Cyanoacrylate glue for iatrogenic retinal breaks during vitrectomy in stage 5 familial exudative vitreoretinopathy.

Purpose: To describe the role of cyanoacrylate glue in sealing iatrogenic retinal breaks (IRBs) during vitrectomy in stage 5 familial exudative vitreoretinopathy (FEVR) with funneled retinal detachment (RD). Methods: Nine eyes of nine patients diagnosed as stage 5 FEVR were treated with cyanoacrylate glue for IRBs during vitrectomy from July 2020 to January 2022. The clinical records, including patient information, surgical process, and follow-up examinations, were collected retrospectively. Anatomical outcomes and visual outcomes were summarized. Results: The average age at surgery was 19.6 months (range: 3.8-41.1 months). The mean post-operative follow-up period was 12.5 months (range: 9.8-18.8 months). Before surgery, five eyes had an open-funnel RD and four eyes had a closed-funnel RD. All the preretinal fibroplasia membranes were removed as thoroughly as possible in the nine eyes. IRBs formed at the posterior pole in two eyes and peripheral retina in seven eyes. All the IRBs were sealed successfully by the cyanoacrylate glue when they appeared. At the final post-operative visit, eight eyes had partial retinal reattachment without progression of fibroplasia tissues, while one eye had total retinal redetachment. The rate for stable anatomical outcome was 88.9% (8/9) in this study. The visual testing available for seven eyes demonstrated light perception in five eyes and no light perception in two eyes. No severe perioperative glue-related complications were noted during the follow-ups. Conclusion: The application of cyanoacrylate glue may be an alternative therapy for IRBs in stage 5 FEVR surgeries, while the long-term efficacy and safety still need further investigation.

Effect of Different Adhesive Resin and Composite Veneering Materials on Adhesion to Polyetheretherketone.

OBJECTIVE: To evaluate the effect of different adhesives and veneering resins on the shear bond strength (SBS) of polyetheretherketone (PEEK). METHODS: A total of 138 PEEK specimens were randomly divided into 6 groups according to adhesive material application: Control (C, no application), Adhese Universal (A) (Ivoclar Vivadent, Schaan, Liechtenstein), Gluma Bond Universal (G) (Heraeus Kulzer, South Bend, IN, USA), G-PremioBOND (P) (GC Corporation, Tokyo, Japan), Single Bond Universal (S) (3M, Saint Paul, MN, USA) and visio.link (V) (Bredent, Senden, Germany). Each adhesive group was divided into two subgroups according to the type of veneering material: Estenia direct composite (D) and Gradia Plus indirect composite (IN) (both GC Corporation). After the veneering process, the specimens were aged by thermal cycling. Kruskal-Wallis and Mann-Whitney U tests were used for SBS analysis (P < 0.05). RESULTS: The highest SBS results were obtained in the VIN group, followed by the VD, PD, GIN, AIN, AD, SIN, SD, PIN, GD, CIN and CD groups, respectively (P = 0.001). There were no significant differences in terms of the type of veneering composite when the same adhesive was applied (P > 0.05), except for Gluma Bond Universal (P = 0.009). All the adhesives tested showed clinically acceptable SBS results. CONCLUSION: Visio.link offered the highest adhesion to PEEK, whereas the tested universal adhesives may be used as an alternative to visio.link in clinical settings. It was determined that changing the veneer type has no statistical difference when the same adhesive material is used.

Effect of multi-layer applications of self-etch universal bonding agents on the adhesion of resin composite to enamel.

To evaluate the effect of adhesive coats application on the enamel microtensile bond strength (µTBS) of universal adhesives, morphological etching pattern and their chemical interaction with hydroxyapatite (HA). Two universal adhesives were investigated: Scotchbond Universal (SBU, 3 M) and Prime&Bond Universal (PBU, Dentsply). The adhesives were applied in self-etching mode on bovine enamel (n = 8) in one (1L), two (2L) or three coats (3L) and light-cured as per manufacturers' instructions. As controls adhesives were applied to etched enamel (H3PO4-37% phosphoric acid). Bonded specimens were cut into sticks that were stored in deionized water for 24 h or 6 months prior to µTBS testing. Two-way ANOVA and Tukey's test were used for statistical analysis of bond strength with α = 5%. For morphological SEM analysis, enamel surfaces were treated as aforementioned and immediately rinsed with acetone. The intensity of monomer-calcium salt formation from each treatment was measured via infrared spectroscopy (ATR-FTIR). All treatments presented no significant reduction on µTBS after aging (p > 0.05). However, SBU attained highest µTBS when applied in 3L. PBU showed higher µTBS when applied to H3PO4 etched enamel than 1L or 2L. Etching pattern was enhanced by 3L application, particularly with PBU. Chemical interaction was notably higher for SBU than PBU, with no relevant differences with more layers or prior H3PO4-etching. The application of three adhesive coats of universal adhesives in self-etch mode using may enhance the bonding performance and etching pattern to enamel, surpassing the H3PO4-etched enamel bond for SBU. The chemical interaction with calcium from enamel is not affected by number of coats or prior phosphoric acid etching.

Mechanically Interlocked [an]Daisy Chain Adhesives with Simultaneously Enhanced Interfacial Adhesion and Cohesion.

Adhesives have been widely used to splice and repair materials to meet practical needs of humanity for thousands of years. However, developing robust adhesives with balanced adhesive and cohesive properties still remains a challenging task. Herein, we report the design and preparation of a robust mechanically interlocked [an]daisy chain network (DCMIN) adhesive by orthogonal integration of mechanical bond and 2-ureido-4[1H]-pyrimidone (UPy) H-bonding in a single system. Specifically, the UPy moiety plays dual roles: cross-linking for network formation and multivalent interactions with substrate for strong interfacial bonding. Mechanically interlocked [an]daisy chain, serving as the polymeric backbone of the adhesive, is able to effectively alleviate applied stress and uphold network integrity through synergistic intramolecular motions and thus significantly improve the cohesive performance. Therefore, comparative analyses with the control made of the same quadruple H-bonding network but with non-interlocked [an]daisy chain backbones demonstrate that our DCMIN possesses superior adhesion properties over a wide temperature range. These findings not only contribute to a deep understanding of the structure-property relationships between microscopic mechanical bond motions and macroscopic adhesive properties but also provide a valuable guidance for optimizing design principles of robust adhesives.

An Overview on the Adhesion Mechanisms of Typical Aquatic Organisms and the Applications of Biomimetic Adhesives in Aquatic Environments.

Water molecules pose a significant obstacle to conventional adhesive materials. Nevertheless, some marine organisms can secrete bioadhesives with remarkable adhesion properties. For instance, mussels resist sea waves using byssal threads, sandcastle worms secrete sandcastle glue to construct shelters, and barnacles adhere to various surfaces using their barnacle cement. This work initially elucidates the process of underwater adhesion and the microstructure of bioadhesives in these three exemplary marine organisms. The formation of bioadhesive microstructures is intimately related to the aquatic environment. Subsequently, the adhesion mechanisms employed by mussel byssal threads, sandcastle glue, and barnacle cement are demonstrated at the molecular level. The comprehension of adhesion mechanisms has promoted various biomimetic adhesive systems: DOPA-based biomimetic adhesives inspired by the chemical composition of mussel byssal proteins; polyelectrolyte hydrogels enlightened by sandcastle glue and phase transitions; and novel biomimetic adhesives derived from the multiple interactions and nanofiber-like structures within barnacle cement. Underwater biomimetic adhesion continues to encounter multifaceted challenges despite notable advancements. Hence, this work examines the current challenges confronting underwater biomimetic adhesion in the last part, which provides novel perspectives and directions for future research.

Thermal Stability and Heat Transfer of Polyurethanes for Joints Applications of Wooden Structures.

Wood characterized by desired mechanical properties and wood joining material is essential for creating wooden structures. The polymer adhesives are suitable for such applications due to the possibility of energy dissipation from stresses generated by wooden structures and the elimination of thermal bridging, which are common problems in metal joining materials. This research focuses on the thermophysical properties of the laboratory-prepared flexible and rigid polyurethanes to select an appropriate polymer adhesive. Our results showed that the highest thermal stability was in the case of the new PSTF-S adhesive, which reached 230 °C, but the lowest mass loss in the air environment was around 54% for the PS material. The mean thermal expansion coefficient for F&R PU adhesives was 124-164∙10-6 K-1. The thermal diffusivity of examined adhesives varied between 0.100 and 0.180 mm2s-1. The thermal conductivity, depending on the type of polyurethane, was in the 0.13-0.29 W∙m-1∙K-1 range. The relative decrease in thermal diffusivity after heating the adhesives to 150 °C was from 2% for materials with the lowest diffusivity to 23% for the PU with the highest value of heat transfer. It was found that such data can be used to simulate wooden construction joints in future research.

Deformation-Resistant Underwater Adhesion in a Wide Salinity Range.

Conventional adhesives experience reduced adhesion when exposed to aqueous environments. The development of underwater adhesives capable of forming strong and durable bonds across various wet substrates is crucial in biomedical and engineering domains. Nonetheless, limited emphasis placed on retaining high adhesion strengths in different saline environments, addressing challenges such as elevated osmotic pressure and spontaneous dimensional alterations. Herein, a series of ionogel-based underwater adhesives are developed using a copolymerization approach that incorporates "dynamic complementary cross-linking" networks. Synergistic engineering of building blocks, cross-linking networks, pendant groups and counterions within ionogels ensures their adhesion and cohesion in brine spanning a wide salinity range. A high adhesion strength of ≈3.6 MPa is attained in freshwater. Gratifyingly, steady adhesion strengths exceeding 3.3 MPa are retained in hypersaline solutions with salinity ranging from 50 to 200 g kg-1, delivering one of the best-performing underwater adhesives suitable for diverse saline solutions. A combination of outstanding durability, reliability, deformation resistance, salt tolerance, and self-healing properties showcases the "self-contained" underwater adhesion. This study shines light on the facile fabrication of catechol-free ionogel-based adhesives, not merely boosting adhesion strengths in freshwater, but also broadening their applicability across various saline environments.

Self-Neutralizing Melamine-Urea-Formaldehyde-Citric Acid Resins for Wood Panel Adhesives.

In this study, we used a self-neutralizing system to counteract too acidic a pH, unsuitable for wood adhesives, and tested it on MUF resins augmented by the addition of citric acid or other organic acids, based on the addition of small percentages of hexamine or another suitable organic base to form an acid-base buffer. In this manner, the pH of the adhesive was maintained above the minimum allowed value of 4, and the strength results of wood particleboard and plywood bonded with this adhesive system increased due to the additional cross-linking imparted by the citric acid. Thus, the wood constituents at the wood/adhesive interface were not damaged/degraded by too low a pH, thus avoiding longer-term service failure of the bonded joints. The addition of the buffering system increased the strength of the bondline in both the plywood and particleboard, both when dry and after hot water and boiling water tests. The IB strength of the particleboard was then increased by 15-17% when dry but by 82% after boiling. For the plywood, the shear strengths when dry and after 3 h in hot water at 63 °C were, respectively, 37% and 90% higher than for the control. The improvement in the bonded panel strength is ascribed to multiple reasons: (i) the slower, more regular cross-linking rate due to the action of the buffer; (ii) the shift in the polycondensation-degradation equilibrium to the left induced by the higher pH and the long-term stability of the organic buffer; (iii) the additional cross-linking by citric acid of some of the MUF resin amine groups; (iv) the already known direct linking of citric acid with the carbohydrates and lignin constituents at the interface of the wood substrate; and (v) the likely covalent linking to the interfacial wood constituents of the prelinked MUF-citric acid resin by some of the unreacted citric acid carboxyl groups.

Development and Application of a Lignin-Based Polyol for Sustainable Reactive Polyurethane Adhesives Synthesis.

In response to the environmental impacts of conventional polyurethane adhesives derived from fossil fuels, this study introduces a sustainable alternative utilizing lignin-based polyols extracted from rice straw through a process developed at INESCOP. This research explores the partial substitution of traditional polyols with lignin-based equivalents in the synthesis of reactive hot melt polyurethane adhesives (HMPUR) for the footwear industry. The performance of these eco-friendly adhesives was rigorously assessed through Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), rheological analysis, and T-peel tests to ensure their compliance with relevant industry standards. Preliminary results demonstrate that lignin-based polyols can effectively replace a significant portion of fossil-derived polyols, maintaining essential adhesive properties and marking a significant step towards more sustainable adhesive solutions. This study not only highlights the potential of lignin in the realm of sustainable adhesive production but also emphasises the valorisation of agricultural by-products, thus aligning with the principles of green chemistry and sustainability objectives in the polymer industry.

Principles and Design of Bionic Hydrogel Adhesives for Skin Wound Treatment.

Over millions of years of evolution, nature has developed a myriad of unique features that have inspired the design of adhesives for wound healing. Bionic hydrogel adhesives, capable of adapting to the dynamic movements of tissues, possess superior biocompatibility and effectively promote the healing of both external and internal wounds. This paper provides a systematic review of the design and principles of these adhesives, focusing on the treatment of skin wounds, and explores the feasibility of incorporating nature-inspired properties into their design. The adhesion mechanisms of bionic adhesives are analyzed from both chemical and physical perspectives. Materials from natural and synthetic polymers commonly used as adhesives are detailed regarding their biocompatibility and degradability. The multifunctional design elements of hydrogel adhesives for skin trauma treatment, such as self-healing, drug release, responsive design, and optimization of mechanical and physical properties, are further explored. The aim is to overcome the limitations of conventional treatments and offer a safer, more effective solution for the application of bionic wound dressings.

Versatile Underwater Pressure Sensitive Adhesive: UV Curing Synthesis and Substrate-Independent Adhesion.

The demand for underwater pressure sensitive adhesives (PSAs) is rapidly increasing in fields such as underwater engineering and biomedicine. However, the achievement of underwater adhesion of PSAs remains a challenge because of the hydration layer that hinders the interaction between the adhesive and the substrate. Herein, a new type of underwater PSA was synthesized by the copolymerization of hydrophobic unsaturated poly(1,2-butylene oxide) (UPBO) and hydrophilic itaconic acid monomers using solvent-free ultraviolet curing. The PSA has demonstrated substrate-independent underwater adhesion strengths ranging from 108 to 141 kPa on both hydrophilic (glass, wood, steel) and hydrophobic (PET, PMMA, PTFE) substrates. The underwater adhesion performance of PSA remains stable during 30 adhesion-detachment cycles and incubation in water for 20 days. Notably, PSA shows cytocompatibility, antimicrobial, and degradable properties and can be used for rapid hemostasis of skin wounds. Experimental characterizations confirm that the process of underwater adhesion is achieved by hydrophobic alkyl side chains of the PBO chain segments, which repel water at the adhesive-substrate interface. This study should provide both practical and facile design strategies for multifunctional underwater PSAs that can be used in a variety of applications.

Comparative Evaluation of Microtensile Dentin Bond Strength and Interfacial Micromorphology of Three Universal Adhesives.

OBJECTIVES: To assess and compare the microtensile dentin bond strength (µTBS) and interfacial micromorphology of three universal adhesives. METHODS: 96 human molars were assigned to three universal adhesives: Single Bond Universal (SBU), CLEARFIL Universal Bond Quick (UBQ), and RE-GEN Universal Adhesive (REGEN). Adhesives were applied in self-etch mode. SBU and REGEN were applied following the manufacturers' instructions. UBQ was divided into two subgroups: one following the manufacturer's instructions (UBQ Short) and the other with an extended application time (UBQ Extended). Teeth were restored with nanohybrid resin composite. Specimens were divided into immediate and delayed subgroups. The delayed subgroups were stored for 6 months and subjected to 5000 thermocycles. µTBS was tested, and failure mode was analyzed. Interfacial micromorphology was assessed using a scanning electron microscope. The data were statistically analyzed (p⟨ 0.05). RESULTS: The adhesive choice, aging, and their interaction significantly affected µTBS. SBU exhibited the highest immediate µTBS, comparable to UBQ (Extended) and REGEN, and significantly higher than UBQ (Short). In delayed testing, SBU outperformed the other adhesives. CONCLUSIONS: Aging negatively affected the µTBS of UBQ and REGEN, while SBU wasn't affected. The quick application concept of UBQ deteriorated its µTBS compared to the extended application time.

A review of bioinspired dry adhesives: from achieving strong adhesion to realizing switchable adhesion.

In the early twenty-first century, extensive research has been conducted on geckos' ability to climb vertical walls with the advancement of microscopy technology. Unprecedented studies and developments have focused on the adhesion mechanism, structural design, preparation methods, and applications of bioinspired dry adhesives. Notably, strong adhesion that adheres to both the principles of contact splitting and stress uniform distribution has been discovered and proposed. The increasing popularity of flexible electronic skins, soft crawling robots, and smart assembly systems has made switchable adhesion properties essential for smart adhesives. These adhesives are designed to be programmable and switchable in response to external stimuli such as magnetic fields, thermal changes, electrical signals, light exposure as well as mechanical processes. This paper provides a comprehensive review of the development history of bioinspired dry adhesives from achieving strong adhesion to realizing switchable adhesion.

Effects of immersion in 4-methacryloyloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butyl borane resin-activated liquid on microtensile bond strength of root canal dentin.

Background/purpose: 4-methacryloyloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butyl borane (4-META/MMA-TBB) resin is used for indirect restorations. We aimed to evaluate effects of immersion in 4-META/MMA-TBB-activated liquid on the bond strength of root canal dentin. Materials and methods: We used freshly extracted single-rooted human teeth. After decoronation, each root was vertically sectioned into halves; their dentin walls were polished and flattened. The control group underwent dentin treatment with Green Activator. The immersion group was treated with Green Activator and Teeth Primer and immersed in 4-META/MMA-TBB-activated liquid. After bonding the resin blocks with Super-Bond, microtensile bond strength (µTBS) tests were performed (n = 6), and fracture surfaces were analyzed. Before surface treatment, dentin was immersed in a sodium fluorescein solution for 3 h, and resin blocks were bonded with Super-Bond with rhodamine B as in the bond strength test. The bonded cross section was observed using confocal laser scanning microscopy (CLSM). Results: µTBS was significantly higher in the immersion group than in the control group (61.5 [51.3-66.7] vs. 33.0 [20.4-57.8] MPa; P < 0.05). Fracture mode analysis showed that, compared with the control group, the immersion group had a significantly lower rate of adhesive failure at the dentin interface and a significantly higher rate of cohesive failure in Super-Bond (P < 0.01). CLSM showed a water droplet-like accumulation of fluorescein dye above the hybrid layer in the control group, not in the immersion group. Conclusion: Immersion in a 4-META/MMA-TBB-activated liquid inhibited water exudation from the root canal dentin and improved the bond strength.

Harnessing Biomimicry for Controlled Adhesion on Material Surfaces.

Nature serves as an abundant wellspring of inspiration for crafting innovative adhesive materials. Extensive research is conducted on various complex forms of biological attachment, such as geckos, tree frogs, octopuses, and mussels. However, significant obstacles still exist in developing adhesive materials that truly replicate the behaviors and functionalities observed in living organisms. Here, an overview of biological organs, structures, and adhesive secretions endowed with adhesion capabilities, delving into the intricate relationship between their morphology and function, and potential for biomimicry are provided. First, the design principles and mechanisms of adhesion behavior and individual organ morphology in nature are summarized from the perspective of structural and size constraints. Subsequently, the value of engineered and bioinspired adhesive materials through selective application cases in practical fields is emphasized. Then, a forward-looking gaze on the conceivable challenges and associated opportunities in harnessing biomimetic strategies and biological materials for advancing adhesive material innovation is highlighted and cast.

Rigid-Flexible Coupled Dendritic Molecule Doping: General Approach to Activate Commercial Polymers into Harsh Condition- Tolerant Multi-Reusable Strong Supramolecular Adhesives.

Developing functional adhesives combining strong adhesion, good recyclability and diverse harsh-condition adaptability is a grand challenge. Here, we introduce a general dendritic molecule doping strategy to activate commercial polymers into a new family of supramolecular adhesives integrating high adhesion strength, ultralow temperature, water resistant and multi-reusable properties. Our method involves rational design of a new rigid-flexible coupled dendritic molecule - M4C8OH as a versatile dopant, while simple M4C8OH doping into commercial polymers can modulate internal and external non-covalent interaction to enable H-bonding enhanced interchain cross-linking for tough cohesion along with enhanced interphase interaction. This endows 20 wt% M4C8OH-doped polycaprolactone (PCL) adhesives (PCL-M4C8OH) with improved adhesion strength on various substrates with the maximum increase up to 2.87 times that of PCL. In particular, the adhesion strengths of PCL-M4C8OH on polymethyl methacrylate at 25 °C and -196 °C reach 4.67 and 3.58 MPa - 1.9 and 2.3 times those of PCL and superior to diverse commercial adhesives and most reported adhesives. PCL-M4C8OH also displays markedly-improved multi-usability and tolerance against ultralow temperature and diverse wet environments. Mechanism studies reveal the crucial role of  M4C8OH molecular structures toward superior adhesion. Our method can be expanded to other polymer matrices, yielding diverse new supramolecular adhesives.

The efficacy and safety of CT-guided localization of pulmonary nodules by medical adhesives containing methylene blue before surgery.

Background: The accurate preoperative localization of pulmonary nodules is essential for a successful video-assisted thoracic surgery (VATS). The aim of this research was to clarify the efficacy and safety of CT-guided localization of pulmonary nodules by mixture of methylene blue and medical adhesive. Methods: Between January 2020 and January 2021, 103 subjects who have received the CT-guidance pulmonary nodules localization operation were included and retrospectively analyzed. The data on efficiency and complications of preoperative localization using medical adhesives mixed with methylene blue mixture were collected and analyzed. Results: 103 patients with 111 localized pulmonary nodules were included, 95 of whom had one nodule and 8 of whom had two nodules. The nodule localization success rate reaches as high as 100 %. The mean diameter of pulmonary nodules was 9.50 ± 3.67 mm. The mean distance of pulmonary nodule and pleural surface was 19.95 ± 14.92 mm. The mean depth of localized adhesive in the lung parenchyma was 18.99 ± 11.62 mm, and the mean time required for localization was 16.98 ± 5.72 min. The average time from the nodule localization to VATS surgery was 16.97 ± 7.34 h. The common complications of localization were minor pulmonary hemorrhage (9.74 %) and mild pneumothorax (15.53 %). Besides, pulmonary hemorrhage was related with depths of medical adhesives and nodules in lung parenchyma (p = 0.018 and 0.002, respectively). Conclusion: Medical adhesive mixed with methylene blue is safe and effective in pulmonary nodules localization for VATS, and surgeons have flexibility in scheduling the procedure.

Hypothesizing the Oleic Acid-Mediated Enhanced and Sustained Transdermal Codelivery of Pregabalin and Diclofenac Adhesive Nanogel: A Proof of Concept.

Pregabalin and diclofenac diethylamine are anti-inflammatory molecules that are effective in relieving inflammation and pain associated with musculoskeletal disorders, arthritis, and post-traumatic pain, among others. Intravenous and oral delivery of these two molecules has their limitations. However, the transdermal route is believed to be an alternate viable option for the delivery of therapeutic molecules with desired physicochemical properties. To this end, it is vital to understand the physicochemical properties of these drugs, dosage, and strategies to enhance permeation, thereby surmounting the associated constraints and concurrently attaining a sustained release of these therapeutic molecules when administered in combination. The present work hypothesizes the enhanced permeation and sustained release of Pregabalin and diclofenac diethylamine across the skin, entrapped in the adhesive nano-organogel formulation, including permeation enhancers. The solubility studies of Pregabalin and diclofenac diethylamine in combination were performed in different permeation enhancers. Oleic acid was optimized as the best permeation enhancer based on in vitro studies. Pluronic organogel containing Pregabalin and diclofenac diethylamine with oleic acid was fabricated. Duro-Tak® (87-2196) was added to the organogel formulation as a pressure-sensitive adhesive to sustain the release profile of these two therapeutic molecules. The adhesive organogel was characterized for particle size, scanning electron microscopy, and contact angle measurement. The HPLC method developed for the quantification of the dual drug showed a retention time of 3.84 minutes and 9.69 minutes for pregabalin and diclofenac, respectively. The fabricated nanogel adhesive formulation showed the desired results with particle size and contact angle of 282 ± 57 nm and ≥120°, respectively. In vitro studies showed the percentage cumulative release of 24.90 ± 4.65% and 33.29 ± 4.81% for pregabalin and diclofenac, respectively. In order to accomplish transdermal permeation, the suggested hypothesis of fabricating PG and DEE nano-organogel in combination with permeation enhancers will be a viable drug delivery method. In comparison to a traditional gel formulation, oleic acid as a permeation enhancer increased the penetration of both PG and DEE from the organogel formulation. Notably, the studies showed that the use of pressure-sensitive adhesives enabled the sustained release of both PG and DEE.Therefore, the results anticipated the hypothesis that the transdermal delivery of adhesive PG and DEE-based nanogel across the human skin can be achieved to inhibit inflammation and pain.

Kinetic Study of Anaerobic Adhesive Curing on Copper and Iron Base Substrates.

Anaerobic adhesives (AAs) cure at room temperature in oxygen-deprived spaces between metal substrates. The curing process is significantly influenced by the type of metal ions present. This study investigates the curing kinetics of a high-strength AA on iron and copper substrates using differential scanning calorimetry (DSC). The activation energy and kinetic parameters were determined with different empiric models, revealing that curing on copper is faster and more complete compared to iron. The findings suggest that copper ions lower the activation energy required for curing, enhancing the adhesive's performance. This research addresses the gap in understanding how metal ions affect AA curing kinetics, offering valuable insights for optimizing adhesive formulations for industrial applications.

Effect of Different Primers on the Shear Bond Strength of Orthodontic Brackets Bonded to Reinforced Polyetheretherketone (PEEK) Substrate.

This in vitro study assessed the effect of different primers on the shear bond strength (SBS) and adhesive remnant index (ARI) of orthodontic brackets bonded to reinforced polyetheretherketone (PEEK) substrate. A total of 40 specimens were randomly distributed to two groups based on the primer used for orthodontic bonding: group 1 (control)-Transbond XT adhesive with Visio.link primer and group 2 (test)-orthodontic adhesive (Transbond XT) with traditional orthodontic primer. After bonding, specimens were thermocycled followed by SBS testing and ARI scoring of debonded specimens. Data were analyzed using the unpaired independent t-test and the Chi-square test. Group 1 specimens showed significantly higher SBS values (21.38 ± 1.48 MPa) compared to group 2 specimens (18.63 ± 1.29 MPa) (p < 0.0001). Adhesive remnant index scores showed no significant variations in bond failure modes and distributions between groups. The SBS obtained by the tested primers exceeded the clinically recommended value. Consequently, there is a comparable clinical application for both tested primers in orthodontic bonding, especially the traditional orthodontic primer, where the availability of Visio.link in clinical practice is not ensured.