Bond Durability Research Articles

Influence of bonding agent application method on the dentin bond durability of a two-step adhesive utilizing a universal-adhesive-derived primer.

This study investigated the effect of the bonding agent application method on the dentin bond durability of a two-step adhesive utilizing a universal-adhesive-derived primer. The bonding durability of a universal adhesive was compared with those of two conventional two-step adhesives by shear bond strength testing after thermal cycling. The primer was applied (with or without phosphoric acid pre-etching), and the specimens were divided into three groups based on the bonding agent application method used as follows: (i) strong air-flow application, (ii) gentle air-flow application, and (iii) gentle air-flow + second bonding application. The shear bond strength was determined after thermal cycling. All the factors (bonding agent application method, adhesive system, and storage condition) significantly influenced the dentin shear bond strength both with and without phosphoric acid pre-etching. The specimens exposed to gentle air-flow showed a higher shear bond strength than did those exposed to strong air-flow and gentle air-flow + second bonding. The bond durability of the tested adhesive systems was influenced by the bonding agent application method, and this trend was material dependent. The G2-Bond Universal exhibited the same or greater dentin bond durability to the other two-step adhesive systems.

Bond behavior of basalt fiber reinforced polymer bars in seawater sea-sand concrete exposed to daily temperature variations

Application of basalt fibre reinforced polymer (BFRP) bar reinforced seawater sea-sand concrete structures in marine and coastal buildings could bring both environmental and economic benefits. As BFRP bar reinforced seawater sea-sand concrete members are likely to be exposed to temperature variations during their service life, the bond durability between BFRP bar and seawater sea-sand concrete should be well understood. This paper investigated the effects of thermal cycling, such as target temperature (i.e. amplitude of variation) and cycling times, bar diameter and concrete strength on the bonding behavior of BFRP bars in seawater sea-sand concrete by pullout test. It is found that target temperature and cycling times lead to a significant reduction of BFRP bar-to-seawater sea-sand concrete bonding, which is mainly attributed by the degradation of BFRP under thermal cycles. Through the method of scanning electron microscopy, microstructure of BFRP is examined and the bond mechanism considering the effect of temperature variations is clarified. Finally, theoretical model is proposed to predict the bond stress-slip relationship of BFRP bars in seawater sea-sand concrete. Accuracy of the predictions is validated by the experimental results.

Application of Sulfinate Agent in Conjunction with HOCl Smear-Layer Deproteinization Improves Dentin Bonding Durability of One-step Self-etch Adhesives.

To evaluate the effect of a sulfinate agent on the bonding durability of one-step self-etch adhesives (1-SEAs) to smear-layer-covered dentin deproteinized with hypochlorous acid (HOCl). Human coronal dentin disks with a standardized smear layer were deproteinized with 100 ppm HOCl solution for 0 s (control), 15 s or 30 s. After rinsing with water for 30 s and air drying, half of the specimens were treated with a sulfinate agent (Scotchbond Universal Dual Cure Activator; SDA) prior to the application of a 1-SEA (Bond Force II [Tokuyama Dental] or Clearfil Universal Bond Quick [Kuraray Noritake]). Microtensile bond strength (µTBS) was measured after 24 h or 10,000 thermal cycles (TC). The data were analyzed by three-way ANOVA with Tukey's post-hoc tests and t-tests at the 0.05 significance level. The 24-h µTBS of both adhesives increased statistically significantly with the HOCl pretreatment for 15 s or 30 s (p < 0.05), but it was not statistically significantly affected by the application of SDA (p > 0.05). However, after TC, the groups treated with the combination of HOCl and SDA maintained their µTBS (p > 0.05), as opposed to untreated dentin and dentin treated with either HOCl or SDA, whose µTBS decreased significantly (p < 0.05). The application of the sulfinate agent did not statistically significantly affect the immediate bond strength of 1-SEAs, and it could not prevent a significant decrease in the bond strength to untreated dentin after thermocycling. However, the sulfinate agent significantly improved the bonding durability of 1-SEAs to HOCl smear-layer deproteinized dentin.

Effect of flavonoids on bond strength of dentin adhesives

The effectiveness of adhesive restorations depends on a durable long-term dentin bond. Due to collagen fibril denaturation, the consistency and durability of bonding to caries-affected dentin can be questioned as compared to sound dentin. Exogenous cross-linking agents have been suggested as a viable method of inhibiting MMP activity and retaining collagen within the dentin-bonded interface. Due to their strong antioxidant capacity, flavonoids are natural cross linkers that play an important role in protecting unprotected collagen fibrils inside the hybrid layer. This study aimed to evaluate the effectiveness of flavonoids incorporated dentin adhesives in improving the bond strength of composite resin. A search was performed in the electronic databases (PUBMED CENTRAL, Medline, Scopus, Lilacs, Science Direct, Google scholar and Hand Search) using search terms alone and in combination by means of PUBMED search builder upto March 2021. Also cross check of reference was done on all potentially eligible articles. Initially 47 articles were identified.2 articles were removed because of duplicates. After title and abstract screening 27 articles were removed.After reading full texts,4 articles were removed and finally 14 articles were included in this review for detailed analysis.

Preliminary Results on Natural Aging of GFRP-Reinforced Masonry Components Exposed to Outdoor Environmental Conditions

Fiber reinforced polymers (FRP) have been widely used for strengthening and repair of masonry structures since the 1990s. Although the short-term performance of such systems has been extensively studied, their durability and long-term behavior are still scarcely known. Therefore, a better understanding of the corresponding degradation mechanisms and durability issues is of major interest, especially in cases of externally bonded systems where the materials are prone to undergo a more severe decay. Different accelerated aging tests have been developed in order to simulate weathering conditions in a shorter time: water immersion, freeze-thaw, hygrothermal cycles, salt crystallization, UV radiation, etc. Nonetheless, accelerated aging data cannot be used to make reliable service life estimations without a clear correlation with real environmental processes. In this study, we present the preliminary results (3/12 years) of a real exposure experimental campaign devoted to analyzing the natural aging of masonry components reinforced with externally bonded glass fibers (GFRP). The aging conditions consist of: (a) direct outdoor exposure, i.e. outdoor hygrothermal variation + sun and rain; (b) indirect outdoor exposure, i.e. outdoor hygrothermal variation + sheltered from sun and rain; (c) laboratory conditions as control group. The specimens consist of solid extruded fired-clay bricks strengthened with unidirectional GFRP sheets following the wet lay-up procedure. The aging effects on bond performance are studied by means of single-lap shear tests. Finally, the effect of brick surface treatment and the application of an external render on bond durability is investigated.

Comprehensive review of the properties of fly ash-based geopolymer with additive of nano-SiO2

Abstract Nano-SiO2 is a non-toxic, tasteless, and pollution-free material with hydroxyl groups that facilitate the adsorption of water on its surface. Nano-SiO2 is characterized by small particle size, high purity, low density, large surface area, and good dispersion properties. In addition, nano-SiO2 has excellent stability, reinforcement, thixotropy, and optical and mechanical properties. The additive of nano-SiO2 can enhance the mechanical properties and microstructure of concrete. Therefore, nano-SiO2 is widely used as an additive in the field of building materials. Geopolymers have excellent mechanical properties, acid–alkali resistance, fire resistance, and high-temperature resistance. In addition, mineral waste and construction waste can be used as raw materials for geopolymers. Therefore, geopolymers have the potential to substitute ordinary Portland cement and have good prospects for application as construction materials. The application of nanomaterials in geopolymer products has shown that nano-SiO2 is effective in increasing the rate of geopolymerization reaction and reducing the setting time of geopolymers in a controlled quantity. Related results indicate that an appropriate quantity of nano-SiO2 can make the microstructure of fly ash-based geopolymers denser and produce higher mechanical strength. In this study, based on the mechanism of geopolymerization, the effects of nano-SiO2 on the properties of fly ash-based geopolymers including compressive strength, microstructure, hardening properties, shear bond strength, durability, and practical applications have been summarized. This study can provide a basis for understanding the effects of nano-SiO2 on the mechanical properties and durability of fly ash-based geopolymers.

Fast proton-selective transport through covalent organic frameworks in aqueous phase

Covalent organic frameworks (COFs) are expected to be promising candidates as the building block for proton-exchange membranes (PEMs) due to their ordered well-defined nanopore structures with high density and tunable sizes. However, the mechanism of proton-selective transport through COF membranes is still unraveled. We herein investigate the proton-selective transport behaviors through four types of COFs in the aqueous phase. Proton can transport through COF membranes whose effective pore size >8 Å with low free energy barriers of <10 kJ mol−1. Furthermore, molecular analyses manifest that nucleophilic sites on the pore-wall can provide additional pathways for proton and promote the vehicular and Grotthuss transports via increasing the quantities and durability of in-pore hydrogen bonds. This dramatically reduces the energy barrier from ∼42 to ∼12 kJ mol−1 for proton transport especially under confinement (effective pore size <4 Å). Meanwhile, all COF membranes show relatively high methanol penetration barriers. Therefore, COFs with nucleophilic sites or relatively large pores can provide both high proton conductivity (16–60 S m−1) and selectivity (>1 × 104). The revealed mechanisms in this work are expected to not only increase our understandings of proton transport, but also help to design next-generation PEMs with exceptional permselectivity.

A new protocol for rapid assessment of bond durability of bio-based pipes: bamboo winding composite pipe as a case study

A new protocol for rapid assessment of bond durability of bio-based pipes: bamboo winding composite pipe as a case study

Effect of Clinically Relevant Smear Layers and pH of Universal Adhesives on Dentin Bond Strength and Durability.

To evaluate the effects of different smear layers on the microtensile bond strength (µTBS) of a reference two-step self-etch adhesive and two universal adhesives. Mid-coronal dentin of 90 teeth was exposed and divided into three bur groups (coarse diamond, fine diamond, or tungsten carbide). Each bur-prepared group was further divided into three adhesive groups: Clearfil SE Bond (SE, Kuraray Noritake), Single Bond Universal (SB; 3M Oral Care), and G-Premio Bond (GP, GC). After adhesive application, 4-mm-thick resin composites were built up. Half of the teeth in each bur-adhesive group were used in immediate µTBS testing, and the others were tested after thermal aging (n = 5). Rectangular sticks were prepared using a low-speed diamond saw. For each tooth, 6 central sticks were used in the µTBS test. Statistical analysis was performed using three-way ANOVA and Bonferroni tests (α = 0.05). SE presented higher µTBS than universal adhesives and SB presented higher µTBS than GP regardless of dentin surface preparation and thermal aging (p ˂ 0.05). For SE and SB, the tungsten carbide bur demonstrated higher immediate and aged µTBS than did the extra-fine diamond bur (p ˂ 0.05). The immediate µTBS was similar for GP with all bur types (p ˃ 0.05); the tungsten carbide and extra-fine diamond burs presented higher µTBS than did the coarse-diamond bur after thermal aging (p ˂ 0.05). Dentin surface preparation and adhesive type had significant effects on µTBS. The smear layer created with an extra-fine diamond or tungsten carbide bur is favorable when mild and ultra-mild self-etch adhesives are used.

Interaction of silane with 10-MDP on affecting surface chemistry and resin bonding of zirconia

ObjectiveTo investigate the effect of silane contents on their chemical interaction with 10-methacryloyloxydecyl-dihydrogen phosphate (MDP), and affecting the bonding of MDP to zirconia by time-of-flight secondary ion mass spectrometry (TOF-SIMS) and solid-state nuclear magnetic resonance (SSNMR) spectroscopy. MethodsZirconia (Cercon ht, Dentsply) slabs were prepared and fully sintered. Experimental primers SE-5 and SE-10 were formulated by adding 5 wt% and 10 wt% γ-methacryloxypropyltrimethoxysilane to an MDP-based primer SE BOND (SE), respectively. SE, SE-5, and SE-10 were applied on the assigned zirconia slabs. The chemical compositions on the surface and adhesive interfaces were examined by TOF-SIMS in a depth-profiling mode. Hydrophilicity and resin affinity of treated zirconia were analyzed. The bond strengths to resin cylinder were examined either after 24-h storage or thermocycles. In addition, zirconia powders treated with three primers were assessed by SSNMR spectrometry for the adsorption of MDP. ResultsTOF-SIMS analysis showed that SE treatment generated the greatest amount of P-O-Zr related ions, which reduced in SE-5 and SE-10 groups. The 3D ion-images illustrated the generation of ZrO2(OH)- ions with silane contents. The SSNMR analysis revealed that the chemical bonding was mainly P-O-Zr ionic bonds in SE but shifted to P-OH-Zr hydrogen bonds in SE-5 and SE-10. SE-5 and SE-10 treated zirconia presented higher hydrophilicity and affinity to resin compared to Zr did. SE showed the highest initial bond strength which significantly decreased after thermocycling. SignificanceMDP adsorption onto zirconia via P-O-Zr ionic bond promotes bonding with resin. The silane enhances the hydroxylation of zirconia and impairs the adsorption of MDP, but does not adversely affect the bond durability.

Effect of grape seed extract on the bond strength and adhesion durability of universal adhesive to dentin

The effects of grape seed extract (GSE) on the microtensile bond strength (µTBS) and resin-dentin bond durability of universal adhesive to dentin were investigated, while the resin-dentin interface was evaluated using a scanning electron microscope (SEM). Flat occlusal dentin surfaces of 80 sound human molars assigned to, control and GSE-pretreated groups & further divided into etch-and-rinse (E&R) and self-etch (SE) adhesion subgroups. In each subgroup, molars tested immediately (t0; n = 10) & after 6 months (t6; n = 10). In GSE-pretreated group, 10% GSE was prepared in hot water & then used for 1 min pretreatment after etching (15s) in the E&R subgroup or before application of adhesion in the SE subgroup. Composite build-ups made incrementally, and dentin beams sectioned and tested for µTBS at the baseline (24 h) and 6 months. Sections were obtained for SEM analysis. In the 6-month treatment, beams stored in artificial saliva, subjected to thermal cycling, and then tested. The failure modes of fracture surfaces were identified with a stereomicroscope. Comparing the t0 and t6 timepoints, significant reduction in µTBS in all groups compared with their respective controls after aging, but the percentage of bond loss due to aging in the GSE-pretreated groups was less than controls. Most failure modes were mixed. GSE (10%) pretreatment for 1 min before adhesion enhanced the durability of the resin-dentin bond but did not completely eliminate loss of bond strength.

Bond Durability of a Repaired Resin Composite Using a Universal Adhesive and Different Surface Treatments.

To evaluate the long-term effect of different surface treatments on the repair microtensile bond strength (µTBS) of resin composite using a universal adhesive. Thirty-six resin composite blocks were fabricated and aged in 37°C distilled water for 1 month. The blocks were randomly assigned to different surface treatments: no treatment (control); diamond bur grinding (D); diamond bur + phosphoric acid cleaning (DP); diamond bur + silane application (DSi); diamond bur + phosphoric acid + silane (DPSi); and grit blasting with 50 µm H3PO4 particles + phosphoric acid + silane (APSi). Thereafter, Single Bond Universal adhesive was applied and repaired with the same composite. Composite-composite stick-shaped specimens were fabricated and subjected to the µTBS test either after 37°C water storage for 24 h or thermocycling for 10,000 cycles. Roughness of different surface-prepared specimens was measured by profilometer. Data were analysed using ANOVA and Duncan's post-hoc test (α = 0.05). Failure mode and micromorphology of different surface-prepared specimens were observed with SEM and EDS analysis. The highest µTBS was found in DPSi group at 24 h, and was significantly higher than others. The bond strengths in all thermocycled groups were significantly lower than those measured at 24 h. The highest µTBS was also found in the DPSi group, but this did not significantly differ from the DSi group. Thermocycling significantly reduced the repair bond strength. Diamond bur roughening with application of silane and universal adhesive yielded the highest repair bond strength for the aged resin composite.

Clinical and OCT assessment of application modes of a universal adhesive in a 12-month RCT

ObjectivesTo evaluate a universal adhesive clinically using FDI criteria and by optical coherence tomography (OCT). MethodsIn 50 patients, three or four non-carious cervical lesions (NCCL) were restored with composite (Venus® Diamond Flow, Kulzer) using iBond® Universal (iBU, Kulzer) applied in self-etch (iBU-SE, n = 50), selective-enamel-etch (iBU-SEE, n = 29) or etch-and-rinse mode (iBU-ER, n = 50) and the reference OptiBond™ FL (OFL, Kerr, n = 50). Restorations were imaged by SD-OCT. The weighted mean length of interfacial adhesive defects (AD, %) was quantified per restoration immediately after placement (t0), simultaneously with clinical assessment (FDI criteria) after 14 days (t1), 6 (t2) and 12 months (t3). Data were statistically analyzed (McNemar-/Wilcoxon-/Mann-Whitney-U test (α = 0.05), Kaplan-Meier survival curves). ResultsAfter 12 months, cumulative failure rates were lower with iBU-SE (0.0%; p = 0.016), iBU-SEE (0.0%; p = 0.125), and iBU-ER (2.1%; p = 0.070; loss t3) compared to OFL (16.7%; losses t2, t3). Generally, marginal adaptation decreased (pi < 0.001) and marginal staining increased (pi ≤ 0.031), without significant group differences (pi > 0.064). AD increased in all groups (pi < 0.001). At enamel, AD appeared more extended with iBU-SE vs. iBU-SEE (t2-t3; pi ≤ 0.005), iBU-ER (t1-t3; pi ≤ 0.051) and OFL (t0-t3; pi ≤ 0.018). At dentin/cement iBU generally caused fewer defects than OFL (t1-t3; pi ≤ 0.010) and with SE vs. ER (t2-t3; pi = 0.010). ConclusionsIn NCCLs, iBU generally provides a more durable bond than OFL. Recommended mode is SEE. Clinic and OCT provided comparable results. OCT has higher statistical power, shows group differences earlier and specifically for the different hard tooth tissues. Clinical SignificanceThe universal adhesive iBU was superior against the reference OFL in NCCLs. It can be recommended with SEE. Evaluation of interfacial adhesive defects by OCT seems to allow early prediction of adhesives' clinical performance.

A Novel Chemical Binding Primer to Improve Dentin Bonding Durability

The dentin collagen matrix that is not completely enveloped by resin adhesive is vulnerable to degradation by intrinsic collagenases during the etch-and-rinse process, which contributes to the deterioration of the bonding interface. Current commercial adhesives have no functional components that can form covalent bonds to the dentin collagen matrix. In this study, a photocurable aldehyde, 4-formylphenyl acrylate (FA), was synthesized and for the first time applied as a primer in adhesive dentistry to covalently bind to collagen. Experimental groups with different concentrations of FA (1%, 3%, 5%, 7%, 9%) were prepared as primers. The cytotoxicity was evaluated by live/dead-cell staining and thiazolyl blue tetrazolium bromide assay. The interaction of FA with collagen was examined by attenuated total reflection Fourier transform infrared spectroscopy, hydroxyproline release under the degradation of type I collagenase, and thermogravimetric analysis. An optimal group was selected based on the degree of conversion of 2 universal adhesives and further divided depending on the treatment time (20 s, 30 s, 1 min, 2 min). The bonding performances were evaluated by microtensile strength before and after aging. Finally, the bonding interface was observed under confocal laser scanning microscopy and scanning electron microscope. The results indicated that FA demonstrated good biocompatibility, dentin modification capability, and infiltration. It not only effectively cross-linked dentin collagen to improve its stability against enzymatic hydrolysis and modify the adhesive interface but also potentially acted as a diluting monomer to induce deep penetration of adhesive resin monomers into the dentin. The bonding strength after aging was improved without jeopardizing the degree of conversion of 2 commercial adhesives. Such prominent advantages of using FA to improve the bonding performance promotes its further application in adhesive dentistry.

Effects of Sulfate and Sulfuric Acid on Efficiency of Geopolymers as Concrete Repair Materials.

Various geopolymer mortars (GPMs) as concrete repairing materials have become effective owing to their eco-friendly properties. Geopolymer binders designed from agricultural and industrial wastes display interesting and useful mechanical performance. Based on this fact, this research (experimental) focuses on the feasibility of achieving a new GPM with improved mechanical properties and enhanced durability performance against the aggressive sulfuric acid and sulfate attacks. This new ternary blend of GPMs can be achieved by combining waste ceramic tiles (WCT), fly ash (FA) and ground blast furnace slag (GBFS) with appropriate proportions. These GPMs were designed from a high volume of WCT, FA, and GBFS to repair the damaged concretes existing in the construction sectors. Flexural strength, slant shear bond strength, and compatibility of the obtained GPMs were compared with the base or normal concrete (NC) before and after exposure to the aggressive environments. Tests including flexural four-point loading and thermal expansion coefficient were performed. These GPMs were prepared using a low concentration of alkaline activator solution with increasing levels of GBFS and FA replaced by WCT. The results showed that substitution of GBFS and FA by WCT in the GPMs could enhance their bond strength, mechanical characteristics, and durability performance when exposed to aggressive environments. In addition, with the increase in WCT contents from 50 to 70%, the bond strength performance of the GPMs was considerably enhanced under sulfuric acid and sulfate attack. The achieved GPMs were shown to be highly compatible with the concrete substrate and excellent binders for various civil engineering construction applications. It is affirmed that the proposed GPMs can efficiently be used as high-performance materials to repair damaged concrete surfaces.

Bond durability and surface states of titanium, Ti-6Al-4V alloy, and zirconia for implant materials.

Screw-retained implant crowns used as dental implants comprise a zirconia coping and titanium base bonded using resin cement. These devices are prone to debonding failures. This study investigated the bond characteristics of implant materials based on shear bond strength (SBS) and surface characteristics. Chemically pure (CP) titanium grade-4 (Ti), Ti-6Al-4V alloy (Ti-6Al-4V), and tetragonal polycrystalline zirconia (zirconia) were evaluated as adherent materials. Plates of each material were polished, primed for the respective resin cements, and cemented using either methyl methacrylate-based resin cement (Super-Bond) or composite-based resin cement (Panavia). The cemented samples were subjected to 10,000 thermocycles alternating between 5 and 55 °C, and the SBS were obtained before and after thermocycling. The sample surfaces were characterized based on surface observations, roughness, and free energy (SFE). The SBSs of all materials bonded using Panavia were significantly compromised during thermocycling and reached zero. Although the SBSs of Ti and Ti-6Al-4V bonded using Super-Bond were not significantly affected by thermocycling, those of zirconia decreased significantly. The bond durability between zirconia and Super-Bond was improved via alumina air-abrasion, which caused no significant loss of SBS after thermocycling. Surface analyses of the air-abraded zirconia validated these results and confirmed that its surface roughness and SFE were significantly increased. The bond durability between resin cement and zirconia was lower than that between Ti and Ti-6Al-4V. The alumina air-abrasion pretreatment of zirconia improved the SFE and surface roughness, thereby enhancing bond durability.

51 - Bonding Durability of Resin Cement to Lithium Disilicate Glass Ceramics

To obtain reliable adhesion of resin cement to glass ceramics, it is generally known that it is important to apply a silane coupling agent to glass ceramics surface to make its surface has chemically bonding ability. Currently, there are several types of commercial resin cement system with different approach to provide silane coupling agent, such as, prosthesis primer, mixed in bonding agent, or compounded in cement paste. The purpose of this study is to evaluate the bond durability of several resin cement systems to lithium disilicate glass ceramics (LDS) to find reliable system with silane coupling ability. 3 resin cement systems, G-CEM ONE (GO, GC Corporation) with G-Multi Primer (GMP, GC Corporation) which is prosthesis primer included silane coupling agent, PANAVIA SA Cement Universal (PSU, Kuraray) which compounded silane coupling agent in cement paste, and RelyX Universal (RXU, 3 M) with Scotchbond Universal Plus Adhesive(SBU+, 3 M) which is bonding agent mixed silane coupling agent in it were examined. Initial LiSi Block (LiSi, GC Corporation) was used as LDS in this study. LiSi were embedded with acrylic resin. Adhesive surface was finished with 600-grit SiC paper (#600) or hydrofluoric acid (HF)[BISCO PORCELAIN ETCHANT 9.5% HF]. Bonding area(3.0mm-diameter) and cement thickness(0.1mm-thickness) were defined by plastic-tape. Stainless-steel rod was bonded against the bonding area by each resin cement system according to manufacturers instruction in self-curing mode. Bonded specimens were stored in 37 C distilled water for 24 hours(24 h). In case of thermocycling, they were placed under thermocycling condition(5-55 C for 5000cycles:TC5000). Shear Bond strength was tested with universal test equipment (SHIMADZU AG-IC, crosshead-speed 1 mm/min, N=5). Data were statistically analyzed by Tukey-Krame. In case of GO with GMP, there were no significant differences of SBS between 24 h and TC5000 regardless of surface finish (#600 and HF). On the other hand, in case of PSU and RXU with SBU+, SBS of TC5000 on surface finish of #600 significantly decreased compared with SBS of 24 h. From the results, GO with GMP showed high bond strength and bonding durability regardless of surface finish. In case of #600, its finished surface was relatively smooth and mechanical retention would not be expected, but GO with GMP showed the equivalent bonding durability on #600 compared with HF. It might indicate silane coupling ability in GMP was properly functioned and separate prosthesis primer system can be effective. It is expected that better long term bonding durability to lithium disilicate glass ceramics may be achieved by G-CEM ONE system.

Bond Durability between Bfrp Bars and Seawater Sea Sand Concrete in Freezing-Thawing Environment

Bond Durability between Bfrp Bars and Seawater Sea Sand Concrete in Freezing-Thawing Environment

An aqueous polyisocyanate adhesive with excellent bond durability for engineered wood composites enhanced by polyamidoamine-epichlorohydrin co-crosslinking and montmorillonite hybridization

Recent trends toward mass-timber buildings and tall timber structures necessitate more stringent requirements for the bond durability of adhesives for engineered wood composites. In this work, a cost-effective strategy for manufacturing a novel aqueous polyisocyanate adhesive with excellent hygrothermal resistance for engineered wood composites was produced via co-crosslinking with polyamidoamine-epichlorohydrin (PAE) resin followed by organic–inorganic hybridization with montmorillonite clay (MMC). Test results confirmed that PAE co-crosslinking effectively increased the crosslinking density of aqueous polyisocyanate adhesive meanwhile prolonged working life. Hybridization of PAE-crosslinked polyisocyanate with MMC resulted in compact crosslinked networks and notably increased hygrothermal resistance. Consequently, this novel aqueous polyisocyanate adhesive exhibited excellent bond durability of plywood in terms of a wet aged strength of 1.73 MPa and a strength reduction ratio of only 18.4% after 7 boiling-dry hygrothermal aging cycles, which satisfies the requirements for manufacturing engineered wood composites as good construction and building materials.

Effect of Dentin Biomodification Using Natural Collagen Cross-Linkers on the Durability of the Resin-Dentin Bond and Demineralized Dentin Stiffness

Effect of Dentin Biomodification Using Natural Collagen Cross-Linkers on the Durability of the Resin-Dentin Bond and Demineralized Dentin Stiffness