Affect Bond Strength Research Articles

Effect of Post Sizes and Citric Acid Treatment on the Bond Strength of Fiber Posts Using Self-Etch Resin Cement in Calcium Silicate–Based Sealer Treated Teeth

Abstract Objectives This study evaluated the effects of different post sizes and citric acid (CA) treatment on the bond strength of fiber posts cemented with self-etch resin cement in teeth obturated with calcium silicate–based sealer. Materials and Methods Seventy mandibular premolars were collected and randomly distributed to either a control group (no sealer) or experimental groups obturated with calcium silicate–based sealer (iRoot SP). The experimental groups were classified by post sizes—1.25 mm (no. 1), 1.375 mm (no. 2), and 1.50 mm (no. 3)—and the irrigants used (distilled water [DW] or CA). Prefabricated fiber posts were fixed using NX3 self-etch resin cement. Push-out bond strength was tested in the coronal and middle sections of the roots. Statistical Analysis The data were analyzed using a one-way analysis of variance (ANOVA), followed by a post hoc Duncan test. Results In the coronal section, post size no. 1 with DW showed significantly lower bond strength compared to the other experimental groups (p < 0.05). In the middle section, the larger post sizes (nos. 2 and 3) with CA treatment resulted in a significant increase in bond strength compared to the control group (p < 0.05). Conclusions iRoot SP negatively affected bond strength in the middle section of the canal. However, using larger post sizes (nos. 2 and 3) with CA treatment improved bond strength in the middle section.

Characterization of 3D printed composite for final dental restorations.

This study evaluated the mechanical, optical, microstructural, surface, and adhesive behavior of a 3D printing resin comparing it with a machinable resin composite. Specimens of different sizes and shapes were either printed (Vitality, Smart Dent) or machinable (Grandio Blocs, Voco GmbH) resin composites with similar composition were prepared. Surface and mechanical characterization were performed with Knoop hardness, flexural strength (three-point-bending), and elastic modulus tests. The wear of the tested materials was evaluated against steatite antagonists. The optical properties stability (color change, ΔE00, and translucency, TP00) were observed after staining in red wine. In addition, the bond strength of the resin composites to two resin cement protocols were investigated with microshear bond strength tests at baseline and after thermocycling. Scanning electron microscope (SEM) coupled with Energy-Dispersive X-ray Spectroscopy (EDS) was used for microstructural and chemical characterization. Statistical analyses were performed with t- and ANOVA tests. Hardness values (132.76 (16.32) KH- Machinable and 35.87 (2.78) KH - Printed), flexural strength (172.17 (26.99) MPa - Machinable and 88.69 (8.39) MPa - Printed), color and translucency change (1.86 (0.31)/0.06 - Machinable and 3.73 (0.36)/9,16- Printed), and wear depth (24.97mm (3.60)- Machinable and 7.16mm (2.84) - Printed) were statistically different. Average Regarding bond strength, mean values (MPa) for non-aged and aged groups were respectively 21.76 (6.64) / 31.9 (12.66) for Bifix cement (Voco GmbH, Cuxhaven, Germany) and 26.75 (5.14) / 24.36 (6.85) for Variolink cement (Ivoclar Vivadent, Schaan, Liechtenstein) in Printed and 17.79 (3.89) / 9.01 (3.36) ) for Bifix cement and 22.09 (6.55) / 11.01 (3.77) for Variolink cement in Machinable materials. The material and aging factors did affect bond strength but the cement factor did not (p = 0.202). No statistical differences were observed for mean roughness (Ra) between materials. The better dispersion and larger size of the inorganic particles in the Machinable resin were contrasted with the clustered smaller particles of printed resin, under SEM. The mechanical properties and color stability of the machinable resin were superior to those of the printed resin, probably due to the greater amount and dispersion of inorganic particles in the Mach resin, but bond strength after aging was stronger and more stable in the printed resin. 3D-printed resin composites with similar compositions to machinable resin composites do not necessarily exhibit the same properties, which can impact clinical performance. Understanding these differences can assist manufacturers in improving their materials and help clinicians distinguish between materials appropriate for provisional and final restorations.

Does the Application of Anti-Erosive Substances on Eroded Dentin Affect Bond Strength? A Systematic Review

This systematic review evaluated whether using anti-erosive agents as a pretreatment of eroded dentin before bonding with resin composite affects the bond strength. A search was conducted by two reviewers in the PubMed, Embase, Scopus, Web of Science, and Science Direct databases in January 2023. Articles that employed artificially eroded human dentin and performed treatment prior to adhesion with anti-erosive substances were eligible. A validated tool with 12 items regarding in vitro studies was used to assess the risk of bias in the selected articles, obtaining a final score for each study. Four in vitro studies were included in this systematic review. Most studies used the microtensile bond strength test; most failures were adhesive or mixed. No tested substance negatively affected the bond strength to eroded dentin. Sodium fluoride (NaF), tin-containing fluoride (Sn/F) and silver diamine fluoride (Ag(NH₃)₂F) have been proven not to interfere with or improve bond strength to eroded dentin.

Investigation of interfacial bond strength of circular CFST columns based on ordinary and inorganic polymers through advanced machine learning methods

Concrete-filled steel tube (CFST) is a combination of materials, in which the interfacial bond-slip behavior is the prerequisite to reflect the synergistic loading of external steel tube and core concrete. The inorganic polymer concrete within the concrete-filled steel tube (IPCFST) compensates for the drying shrinkage of the concrete and enhances the adhesion at the interface between the steel tube and the concrete. However, the current code is too simple for the bond strength of CFSTs, and the existing theoretical calculation methods are not universally applicable. This paper aims to develop a practical artificial neural network tool for predicting the interfacial bond strength of ordinary CFSTs and IPCFSTs. An efficient prediction model for the bond strength of CFST interfaces was developed using a radial basis function network (RBFNN), with concrete strength, steel tube size, bond length and other factors as the main parameters. Bond performance test data was collected for a sample database of 322 circular CFST columns, including 56 ordinary CFSTs and 263 IPCFSTs. The results show that the Artificial Neural Network (ANN) algorithm can effectively address the bond strength problem of CFST structures and improve the accuracy and density of prediction in the comparative analyses with the measured values and the results of the semi-theoretical formulations. Based on the prediction results of ANN model, a sensitivity analysis of the parameters using Garson's algorithm shows that the diameter-to-thickness ratio and concrete strength significantly affect bond strength for both ordinary CFSTs and IPCFSTs. This study provides a more reliable prediction method and technical support for the engineering design of CFST structures.

Effects of the application protocol and bonding strategy of the universal adhesive on dentin previously impregnated with bioceramic sealer

PurposeTo evaluate the effects of the application of universal adhesive with manual brush (MB) or rotary brush (RB), in the etch-and-rinse (ER) or self-etching (SE) strategy, on the bond strength, adhesive layer thickness, and adhesive failure pattern to dentin impregnated with bioceramic sealer, at 24 h and 1 year. Materials and methodsEighty-eight bovine incisor crowns were impregnated with bioceramic sealer was kept for 15 min and cleaned with cotton soaked in distilled water. They were then divided into four groups (n = 22): ER-MB, ER-RB, SE-MB, SE-RB. Subsequently, the specimens were restored with Filtek Z-250 resin. The adhesive layer thickness was individually analyzed using laser confocal microscope. Bond strength was assessed through microtensile testing, and the failure pattern was examined using a stereomicroscope. Data were analyzed by one-way ANOVA/Tukey's tests (α = 0.05). ResultsThe adhesive layer thickness provided by ER-MB and SE-MB was greater than that provided by ER-RB and SE-RB (P < 0.05). ER-MB showed the lowest bond strength at 24 h (P < 0.05). At 1 year, SE-MB and SE-RB exhibited the highest bond strength values (P < 0.05). ER-MB demonstrated a higher incidence of adhesive failure at 24 h. At 1 year, SE-RB and SE-MB showed a higher incidence of mixed failure. ConclusionThe use of Scotchbond Universal® adhesive in the etch-and-rinse strategy applied with a MB negatively affects bond strength at 24 h, worsening after 1 year of control, regardless of the application protocol.

Effect of radiotherapy, immediate dentin sealing and irrigation simulating single- or two-visits endodontic treatment on the bond strength to pulp chamber dentin: an in vitro study.

This study aimed to evaluate the influence of radiotherapy and different endodontic treatment protocols on the bond strength to pulp chamber dentin. Eighty mandibular molars were randomly divided into two groups (n = 40): non-irradiated and irradiated (60Gy). The pulp chambers were sectioned, and each group was subdivided (n = 8), according to the endodontic treatment protocol: no treatment (Control); Single-visit; Two-visits; Immediate dentin sealing (IDS) + single-visit; and IDS + two-visits. Each endodontic treatment visit was simulated through irrigation with 2.5% NaOCl, 17% EDTA and distilled water. IDS was performed by actively applying two coats of a universal adhesive to the lateral walls of the pulp chamber. After, the pulp chambers were restored with resin composite and four sticks were obtained for microtensile test. In addition, the dentin of the pulp chamber roof was assessed for surface roughness, chemical composition, and topography after each treatment protocol. Two-way ANOVA, Tukey's post hoc, Mann-Whitney, Kruskal-Wallis and Dunn's post hoc were performed (α = 5%). The treatment protocol affected bond strength (p < 0.05), while the irradiation did not (p > 0.05). The control group presented the highest values (p < 0.05). The single-visit group demonstrated better performance compared to the other groups (p < 0.05), which did not differ from each other (p > 0.05) The use of IDS changed the surface roughness (p < 0.05), chemical composition (p < 0.05) and topography of the dentin. In conclusion, the treatment protocol influenced dentin adhesion, while irradiation did not.

Bond Strength of Milled and Printed Zirconia to 10-Methacryloyloxydecyl Dihydrogen Phosphate (10-MDP) Resin Cement as a Function of Ceramic Conditioning, Disinfection and Ageing.

This study aimed to assess the suitability of printed zirconia (ZrO2) for adhesive cementation compared to milled ZrO2. Surface conditioning protocols and disinfection effects on bond strength were also investigated. ZrO2 discs (n = 14/group) underwent either alumina (Al2O3) airborne particle abrasion (APA; 50 µm, 0.10 MPa) or tribochemical silicatisation (TSC; 110 µm Al2O3, 0.28 MPa and 110 µm silica-modified Al2O3, 0.28 MPa), followed by disinfection (1 min immersion in 70% isopropanol, 15 s water spray, 10 s drying with oil-free air) for half of the discs. A resin cement containing 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) was used for bonding (for TSC specimens after application of a primer containing silane and 10-MDP). Tensile bond strength was measured after storage for 24 h at 100% relative humidity or after 30 days in water, including 7500 thermocycles. Surface conditioning significantly affected bond strength, with higher values for TSC specimens. Ageing and the interaction of conditioning, disinfection and ageing also impacted bond strength. Disinfection combined with APA mitigated ageing-related bond strength decrease but exacerbated it for TSC specimens. Despite these effects, high bond strengths were maintained even after disinfection and ageing. Adhesive cementation of printed ZrO2 restorations exhibited comparable bond strengths to milled ZrO2, highlighting its feasibility in clinical applications.

Does the universal adhesive's film thickness affect dentin-bonding effectiveness?

To investigate the influence of adhesive resin application modalities on the film thickness of the adhesive resin and the effectiveness of a two-step universal adhesive (UA) bonded in self-etch (SE) bonding mode to high C-factor class-I cavity-bottom dentin. After application of the primer of G2-Bond Universal (G2B, GC), the adhesive resin was applied into standard class-I cavities (human molars) following four application modalities: (1) one layer, strongly air-blown; (2) one layer, gently air-blown; (3) two layers, each gently air-blown; (4) one layer, not air-blown. After being restored with composite, each tooth was sectioned to obtain one micro-specimen (n = 10), of which the adhesive resin film thickness was measured using optical microscopy. The micro-tensile bond strength (μTBS) was tested immediately or upon 100,000 thermocycles. Statistical analyses involved Kruskal-Wallis and Mann-Whitney U testing (p < 0.05). G2B's μTBS was significantly affected by the adhesive resin application modality and aging. Gently air-blowing the adhesive resin resulted in significantly higher immediate μTBS than strong air-blowing or no air-blowing. No significant difference in μTBS was found between single or double gently air-blown adhesive resin applications. The adhesive resin film thickness significantly varied with the application modalities. A too thin or too thick adhesive resin film thickness adversely affected bond strength of the two-step UA applied in SE mode and high C-factor condition. The adhesive resin layer thickness can affect the bonding performance of two-step UAs in high C-factor cavities. Dental clinicians remain advised to avoid improper air-blowing of UAs and strictly follow the application instructions.

Influence of Ozonated Water and Photodynamic Therapy on the Bond Strength of Anatomical Fiberglass Posts to Root Dentin. An In Vitro Study

ABSTRACT This study evaluates, in vitro, the effects of ozonated water as auxiliary endodontic irrigating and photodynamic therapy on the bond strength of fiberglass posts to root dentin. Sixty bovine incisors were prepared and divided into six groups (n=10):Oxidation only G1 Distilled water G2 5.25% NaOCl G3 10–15mg/L O3. Ox+PDT G4 DW+PDT G5 NaOCl+PDT G6 O3+PDT. Anatomical fiberglass posts were cemented and the roots were sectioned and submitted to the push-out test. Bond strength values were analyzed with two-way ANOVA and Tukey 5%. Failure patterns were analyzed. Sodium hypochlorite and ozonated water without photodynamic therapy showed the highest bond strength, and sodium hypochlorite with photodynamic therapy had the lowest bond strength. The O3+PDT association showed intermediate results. Considering that the main purpose of the O3 is disinfection, it was noted that ozonated water did not interfere on the bond strength of fiberglass posts to root dentin. Photodynamic therapy affected bond strength, mainly when associated with sodium hypochlorite. The ozonated water increases the PDT bond strength results.

Advanced statistical analyses to reduce inconsistencies in bond strength data focused on donor factors: A six-factor analysis using linear mixed and nonlinear regression models.

This study aimed to investigate the effects of the age and sex of tooth donors on dentin bond strength. A total of 38 extracted teeth (12 male and 26 female donors; age range: 17-82 years) were used in this study. In addition to donor age and sex, four other microtensile bond strength (μTBS) test specimen factors were evaluated: dentin position, bonding area, presence of voids at the interface, and computed tomography (CT) values of dentin. The μTBS was measured immediately (24 h) and 6 months after storage in water. After the μTBS testing, linear mixed and nonlinear regression models were used to analyze the effects of these factors on the μTBS data. The results from the linear mixed model revealed that the bonding area (P = 0.02), presence of voids at the interface (P = 0.04), and storage time (P < 0.001) significantly affected bond strength. In contrast, no correlation was observed between the μ TBS and dentin position (P = 0.08) or sex (P = 0.07). The results of the nonlinear regression model with robust variance-covariance estimators revealed that age significantly affected bond strength (P < 0.001). In addition, a significant positive correlation was found between μTBS and age (P < 0.001), with nonlinearity (P = 0.002). However, no correlation was observed between the μTBS and CT values (P = 0.69) without nonlinearity (P = 0.39). These findings suggest that bond strength increases with age until 60 years but not afterward.

Longitudinal bond strength of a universal adhesive and chemical dentin characterization under different acid etching protocols.

This study aimed to analyze the longitudinal bond strength of a universal adhesive and chemically characterize the dentin substrate under different acid etching protocols. Dentin samples were etched with polyacrylic acid 25% (PAA) for 10 seconds (n=3) and phosphoric acid 32% (PA) for 15 seconds (n=3) and analyzed by Fourier transform infrared spectroscopy - attenuated total reflectance (FTIR-ATR) before and after treatment. For collagen degradation, samples (n=12) were divided into 3 groups: PAA, PA, and Deionized water (control), and analyzed by the quantity of solubilized type I collagen C-terminal cross-linked telopeptides and solubilized C-terminal peptide in relation to total protein concentration (ICTPtp and CTXtp) and by their ultimate tensile strength (UTS). For the adhesive interface analysis, dentin samples (n=72) were divided into 3 groups: PAA, PA, and Self-etch (SE), and subdivided into 2 groups: 24 h (baseline) and 1 year. The following tests were performed: microtensile bond strength (μTBS) (n=48), scanning electron microscopy (SEM) (n=12), and nanoleakage (n=12). The FTIR of PAA showed lower reduction of the peaks in the phosphate group when compared to PA. For ICTPtp, PA showed a significantly higher value. For CTXtp, PA and PAA groups failed to statically differ from each other. UTS was significantly lower for PA. For μTBS, storage time significantly affected bond strength. The results were unaffected by the etching protocol. For SEM, after 1 year, PA had little evidence of degradation in the upper third of the adhesive interface in comparison to the other groups. Nanoleakage showed no considerable silver impregnation after 1 year in the SE group. The use of PAA prior to a universal adhesive (when compared to PA) represents a less aggressive type of etching to dentin. However, self-etching still seems to be the best option for universal adhesive systems that have functional monomers in their composition.

Delamination Behavior Characterization during Bond Strength Measurement

Direct bonding is a key enabler for future node 3D semiconductor devices [1]. It is crucial to have sufficient bonding strength to withstand thinning and subsequent processes. However, there is no standardized method for bonding strength measurement. The most frequently used bonding strength measurement technique is the double cantilever beam (DCB) method. However, it is known that delamination length propagates with time by water stress corrosion. Nevertheless, the reported bonding strength is not considered these phenomena. Therefore, interfacial reactions occurred by blade insertion have been deeply investigated in this study. We unveiled the influence of annealing and plasma conditions on the bonding strength measurement using the DCB method in a controlled environment. In addition, we discuss the behavior of delamination during blade insertion.Our DCB system is compatible with 300 mm wafers and the insertion of the blade is fully controlled by actuator. The blade is inserted at the bonding interface as shown in Fig.a, and the delamination length is measured from a captured IR image.Fig.b shows the results of bonding strength measurements on 300 mm bonded wafers with different annealing conditions. It can be seen that the bonding strength increases with the annealing temperature. When the annealing temperature is lower than 150℃, the delamination length is propagated by the time even when the measurement is performed in anhydrous environments. Therefore, the calculated results of bonding energy decrease due to this phenomenon.Fig.c shows the bonding energy reduction rate for each annealing temperature with time. These values are calculated based on the value immediately after insertion and after 180 seconds. The results show that water stress corrosion significantly affects the delamination length when annealed at 150℃, however, the samples annealed above 250℃ show almost no propagation of delamination length with time and the values are almost saturated.In this paper, we present the experimental results on the effects of annealing temperatures on bond strength as well as the propagation of delamination length caused by water stress corrosion. Additionally, we will discuss other factors that can affect bond strength measurements during the presentation. Figure 1

Optimizing Dental Bond Strength: Insights from Comprehensive Literature Review and Future Implications for Clinical Practice.

This review examines the modifying factors affecting bond strength in various bonding scenarios, particularly their relevance to the longevity of dental restorations. Understanding these factors is crucial for improving clinical outcomes in dentistry. Data were gathered from the PubMed database, ResearchGate, and Google Scholar resources, covering studies from 1992 to 2022. The findings suggest that for dentin-resin bonds, minimizing smear layers and utilizing MMP inhibitors to prevent hybrid layer degradation are essential. In the case of resin-resin bonds, reversing blood contamination is possible, but preventing saliva contamination is more challenging, underscoring its critical importance during clinical procedures. Additionally, while pretreatment on ceramics has minimal impact on bond strength, the influence of specific colorings should be carefully considered in treatment planning. This comprehensive review highlights that although established practices recognize significant bond strength factors, ongoing research provides valuable insights to enhance the clinical experience for patients. Once confirmed through rigorous experimentation, these emerging findings should be swiftly integrated into dental practice to improve patient outcomes.

Effects of Hydrofluoric Acid Concentrations, Commercial Brands, and Adhesive Application on the Bond Strength of a Resin Luting Agent to Lithium Disilicate Glass Ceramic.

To evaluate the surface topography/roughness and bond strength of a resin luting agent to a lithium disilicate glass ceramic after etching with different concentrations of hydrofluoric acid (HF) and commercial brands. For bond strength evaluation, 260 lithium disilicate glass ceramic (EMX) discs were randomly distributed into 13 groups based on concentrations of HF and commercial brands (n=20): 5% and 10%, Lysanda (LY5 and LY10); 5% and 10%, Maquira (MA5 and MA10); 5% and 10%, FGM (FG5 and FG10); 4.8%, Ivoclar Vivadent (IV5); 5% and 10%, PHS do Brasil (PH5 and PH10); 5% and 10%, BM4 (BM5 and BM10); 9%, Ultradent Inc (UL10); and Dentsply (DE10). A further random distribution (n=10) was made based on the application (+) or absence (-) of an adhesive layer. Resin luting agent cylinders (1 mm in diameter) were added on EMX surfaces, light-cured, and stored for 24 hours in deionized water at 37°C. On a universal testing machine (DL 500, EMIC), specimens were submitted to a microshear bond strength test at a crosshead speed of 1 mm/min until failure. A representative etched EMX disc from each group underwent surface topography analysis using field-emission scanning electron microscopy (n=1), and five (n=5) etched EMX discs from each group were tested for surface roughness. Data were statistically analyzed using analysis of variance and Tukey test (α=0.05). A less conditioned and smoother surface was observed for 5% HF compared to 10%. Additionally, commercial brands of HF were shown to affect bond strength. When the adhesive layer was not used (-), a 10% concentration promoted higher bond strengths to EMX. However, when adhesive was applied (+), the concentrations of HF and commercial brands had no effect on bond strength results. A 10% concentration of HF results in higher bond strength than a 5% concentration. If an adhesive layer is applied, neither this distinction nor the influence of commercial brands is observed.

Bonding performance of different types of expired and unexpired composite resin cements

Aim: The aim of this study was to compare the bond strength of three expired and unexpired composite resin cements used between tooth and ceramic surfaces. Methodology: In this study, the dentin surfaces of 60 non-carious human teeth and ceramic specimens were bonded with three different resin cements. The resin cements used to bond the teeth and ceramic blocks were divided into two subgroups by expiration date (Group 1a. Variolink II-unexpired, 1b. Variolink II-expired 12 months prior. Group 2a. RelyX Unicem-unexpired, 2b. RelyX Unicem-expired 12 months prior. Group 3a. Panavia F 2.0-unexpired, 3b. Panavia F 2.0-expired 12 months prior). The samples were thermally cycled for 3,000 cycles in a temperature range of 5°C–55°C. The shear bonding test was performed using a universal tester. The force required for ceramic debonding was recorded. Surface fracture analysis was performed using a stereomicroscope. Mann–Whitney U test was used to compare the bond strength of resin cements with different expiration dates. P-value &lt; 0.05 was considered statistically significant. Results: The difference in bond strength between the unexpired resin and the resin that had expired 12 months before the analysis was found not to be statistically significant in the Variolink II and Panavia pairs but significant in the RelyX resin cement pair. Conclusion: The self-adhesive resin cements that expired one year earlier showed lower bond strength than their unexpired counterparts; however, the use of expired total-etch and self-etch systems did not significantly affect bond strength. How to cite this article: Karagözoğlu İ, Aksel L. Bonding performance of different types of expired and unexpired composite resin cements. Int Dent Res 2023;13(2):54-59. https://doi.org/10.5577/idr.2023.vol13.no2.2 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Experimental study on structural adhesive properties of aluminum plate and carbon fiber-reinforced polymer heterogeneous materials

Structural adhesive bonding between aluminum and carbon fiber-reinforced polymer (CFRP) is an important part of the vehicle's lightweight design and must ensure high strength and durability during the life of the structural member. The paper presents a precise assessment scheme to accurately and reliably infer the performance of adhesive joints through a short-term experimental test method that focuses on intrinsic and extrinsic factors affecting bond strength. The experimental results show that the surface of CFRP is polished, which is beneficial to improve the bonding quality, and the damage type transitioned from adhesion damage to substrate or cohesion damage. Aluminum alloy electrophoresis and non-electrophoresis have no significant effect on the bonding performance. Secondly, the design of the bonding nodes should be considered to bring them into a state of shear stress and be able to withstand greater loads. Meanwhile, the moderate thickness of the adhesive layer and increased bonding area serve to enhance bond reliability. In addition, various environments can cause various physical and chemical changes within structural adhesives, which can reduce the cohesive strength and durability of adhesives. This experiment is designed to select process parameters and adhesive applications for structural adhesives, which are crucial in predicting and evaluating the performance of newly developed structural adhesives and bonded joints.

Bond strength of ceramic veneered CAD-milled alloy upon prolonged sintering.

Ceramic-sintering affects bond strength and longevity of metal-ceramic. This study investigated the effect of sintering temperatures and times on metal-ceramic bond strength vis-a-vis interfacial fracture toughness. One hundred eighty rectangular-shaped (25 × 8 × 1mm) casting (Auriloy® (CA)) and CAD-milling (Ceramill Sintron® (MA)) alloys were prepared and randomly veneered with ceramic at normal (930°C; (TN)), increased (940°C; (TI)), and extremely increased (950°C; (TE)) sintering temperatures and normal (1min; (HN)), increased (2min; (HI)), and extremely increased (3min; (HE)) sintering time (n = 10/group). Pre-cracked was subjected to four loading-unloading cycles at 0.05mm/min speed to determine interfacial fracture toughness from strain energy release rate (G). Microstructures were examined with a scanning electron microscope (SEM), energy-dispersive X-ray (EDX), and atomic force microscopy (AFM). ANOVA and Tukey comparisons were determined for significant differences (α = 0.05). Significant differences in G due to the effect of alloy, sintering temperature, and time (p < 0.05) were indicated. MA revealed higher G than CA. Raising temperatures enabled increasing G for CA, not for MA. Extended sintering permitted increasing G for both alloys. Rougher surface of MA than CA was observed. Interfacial ion exchange was differently indicated between CA and MA. Bond strength was influenced by alloy, sintering temperature, and time. Ceramic has better adhesion to MA than CA. Enhancing bond for CA was succeeded through increasing sintering temperature and time, whereas through extended sintering for MA. MA offers stronger bond than CA. Enhancing bond is suggested by extended sintering. Raising temperature can enhance bond for CA, not for MA.

A Comprehensive Review on the Factors Affecting Bond Strength in Concrete

The interaction of reinforcement bars with concrete determines the structural behavior and bond performance (bond strength) in reinforced cement concrete. Bond strength and its importance in structural applications based on available standards attracted researchers around the globe to evaluate the bond strength in reinforced cement concrete through various test methods and procedures. In this review article, more than 200 globally published studies were collected, and 170 articles were compiled to discuss the importance of bond strength and the factors that affect bond strength in concrete. The various factors/parameters that affect the bond strength, including concrete type and its properties, the reinforcement bar with its geometry and shape, environmental nature of the specimen with its testing methods and standards, and other miscellaneous factors, were comprehensively analyzed. We present a summary of the findings; a surprising fact was that every factor is responsible for developing bond strength in concrete in one way or another.

In vitro and practical guide for the analysis of bond strength to ceramics

The purpose of this study was to characterize different test designs applied for analysis of the bond strength between ceramic and resin cement. One lithium disilicate (LD, IPS Emax CAD®, Ivoclar) and one zirconia (YZ, Ceramill, Amann-Girrbach) ceramic were used for specimens’ preparation (n = 10) according to the proposed test: Microtensile, Tensile, Microshear, Shear, Micropush-out, Push-out, and Interfacial Fracture Toughness. A resin cement (Multilink Automix dualcure, Ivoclar) was used to bond the ceramic to the substrate (composite resin, Tetric N-Ceram, Ivoclar) selected according to the test design. During preparation and testing of the specimens, the time required, amount of material and level of difficulty were assessed. Bond strength data were analyzed using one-way ANOVA and Tukey test (P < 0.05). The homogeneity and magnitude of the bond strength values were verified by calculating the Weibull modulus. Failure mode was analyzed by stereomicroscope for all tests. Microshear resulted in the highest (LD: 41.00 ± 14.96 MPa; YZ: 48.95 ± 6.64 MPa) and Interfacial Fracture Toughness in the lowest (LD: 3.54 ± 0.94 MPa; YZ: 4.10 ± 1.65 MPa) bond strength values, regardless of the ceramic. The analysis of the mode of failure showed 100% adhesive failure for Microtensile and Micropush-out samples for both, LD and YZ. Interfacial Fracture Toughness samples of LD also presented 100% adhesive failure. Most of the samples presented mixed failure modes, and only Tensile and Push-out tests presented cohesive failure in the resin cement layer. Overall, the test design affected bond strength results. Weibull modulus indicated that a smaller sample size may be adequate for the analysis of bond strength to ceramic materials. Microtensile test was classified as the most difficult test in terms of preparing the specimen and performing the test.

Investigation of factors affecting bond strength of thin epoxy overlay pavements

ABSTRACT This study investigated the factors influencing the bond strength between existing pavement and thin epoxy overlay via laboratory and field tests. Laboratory tests revealed that the highest bond strength occurred at a general temperature and relative humidity of 25 °C and 60%, respectively. The concrete surface profile (CSP) of the specimen was found to have no impact on the bond strength between the latex-modified concrete (LMC) and epoxy binder under favorable conditions. Field testing of well-maintained concrete pavements indicated that neither the existing pavement's pre-treatment process nor its resulting CSP affected the bond strength. However, the bond strength decreased with environmental and vehicle loadings six months after the overlay. A second field test conducted on a deteriorated bridge deck with an LMC pavement revealed that most of the damage occurred at a shallow depth in the existing pavement, demonstrating low bond strength just two days after construction owing to inadequate removal of the deteriorated section. The initially low bond strength increased over time as the epoxy binder permeated the deteriorated area and hardened at greater depths, thus making it necessary to thoroughly remove all deteriorated sections of the existing pavement before constructing a thin epoxy overlay.