument and universal testing machine. The push out strength of the bonds produced using the corresponding self‐etching adhesive systems were also measured. The volumetric shrinkage of the resin composite/adhesive combinations ranged from 1.05% (SA‐FS) to 3.38% (XE‐TPH) 30 min after light curing. SA‐FS had the lowest volumetric shrinkage (P < 0.05), followed by S3‐CM, EA‐Z250, IB‐VE, and XE‐TPH. The polymerization stress of the materials ranged from 1.54 (SA‐FS) to 3.49 MPa (S3‐CM). The lowest stress was also observed in SA‐FS at 30 min during the stress test (P < 0.05). Push‐out bond strength testing revealed that IB‐VE had significantly lower bond strength than other combinations (P < 0.05). The silorane composite and dedicated adhesive system exhibited excellent characteristics of low volumetric shrinkage and stress development compared to conventional dimethacrylate‐based composites. However, the silorane composite resin system possessed similar push‐out bond strength as the other materials, with the exception of the Venus/iBond combination. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Microtensile bond strength of composite-to-composite repair with different surface treatments and adhesive systems

Objectives: The purpose was to investigate the effect of different surface treatments and bonding agents on the repair bond strength of different resin-based restorative materials by microtensile bond strength (μTBS) testing protocol. Materials and Methods: 24 Grandio SO(VOCO) and 24 Filtek Z250(3?M) resin composite blocks were prepared. Half of the samples (N?=?12) were diamond bur-roughened and the other half (N?=?12) were sandblasted by 50?μm aluminum oxide particles. They were further divided into four sub-groups (n?=?3) and received the following: Sub-Group1: Adper Single Bond2 (Etch&Rinse) (3?M); Sub-Group2: Clearfil SE (Self-etch) (Kuraray); Sub-Group3: Beauty Bond (HEMA-free all-in-one) (Shofu); Sub-Group4: All Bond3 (HEMA-free, hydrophobic, etch&rinse) (Bisco). The samples were repaired by Filtek Z250 to form a block. All of the resultant sub-groups combinations consisted of one of the composite type, surface treatment type, and adhesive systems. A total of 18 groups were prepared including 2 homogeneous blocks. They were thermocycled and μTBS measurements were performed. Data were statistically analyzed with Kruskall–Wallis and Mann–Whitney U tests. Results: The experimental regroups’ μTBS reached to 34.67–66.36% and 43.44–95.52% of the cohesive bond strength for Grandio SO and Z250, respectively. The pre-existing composite type is found to be statistically important. When the surface is bur-finished Grandio performed better; when air-abrasion is considered Z250 showed higher bond strength. All-in-one adhesive system produced the weakest bond strength at all parameters. Conclusion: It may be suggested that when the pre-existing composite is unknown, air-abrasion may be performed with etch&rinse or two-step self-etch adhesives.     

Effect of aging type and aged unit on the repair strength of resin composite to feldspathic porcelain in testing microtensile bond strength

The aim of the present study is to investigate the effect of aging type (thermocycling vs. water storage) and aged unit (block vs. stick) on the repair strength of resin composite to feldspathic porcelain in testing microtensile bond strength (μTBS). Ceramic specimens (N = 30) (10 × 5.7 × 4.5 mm³, Vita Mark II, Vita) were obtained from CAD–CAM blocks. One surface was etched with 10% HF and silanized. An adhesive was applied and resin composite blocks were constructed incrementally on the conditioned surface. The specimens were randomly divided into five groups (n = 6): Control (C): Non-aged; BTC: Blocks were thermocycled (5–55 °C, 6000 cycles); STC: Sticks were thermocycled; BS: Blocks aged in water storage (6 months) after themocycling; SS: Blocks aged in water storage (6 months) after thermocycling. After μTBS test, failure types were classified. Data (MPa) were statistically analyzed (1-way and Dunett and 2-way ANOVA, Tukey`s) (α = 0.05). Two-parameter Weibull distribution values including the Weibull modulus, scale (m), and shape (0) values were calculated. Aging type (p = 0.009) and aged unit (p = 0.000) significantly affected the results. Interaction terms were also significant (p = 0.000). Considering the stick level, there was no significant difference between thermocycling (STC: 25.7 ± 2.3) and water storage (SS: 25.3 ± 3.8) (p > 0.05) but the results were significantly higher when blocks were thermocycled (BTC: 31.6 ± 2.9) (p < 0.05). Weibull modulus and characteristic strength was the highest in BTC (m = 4.2; σ_o: 34.4) among all other groups (m = 3–3.9; σ_o: 14.6–28.5). Adhesive failures were common and cohesive failures occurred in less than 5% in all groups. Aging protocol was detrimental on durability of repair strength of resin composite to feldspathic porcelain. Exposing the sticks to either thermocycling or water storage aging should be considered in in vitro studies.     

Shear bond strength of bis-acryl resin provisional material repaired using a flowable composite

This study investigated the shear bond strength of a bis-acryl composite repaired with a flowable composite after different surface treatments. Sixty standardized cylindrical silicone molds were filled with bis-acryl resin provisional material and then divided into six groups (n = 10 per group) to undergo different surface treatments. After a surface treatment had been performed, the flowable composite was injected directly into the cylinder of each specimen, and the specimens were then cured over a 10-mm-thick glass slide for 20 s. The shear bond strength was determined using a universal testing machine at a crosshead speed of 1.0 mm/min by placing a knife-edged blade immediately adjacent and parallel to the adhesive interface between the repair material (flowable composite) and the bis-acryl resin provisional material. The mean shear bond strengths ranged from 8.98 to 17.14 MPa. The highest mean shear bond strength corresponded to the bonding group (17.14 MPa), whereas the air-particle abrasion group exhibited the lowest mean shear bond strength (8.98 MPa). Surface treatment of bis-acryl resins with bonding appears to be a promising approach for improving repair bond strength, and the bonding group exhibited the highest levels of bond strength.     

Interfacial integrity of low-shrinkage composite restorations related to the filling technique and consistency

Purpose: To evaluate the influence of filling techniques and consistency of low-shrinkage composites on the bond strength and internal gap formation in Class I bonded restorations. Two low-shrinkage restorative systems (N’Durance/Septodont and Filtek Silorane/3M ESPE) were used to restore Class I preparations. Bulk increment, two oblique increments or two horizontal increments were performed and Filtek Z350XT was used as a control. Each increment was photoactivated for 40?s and the restored teeth were then stored for 24?h at 37?°C before being longitudinally sectioned and the internal margins of the restorations dyed with 1% acid-red propylene glycol solution for 20?s. The specimens were water rinsed and digital images were recorded for the internal gap formation (%) analysis. Stick-shaped specimens were also tested in tension to evaluate the bond strength. Comparative consistency of unset composites was also performed. N’Durance exhibited the highest incidence of internal gaps amongst all the filling techniques. Filtek Silorane showed no significant difference of internal gap formation in comparison with Filtek Z350XT, regardless of the filling technique. Filtek Z350XT exhibited the highest bond strength and N’Durance the lowest when horizontally applied; bond strength of Filtek Silorane was not influenced by the filling technique. Both Filtek Z350XT and N’Durance presented lower consistency. Low-shrinkage composites seem to present equivalent or inferior bond strength and internal gap formation when compared to the methacrylate composite. The quality of the Class I preparation is dependent on the material and filling techniques.     

Effect of different dentin adhesives and application modes on sealing ability of amalgam restorations

Purpose: The aim of the study was to evaluate the sealing ability of bonded amalgam restorations using different adhesive materials with different adhesive application methods including amalgam bonding application. Materials and methods: The prepared Class-V cavities were randomly assigned to four application groups of four tested dual-curing dentin adhesives (Scotchbond Multi-Purpose Plus, XP Bond, Xeno IV and Clearfil Liner Bond 2V), dual-curing resin-based cement (Panavia F2.0) and a control group (unlined amalgam). Group 1 adhesives were applied according to the instructions for direct light-curing, Group 2 chemical-curing mode was applied according to the manufacturer’s amalgam bonding instructions. Group 3 adhesives were first applied in light-curing mode, and then amalgam bonding adhesive was applied. Group 4 adhesives were first applied in chemical-curing mode, followed immediately by light-curing mode. After that, amalgam adhesive parts were applied; then, the amalgam was condensed and carved. After storage for 24 h in distilled water at 37 °C, restorations were finished and polished. The teeth were then thermocycled (500 cycles between 5 and 55 °C), and the specimens were examined for microleakage using methylene blue as a marker. Results: Compared to the control group, the adhesive application modes significantly reduced microleakage for both dentin and enamel margins (p < 0.05). In dentin margins of the adhesives tested, Group 4 showed the lowest leakage score. On the enamel margins for Scotchbond Multi-Purpose Plus and XP Bond, Group 1 showed the highest microleakage (p < 0.05). Conclusion: According to marginal sealing ability and ease of application, Group 2 was recommended for the etch and rinse systems, and Group 4 was also recommended for the self-etch systems under amalgam restorations.     

Load-bearing capacity and failure types of premolars restored with sonic activated bulk-fill-, nano-hybrid and silorane-based resin restorative materials

This study evaluated the load-bearing capacity of premolars restored with three types of resin composite materials in mesio-occluso-distal (MOD) cavities. Extracted human premolars (N = 30, n = 10 per group) were randomly divided into three groups; MOD cavities were prepared and restored with one of the following resin materials: Group BFC: Bulk-fill composite (SonicFill, Kerr Corporation), Group NC: Nanohybrid resin composite (Filtek Z550, 3M ESPE), Group SC: Silorane-based composite (Filtek Silorane, 3M ESPE). For NC Clearfil SE Bond (Kuraray, Japan) and for SC, Silorane adhesive resin (Filtek Silorane System Adhesive, 3M ESPE) were used. The cavities in NC and SC groups were restored incrementally, while those in BFC groups were restored in bulk. After water storage (24 h, 37 °C), each tooth was subjected to compressive loading with a stainless steel ball (diameter: 4 mm) perpendicular to the occlusal surface (1 mm/min). Failure types were categorized according to being repairable or irrepairable. Data were statistically analysed using Kruskal-Wallis test (α = 0.05). Two-parameter Weibull distribution values including the Weibull modulus, scale (m) and shape (0) values were calculated. Fracture resistance of premolars restored with BFC (829.84), NC (701.35) and SC (807.73) did not show significant difference (p = 0.72). Weibull distribution presented lower shape (0) for SC (m = 2.77) and NC (m = 3.09) compared to BFC (m = 5.01). The incidence of repairable failures was more common in BFC (80%) compared to NC (60%) and SC (50%). Adhesive failures were more often observed in NC (80%) and SC (70%) groups.     

Structural changes of starch/polyvinyl alcohol biocomposite films reinforced with microcrystalline cellulose due to biodegradation in simulated aerobic compost environment

Starch/Polyvinyl alcohol (PVA) based biocomposite films reinforced with micro crystalline cellulose (MCC) (10 wt %) particles were prepared by solution casting method, incorporating glycerol as plasticizer. These biocomposite films were subjected to biodegradation at ambient temperature in a simulated aerobic compost pit. The extent of biodegradation of these films was studied in terms of weight loss. The corresponding changes in the structure of the films were observed using scanning electron microscopy, X‐Ray diffraction study, and differential scanning calorimetry. The melting point of PVA component of the biocomposite film shifted from 204 to 223°C with increase in biodegradation time and a remarkable difference was observed in their melt crystallization behavior. The unreinforced films also showed a similar trend, but the increase in the crystallinity of PVA was more pronounced in MCC reinforced films than that observed in the unreinforced ones. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Effect of patch hybridization on the tensile behavior of patch repaired glass/epoxy composite laminates using acoustic emission monitoring

This paper investigates the tensile response of damaged glass/epoxy composite laminates repaired using hybrid external patches. Hybrid external patches based on glass and Kevlar woven fabrics bonded on both faces of the damaged parent laminate were considered. Five different kinds of plain weave woven fabrics with a different ratio between glass and Kevlar fibers (100/0, 75/25, 50/50, 25/75 and 0/100) were used as the external patches. The intention of using these hybrid patches was to combine the excellent tensile stiffness of Kevlar fiber with the superior resin adhesion property of glass fiber. The virgin and damaged specimens were taken as the reference specimens for comparison of residual mechanical properties and damage mechanisms. Damage evolution and the failure progression of the repaired glass/epoxy specimens were monitored using real-time Acoustic Emission (AE) monitoring technique. The Acoustic Emission (AE) results depict different damage profiles and link them with mechanical test results to reveal the load to a change in failure mechanisms during mechanical loading concerning the influence of each hybrid patches on the performance of repaired glass/epoxy specimens. Good correlation of the acoustic emission results with the photographic images of fractured specimens was obtained. Specimens repaired with the equal volume fraction of glass and Kevlar fibers in the external patches presented the most favorable residual tensile response by effectively releasing the stress concentration in the damaged area.     

Efficacy of different surface treatments and universal adhesives on the microtensile bond strength of bulk-fill composite repair

Abstract

The purpose of this in vitro study was to evaluate the influence of different surface treatments and aging on the microtensile bond strength (μTBS) of bulk-fill composite resins. Bulk-fill composites (Filtek One; 3M ESPE) randomly received five different surface treatments: (1) no treatment, control, (2) 37% phosphoric acid etching (PA), (3) 9% hydrofluoric acid etching (HF), (4) air-borne particle abrasion with 50-μm alumina particles (Al₂O₃), (5) tribochemical silica coating (CoJet). Following, the specimens were divided into three subgroups according to universal adhesive applied: Clearfil Universal Bond (CU; Kuraray), Prime&Bond Universal (PBU; Dentsply Sirona), or Single Bond Universal (SBU; 3M ESPE). A nanofill composite (Filtek Ultimate; 3M ESPE) was employed as a repair. Bonded specimens were stored in water for 24?h at 37?°C or thermal aged, then subjected to the μTBS test. Additionally, specimens were analyzed with a contact profilometer and were evaluated with scanning electron microscopy. Control and PA treatments were showed the lowest µTBS (p?<?0.05), and there was no significant difference between these two groups (p?>?0.05). Al₂O₃ and CoJet treatments generally exhibited a similar influence on µTBS values. In addition, a correlation was found between surface roughness and bond strength (r?=?0.831). CoJet resulted in significantly higher repair µTBS values when compared to the other surface treatments. In addition, the use of silane-containing universal adhesive was increased the cohesive failure rate and maintained the repair µTBS values after thermocycling.     

Hygrothermal ageing effect of ADEKIT A140 adhesive on the J-integral of a plate repaired by composite patch

The effect of an hygrothermal ageing on the mechanical behavior of the bulk adhesive ‘Adekit A140 epoxy’ was investigated. The bulk test specimens of the adhesive were immersed in distilled water at various temperatures (20, 40 and 60 °C). Under these conditions, the tensile properties were determined and used in a numerical study about the behavior of bonded assemblies allowing to calculate the J-Integral. The obtained results illustrate the variation of the mechanical behavior of bulk adhesive depending on the immersion time and environmental temperature. The presence of water in the adhesive decreases the tensile strength and the elastic modulus but also increases the ductility of material. These changes in mechanical properties are more important when the percentage of water absorbed increases. The temperature increases the amount of absorbed water in the adhesive, consequently increases the degradation kinetics with the immersion time and directly affect the load transfer rate of the damaged area to the composite patch and therefore the value of the integral J.     

J-116结构胶粘剂与QY8911树脂匹配性研究

本文利用漫反射傅立叶交换红外光谱法、扫描电镜法和溶度参数法研究了J－116结构胶粘剂和QY8911树脂之间的相容性．     

Effect of filler–fiber interactions on compressive strength of fly ash and short‐fiber epoxy composites

Compressive properties of epoxy composites reinforced with fly ash and fibers, which have differing aspect ratios, are studied. Retention of strength and modulus are observed for a greater range of fiber volume fractions following fly ash introduction into the system. A slight decrease in density was also observed when fly ash content was higher, making these composites with materials of differing aspect ratio bearing reinforcement systems suitable in weight specific applications. The investigations showed that strength decrease is larger in fiber‐bearing samples compared with only ash‐bearing samples. This decrease was ascribed to the tendency of fibers to bunch. When the ash filler was introduced, this tendency of fibers to cluster appears to be reduced, resulting in increased strength and modulus. Further attempts are made to analyze these interactions of fibers and fillers through observations made on the surfaces of failed samples by scanning electron microscopy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 836–841, 2003     

Immediate and delayed repair bond strength of a new ormocer resin restorative material as a function of mechanical and chemical surface conditioning methods

This study evaluated the μ-shear repair bond strength (μSBS) of a new ormocer restorative material as a function of repair time and repair protocol. Ormocer disks (N = 140) (Admira Fusion, Voco) were prepared and divided into 14 groups: Factor 1: Bonding protocol (No Conditioning, Admira Bond, Futurabond M+, Silane/Admira bond, Silane/Futurabond M+, Ceramic repair system, Silane/Cimara bond) and Factor 2: Repair procedure time (immediate versus delayed). Each disk received two ormocer micro-cylinders. Half of the disks were repaired immediately (24 h) and the other half after six-month water storage. Shear test was run at cross-head speed of 0.5 mm/min. Debonded specimens were evaluated for failure mode and SEM analysis was performed. Data were analyzed using two-way ANOVA and Tukey’s tests (p < 0.05). Both the repair time and the surface conditioning method showed a significant effect on the repair μSBS (MPa) of the ormocer material (p = 0.000). When immediate repair strengths were considered, all repair protocols tested reached the mean bond achieved based on oxygen-inhibited layer (10.8 ± 2.4 MPa), except. Futurabond M+(13.9 ± 3.4) and Silane/Cimara adhesives (16.3 ± 2.9) showed significantly higher μSBS (p = 0.001 and p = 0.000, respectively). For the delayed repair, non-conditioned (5 ± 1.7), showed significantly lower values compared to those of the other protocols (p < 0.05). Failure modes were predominantly adhesive type (immediate:95% and delayed:90%). No cohesive failures were observed either in the substrate or in the repair material.     

Interrelation of Scanning Electron Micrographs with Flexural Behavior of Ferrite and Nano-Barium Titanate Reinforced Poly-Ether-Ether-Ketone (PEEK) Composites

ABSTRACT

The flexural behavior of ferrite filled poly-ether-ether-ketone (PEEK) composites, with and without reinforcement of nano-barium titanate, was studied and was corroborated through scanning electron microscopy (SEM). In this study, ferrite filled PEEK, and ferrite and nano-barium titanate reinforced PEEK composites were prepared. Ferrite filled PEEK composites showed reduction in flexural strength and increase in flexural modulus with the increase in ferrite content, whereas, with the reinforcement of nano-barium titanate, flexural strength increased and flexural modulus decreased at similar ferrite content. The SEM micrographs corroborated well with flexural behavior, as ferrite particles and smooth topographic surfaces of brittle fracture were evident in the samples having higher ferrite content in ferrite filled PEEK composites, whereas, typical yield pattern of crust and trough on fractured topographic surfaces of ferrite and nano-barium titanate, reinforced PEEK composites, was visible.