Displaying publications 41 - 60 of 92 in total

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  1. Fulltext Effect of thermocycling on the compressive strength of selected luting cements
    Al-Khadim Aws H., Abdullah H., Al-Ani Sarah T.
    International Medical Journal Malaysia, 2018;17(3):75-80.
    MyJurnal
    Introduction: The purpose of this in vitro study was to evaluate the effect of thermocycling on the compressive strength of selected luting cements. Material and methods: 5 types of luting cements were tested. A total of thirty cylindrical specimens measuring 6mm in height and 4mm in diameter were prepared for each type of cement which were then divided into two groups ie Group 1: Exposure, and Group 2: Control. Both groups were stored in distilled water at 37°C for 24 hours. Group 1 was subjected to 500 cycles in a thermocycling baths of 5ºC and 55ºC with 20 seconds in each bath. Group 2 was not exposed to thermocycling procedure. The compressive strength for each cement type was determined by using a universal testing machine. Results: Resin adhesive cement had the highest compressive strength; followed by conventional glass ionomer cement (GIC) whilst resin modified GIC was the least. Thermocycling had no significant effect on the compressive strength of RelyXTM ARC and Fuji I (p>0.05), but a significant effect on Fuji I CAPSULE, Fuji CEM, Fuji Plus CAPSLUE (p
    Matched MeSH terms: Adhesives
  2. Valorization of Technical Lignin for the Production of Desirable Resins with High Substitution Rate and Controllable Viscosity
    Pang B, Lam SS, Shen XJ, Cao XF, Liu SJ, Yuan TQ, et al.
    ChemSusChem, 2020 Sep 07;13(17):4446-4454.
    PMID: 32118355 DOI: 10.1002/cssc.202000299
    The valorization of lignin to replace phenol is significant in the production of phenolic resins. However, a great challenge is to produce lignin-based resin (LR) with a suitable viscosity and high substitution rate of lignin to phenol. In this study, LRs were produced using hardwood technical lignin derived from the pulping industry. Structural analysis of the LRs indicated that the unsubstituted para and ortho carbon atoms of the aromatic ring influenced the curing temperature and activation energy of the resins. The curing kinetics and thermal decomposition study implied that urea and methylene groups in cured LRs were significant factors that affected the thermal stability negatively. The prepared LRs showed desirable features if used as adhesives to make plywood. This is the first approach in which a substitution rate of up to 65 % is achieved for low-reactive-site hardwood lignin, which provides a solution to the challenge of the simultaneous realization of the high addition of lignin and the adaptive viscosity of resins.
    Matched MeSH terms: Adhesives
  3. Fulltext Experimental Investigation of the Effect of the Driving Voltage of an Electroadhesion Actuator
    Koh KH, Sreekumar M, Ponnambalam SG
    Materials (Basel), 2014 Jun 25;7(7):4963-4981.
    PMID: 28788114 DOI: 10.3390/ma7074963
    This paper investigates the effect of driving voltage on the attachment force of an electroadhesion actuator, as the existing literature on the saturation of the adhesive force at a higher electric field is incomplete. A new type of electroadhesion actuator using normally available materials, such as aluminum foil, PVC tape and a silicone rubber sheet used for keyboard protection, has been developed with a simple layered structure that is capable of developing adhesive force consistently. The developed actuator is subjected to the experiment for the evaluation of various test surfaces; aluminum, brick, ceramic, concrete and glass. The driving high voltage is varied in steps to determine the characteristics of the output holding force. Results show a quadratic relation between F (adhesion force) and V (driving voltage) within the 2 kV range. After this range, the F-V responses consistently show a saturation trend at high electric fields. Next, the concept of the leakage current that can occur in the dielectric material and the corona discharge through air has been introduced. Results show that the voltage level, which corresponds to the beginning of the supply current, matches well with the beginning of the force saturation. With the confirmation of this hypothesis, a working model for electroadhesion actuation is proposed. Based on the experimental results, it is proposed that such a kind of actuator can be driven within a range of optimum high voltage to remain electrically efficient. This practice is recommended for the future design, development and characterization of electroadhesion actuators for robotic applications.
    Matched MeSH terms: Adhesives
  4. Fulltext Embolisation of a bronchial artery of anomalous origin in massive haemoptysis
    Md Ralib AR, Han NT, Hin HS, Muda AS
    Malays J Med Sci, 2010 Jul;17(3):55-60.
    PMID: 22135550 MyJurnal
    Massive haemoptysis is the most dreaded of all respiratory emergencies. Bronchial artery embolisation is known to be a safe and effective procedure in massive haemoptysis. Bronchial artery of anomalous origin presents a diagnostic challenge to interventional radiologists searching for the source of haemorrhage. Here, we report a case of massive haemoptysis secondary to a lung carcinoma with the bronchial artery originating directly from the right subclavian artery. This artery was not evident during the initial flush thoracic aortogram. The anomalous-origin bronchial artery was then embolised using 15% diluted glue with good results. An anomalous-origin bronchial artery should be suspected if the source of haemorrhage is not visualised in the normally expected bronchial artery location.
    Matched MeSH terms: Adhesives
  5. Fulltext Imaging findings of extensive splenic infarction after cyanoacrylate injection for gastric varices--a case report
    Chan RS, Vijayananthan A, Kumar G, Hilmi IN
    Med J Malaysia, 2012 Aug;67(4):424-5.
    PMID: 23082456
    Endoscopic injection of N-Butyl-2-cyanoacrylate is a widely accepted treatment for esophagogastric varices. This procedure is commonly associated with minor complications which include transient pyrexia and abdominal discomfort. Serious vascular complications secondary to systemic embolization of cyanoacrylate have rarely been reported. We describe the CT findings of extensive splenic infarction in a patient following cyanoacrylate injection for gastric varices.
    Matched MeSH terms: Tissue Adhesives/adverse effects*
  6. Liquefaction of kenaf (Hibiscus cannabinus L.) core for wood laminating adhesive
    Juhaida MF, Paridah MT, Mohd Hilmi M, Sarani Z, Jalaluddin H, Mohamad Zaki AR
    Bioresour Technol, 2010 Feb;101(4):1355-60.
    PMID: 19833509 DOI: 10.1016/j.biortech.2009.09.048
    A study was carried out to produce polyurethane (PU) as a wood laminating adhesive from liquefied kenaf core (LKC) polyols by reacting it with toluene-2,4-diisocyanate (TDI) and 1,4-butanediol (BDO). The LKC polyurethane (LKCPU) adhesive has a molecular weight (MW) of 2666, viscosity of 5370 mPa s, and solids content of 86.9%. The average shear strength of the rubberwood (RW) bonded with LKCPU adhesive was 2.9 MPa. Most of the sheared specimens experienced a total adhesive failure. The formation of air bubbles through the liberation of carbon dioxide was observed to reduce the adhesive penetration and bonding strength which was obviously seen on the sheared specimens. The percentage of catalyst used can be varied based on the usage and working time needed. Nonetheless, the physical properties of LKCPU produced in this work had shown good potential as edge-bonding adhesive.
    Matched MeSH terms: Adhesives/chemistry*
  7. Hardness, flexural strength, and flexural modulus comparisons of three differently cured denture base systems
    Ali IL, Yunus N, Abu-Hassan MI
    J Prosthodont, 2008 Oct;17(7):545-9.
    PMID: 18761582 DOI: 10.1111/j.1532-849X.2008.00357.x
    This study compared the surface hardness, flexural strength, and flexural modulus of a light- and heat-cured urethane dimethacrylate (UDMA) to two conventional polymethyl methacrylate (PMMA) denture base resins. The effect of less-than-optimal processing condition on the hardness of internal and external surfaces of UDMA specimens was also investigated.
    Matched MeSH terms: Light-Curing of Dental Adhesives*
  8. Dynamic Interfacial Adhesion through Cucurbit[n]uril Molecular Recognition
    Liu J, Tan CSY, Scherman OA
    Angew Chem Int Ed Engl, 2018 07 16;57(29):8854-8858.
    PMID: 29663607 DOI: 10.1002/anie.201800775
    Supramolecular building blocks, such as cucurbit[n]uril (CB[n])-based host-guest complexes, have been extensively studied at the nano- and microscale as adhesion promoters. Herein, we exploit a new class of CB[n]-threaded highly branched polyrotaxanes (HBP-CB[n]) as aqueous adhesives to macroscopically bond two wet surfaces, including biological tissue, through the formation of CB[8] heteroternary complexes. The dynamic nature of these complexes gives rise to adhesion with remarkable toughness, displaying recovery and reversible adhesion upon mechanical failure at the interface. Incorporation of functional guests, such as azobenzene moieties, allows for stimuli-activated on-demand adhesion/de-adhesion. Macroscopic interfacial adhesion through dynamic host-guest molecular recognition represents an innovative strategy for designing the next generation of functional interfaces, biomedical devices, tissue adhesives, and wound dressings.
    Matched MeSH terms: Tissue Adhesives/chemistry*
  9. Fulltext Pre-clinical evaluation of novel mucoadhesive bilayer patches for local delivery of clobetasol-17-propionate to the oral mucosa
    Colley HE, Said Z, Santocildes-Romero ME, Baker SR, D'Apice K, Hansen J, et al.
    Biomaterials, 2018 09;178:134-146.
    PMID: 29929183 DOI: 10.1016/j.biomaterials.2018.06.009
    Oral lichen planus (OLP) and recurrent aphthous stomatitis (RAS) are chronic inflammatory conditions often characterised by erosive and/or painful oral lesions that have a considerable impact on quality of life. Current treatment often necessitates the use of steroids in the form of mouthwashes, creams or ointments, but these are often ineffective due to inadequate drug contact times with the lesion. Here we evaluate the performance of novel mucoadhesive patches for targeted drug delivery. Electrospun polymeric mucoadhesive patches were produced and characterised for their physical properties and cytotoxicity before evaluation of residence time and acceptability in a human feasibility study. Clobetasol-17-propionate incorporated into the patches was released in a sustained manner in both tissue-engineered oral mucosa and ex vivo porcine mucosa. Clobetasol-17 propionate-loaded patches were further evaluated for residence time and drug release in an in vivo animal model and demonstrated prolonged adhesion and drug release at therapeutic-relevant doses and time points. These data show that electrospun patches are adherent to mucosal tissue without causing tissue damage, and can be successfully loaded with and release clinically active drugs. These patches hold great promise for the treatment of oral conditions such as OLP and RAS, and potentially many other oral lesions.
    Matched MeSH terms: Adhesives/pharmacology*
  10. Development of a bioactive dentin adhesive resin modified with magnesium-doped synthetic hydroxyapatite crystals
    Daood U, Fawzy A
    J Mech Behav Biomed Mater, 2023 Apr;140:105737.
    PMID: 36827934 DOI: 10.1016/j.jmbbm.2023.105737
    The aim is to evaluate the development of an experimental multi-mode/Universal resin-based dentin adhesive modified with synthetic Mg2+ doped hydroxyapatite crystals (HAp) having self-remineralization and antibiofilm properties. HAp doped with Mg2+ was prepared by the precipitation method. Experimental adhesives were subjected to degree of conversion and X-ray diffraction test for size and crystal structure. Bond strength was tested, and electron microscopy (SEM/TEM) imaging of resin-dentin interface was done along with nanoleakage, nanoindentation, confocal and Raman analyses. S. mutans was analysed using CLSM images against modified adhesive specimens. Nucleating abilities within the resin-dentin specimens are determined by measuring Ca2+. Alkaline phosphatase, Runx2, and Ocn transcripts are amplified using quantitative polymerase chain reaction (q-PCR). A calcium assay is performed to quantify level of mineralisation. When compared to control adhesives, the 0.5% Hap/Mg2+ containing experimental dentin adhesive demonstrated improved interaction with dentin. The preservation of uniform intact hybrid layer with the absence of nanoleakage indicated dentin bond integrity with 0.5% HAP/Mg2+ modified adhesive. Self-remineralization and antibiofilm potentials are supported.
    Matched MeSH terms: Adhesives/analysis
  11. Fulltext First evidence for temporary and permanent adhesive systems in the stalked barnacle cyprid, Octolasmis angulata
    Yap FC, Wong WL, Maule AG, Brennan GP, Chong VC, Lim LH
    Sci Rep, 2017 Mar 22;7:44980.
    PMID: 28327603 DOI: 10.1038/srep44980
    Although there have been extensive studies on the larval adhesion of acorn barnacles over the past few decades, little is known about stalked barnacles. For the first time, we describe the larval adhesive systems in the stalked barnacle, Octolasmis angulata and the findings differ from previous reports of the temporary (antennulary) and cement glands in thoracican barnacles. We have found that the temporary adhesives of cyprid are produced by the clustered temporary adhesive glands located within the mantle, instead of the specialised hypodermal glands in the second antennular segment as reported in the acorn barnacles. The temporary adhesive secretory vesicles (TASV) are released from the gland cells into the antennule via the neck extensions of the glands, and surrounded with microtubules in the attachment disc. Cement glands undergo a morphological transition as the cyprid grows. Synthesis of the permanent adhesives only occurs during the early cyprid stage, and is terminated once the cement glands reach maximum size. Evidence of the epithelial invaginations on the cement glands supports the involvement of exocytosis in the secretion of the permanent adhesives. This study provides new insight into the larval adhesives system of thoracican barnacles.
    Matched MeSH terms: Adhesives/chemistry*
  12. Fulltext Properties and Characterization of New Approach Organic Nanoparticle-Based Biocomposite Board
    Ismail I, Arliyani, Jalil Z, Mursal, Olaiya NG, Abdullah CK, et al.
    Polymers (Basel), 2020 Sep 28;12(10).
    PMID: 32998404 DOI: 10.3390/polym12102236
    Conventionally, panel boards are produced with material flex or microparticle with P.U. or U.F. as adhesives. However, in this study, nanoparticle with epoxy resin as an adhesive was used to produce nanoboard. Coconut shell nanoparticle composite with epoxy resin as an adhesive was prepared using a compression molding technique. The coconut shell particles were originally 200 mesh size and then milled mechanically with a ball mill for the duration of 10, 20, 30, and 40 h (milling times) to produce nanoparticles. The composition ratio of the composite is 85 vol.% of coconut shell and 15 vol.% of epoxy resin. The formation of nanoparticles was observed with transmission electron microscopy (TEM). The mechanical, physical, and microstructure properties of the composite were examined with X-ray diffraction, scanning electron microscopy, atomic force microscopy, and universal testing machine. The results established that the properties of the composite (microstructures, mechanical, and physical) are influenced by the duration of milling of coconut shell particles. The modulus and flexural strength of the composite improved with an increase in the milling time. The density, thickness swelling, and porosity of the composite were also influenced by the milling times. The result suggested that the composite properties were influenced by the particle size of the coconut shell. The coconut shell nanoparticle composite can be used in the manufacturing of hybrid panels and board.
    Matched MeSH terms: Adhesives
  13. Fulltext The use of epoxidised natural rubber latex for developing coloured adhesives
    Rohani Abu Bakar, Asrul Mustafa
    Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2020;8(1):58-65.
    MyJurnal
    Adhesives serve many functions in daily life, starting from sticking envelopes to rejoining broken
    materials. Adhesives are usually developed for a specific purpose and the performances can vary
    according to their specific end-use. Most of the commercially available adhesives comprised nonrenewable or petroleum derived raw materials. Thus, in order to mitigate negative impact of using nonrenewable material as the raw material for adhesives, a new type of adhesive containing epoxidised
    natural rubber (NR) latex is developed. Epoxidised NR latex adhesive was initially prepared and pigment
    was subsequently added to produce desired colours of the adhesive. Hence, the newly developed adhesive
    can serve as adhesive and also as paint for art. The adhesives were characterised and the results indicated
    that they were free from heavy metal contents and volatile organic compounds (VOCs). The adhesives
    exhibited comparable odour concentration to commercial synthetic-based adhesive. In terms of toxicity
    level, the adhesive developed exhibited low acute oral toxicity. Peel adhesion test of A4 and drawing
    papers on stainless steel and glass substrates, opacity and glossiness were also investigated in the present
    study. This coloured adhesive is deemed to support the STEM (science, technology, engineering and
    mathematics) learning by indirectly imparting polymer science and technology in art education and
    further promotes creative learning among school children. The adhesive is also derived from renewable
    material rendering it more environmentally friendly.
    Matched MeSH terms: Adhesives
  14. Fulltext PENYEK: Automated brown planthopper detection from imperfect sticky pad images using deep convolutional neural network
    Nazri A, Mazlan N, Muharam F
    PLoS One, 2018;13(12):e0208501.
    PMID: 30571683 DOI: 10.1371/journal.pone.0208501
    Rice is a staple food in Asia and it contributes significantly to the Gross Domestic Product (GDP) of Malaysia and other developing countries. Brown Planthopper (BPH) causes high levels of economic loss in Malaysia. Identification of BPH presence and monitoring of its abundance has been conducted manually by experts and is time-consuming, fatiguing and tedious. Automated detection of BPH has been proposed by many studies to overcome human fallibility. However, all studies regarding automated recognition of BPH are investigated based on intact specimen although most of the specimens are imperfect, with missing parts have distorted shapes. The automated recognition of an imperfect insect image is more difficult than recognition of the intact specimen. This study proposes an automated, deep-learning-based detection pipeline, PENYEK, to identify BPH pest in images taken from a readily available sticky pad, constructed by clipping plastic sheets onto steel plates and spraying with glue. This study explores the effectiveness of a convolutional neural network (CNN) architecture, VGG16, in classifying insects as BPH or benign based on grayscale images constructed from Euclidean Distance Maps (EDM). The pipeline identified imperfect images of BPH with an accuracy of 95% using deep-learning's hyperparameters: softmax, a mini-batch of 30 and an initial learning rate of 0.0001.
    Matched MeSH terms: Adhesives
  15. Adhesion ability and cytotoxic evaluation of lactobacillus strains isolated from malaysian fermented fish (pekasam) on ht-29 and ccd-18co intestinal cells
    Ida Muryany, Ahmad Rohi Ghazali, Nor Fadilah Rajab, Hing HL, Ina-Salwany, Mohd Zamri Saad, et al.
    Sains Malaysiana, 2018;47:2391-2399.
    Bacterial adhesion to host cells is the most important probiotic character. However, the adhesion of probiotic should not
    affect the viability of the host cells. In this study, Lactobacillus plantarum strain L8, Lactobacillus plantarum strain L20
    and Lactobacillus pentosus strain S1 were tested for their cytotoxic effects through MTT assay and their ability to adhere
    and colonize on HT-29 and CCD-18Co intestinal cells as detected microscopically using light microscopy and Scanning
    Electron Microscopy (SEM). No cytotoxicity effects were observed on both intestinal cells following 24 h treatment with
    all Lactobacillus strains. Additionally, all strains demonstrated strong adhesive activity where more than 100 bacteria
    adhered to both intestinal cells although differences in the adhesion scores observed among different strains. The adhesion
    as observed via SEM showed an autoagreggative pattern and adhered as clusters on the surface of both intestinal cells.
    In conclusion, all three Lactobacillus strains are non-cytotoxic to both cells with strong adhesion ability on intestinal
    cells and this study also proved that Malaysian fermented fish are good source of probiotic bacteria.
    Matched MeSH terms: Adhesives
  16. Profiling of cured residue of solvent-based adhesives by attenuated total reflectance-Fourier transform infrared spectroscopy with chemometrics for forensic investigation
    Saman SA, Chang KH, Abdullah AFL
    J Forensic Sci, 2021 Mar;66(2):608-618.
    PMID: 33202056 DOI: 10.1111/1556-4029.14625
    Abuse of solvent-based adhesives jeopardizes world population, especially the young generation. Adhesive-related exhibits encountered in forensic cases might need to be determined if they could have come from a particular source or to establish link between cases or persons. This study was aimed to discriminate solvent-based adhesives, especially to aid forensic investigation of glue sniffing activities. In this study, thirteen brands with three samples each, totaling at 39 adhesive samples, were analyzed using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy followed by chemometric methods. Experimental output showed that adhesive samples utilized in this study were less likely to change in their ATR-FTIR profiles over time, at least up to 2 months. No interference from plastic materials was noticed based on ATR-FTIR profile comparison. Physical examination could differentiate the samples into two groups, namely contact adhesives and cement adhesives. A principal component analysis-score linear discriminative analysis (PC-score LDA) model resulted in 100% and 98.6% correct classification in discriminating the two groups of adhesive samples, forming seven discriminative clusters. Test set with adhesive samples applied glass slide and plastic substrates also demonstrated a 100% correct classification into their respective groups. As a conclusion, the method allowed for discrimination of adhesive samples based on the spectral features, displaying relationship among samples. It is hoped that this comparative information is beneficial to trace the possible source of solvent-based adhesives, whenever they are recovered from a crime scene, for forensic investigation.
    Matched MeSH terms: Adhesives
  17. Characterization of soy-lignin bonded Rhizophora spp. particleboard as substitute phantom material for radiation dosimetric studies - Investigation of CT number, mass attenuation coefficient and effective atomic number
    Zuber SH, Hashikin NAA, Mohd Yusof MF, Aziz MZA, Hashim R
    Appl Radiat Isot, 2021 Apr;170:109601.
    PMID: 33515930 DOI: 10.1016/j.apradiso.2021.109601
    Experimental particleboards are made from Rhizophora spp. wood trunk with three different percentages of lignin and soy flour (0%, 6% and 12%) as adhesives. The objective was to investigate the equivalence of Rhizophora spp. particleboard as phantom material with human soft tissue using Computed Tomography (CT) number. The linear and mass attenuation coefficient of Rhizophora spp. particleboard at low energy range was also explored using X-ray Fluorescence (XRF) configuration technique. Further characterization of the particleboard was performed to determine the effective atomic number, Zeff using Energy Dispersive X-Ray (EDX) method. Adhesive-bonded Rhizophora spp. particleboard showed close similarities with water, based on the average CT numbers, electron density calibration curve and the analysis of CT density profile, compared to the binderless particleboard. The effective atomic number obtained from the study indicated that the attenuation properties of all the particleboards at different percentages of adhesives were almost similar to water. The mass attenuation coefficient calculated from XRF configuration technique showed good agreement with water from XCOM database, suggesting its potential as phantom material for radiation study.
    Matched MeSH terms: Adhesives
  18. Fulltext Inhibition of matrix metalloproteinases: a troubleshooting for dentin adhesion
    de Moraes IQS, do Nascimento TG, da Silva AT, de Lira LMSS, Parolia A, Porto ICCM
    Restor Dent Endod, 2020 Aug;45(3):e31.
    PMID: 32839712 DOI: 10.5395/rde.2020.45.e31
    Matrix metalloproteinases (MMPs) are enzymes that can degrade collagen in hybrid layer and reduce the longevity of adhesive restorations. As scientific understanding of the MMPs has advanced, useful strategies focusing on preventing these enzymes' actions by MMP inhibitors have quickly developed in many medical fields. However, in restorative dentistry, it is still not well established. This paper is an overview of the strategies to inhibit MMPs that can achieve a long-lasting material-tooth adhesion. Literature search was performed comprehensively using the electronic databases: PubMed, ScienceDirect and Scopus including articles from May 2007 to December 2019 and the main search terms were "matrix metalloproteinases", "collagen", and "dentin" and "hybrid layer". MMPs typical structure consists of several distinct domains. MMP inhibitors can be divided into 2 main groups: synthetic (synthetic-peptides, non-peptide molecules and compounds, tetracyclines, metallic ions, and others) and natural bioactive inhibitors mainly flavonoids. Selective inhibitors of MMPs promise to be the future for specific targeting of preventing dentin proteolysis. The knowledge about MMPs functionality should be considered to synthesize drugs capable to efficiently and selectively block MMPs chemical routes targeting their inactivation in order to overcome the current limitations of the therapeutic use of MMPs inhibitors, i.e., easy clinical application and long-lasting effect.
    Matched MeSH terms: Adhesives
  19. Fulltext Evaluation of interface adhesion between silicone soft liners and denture base after immersion with denture cleansers by scanning electron microscope
    Aiemeeza Rajali, Siti Fauzza Ahmad
    Malaysian Journal of Medicine and Health Sciences, 2020;16(3):148-154.
    MyJurnal
    Introduction: The compatibility of denture cleanser is crucial in the prevention of failure of adhesion between silicone soft liner and acrylic denture base, thus ensuring the durability of the prosthesis. This scanning electron microscope (SEM) study was to determine the mode of failure and measured the gap formation between silicone soft liners and Polymethylmethacrylate (PMMA) denture base after immersion in denture cleansers. Methods: A total of 135 specimens of PMMA denture base lined with three different silicone soft liners (GC Reline Soft, Mollosil and Tokuyama Sofreliner Tough) were immersed into denture cleansers (Polident® and Stearadent) daily and stored in distilled water at 37±1°C. Specimens were examined and sectioned at 2.5mm and 5.0mm from the margin after 1 day, 30 days and 90 days before analyzed. Results: No significant difference detected in the mode of failure and gap formation after one-day immersion. Adhesive failure was the commonest failure at the margin after 30 days (71.11%) and after 90 days (95.56%). However, 33.33% of specimens showed mixed failure at 5.0mm sectioned after 90 days. A significant difference of gap formation was demonstrated from Mollosil in Steradent at the margin and at 2.5 mm sectioned after 30 days and after 90 days (p
    Matched MeSH terms: Adhesives
  20. Multiscale in-vitro analysis of photo-activated riboflavin incorporated in an experimental universal adhesive
    Fu C, Deng S, Koneski I, Awad MM, Akram Z, Matinlinna J, et al.
    J Mech Behav Biomed Mater, 2020 12;112:104082.
    PMID: 32979607 DOI: 10.1016/j.jmbbm.2020.104082
    OBJECTIVE: To investigate the effect of blue light photoactivated riboflavin modified universal adhesives on dentin collagen biodegradation resistance, dentin apparent elastic modulus, and resin-dentin bond strength with interfacial morphology.

    METHODS: Dentin slabs were treated with 0.1% riboflavin-5-phosphate modified (powder added slowly while shaking and then sonicated to enhance the dispersion process) Universal Adhesive Scotch Bond and Zipbond™ along with control (non-modified) and experimental adhesives, photoactivated with blue light for 20s. Hydroxyproline (HYP) release was assessed after 1-week storage. Elastic-modulus testing was evaluated using universal testing machine at 24 h. Resin-dentin interfacial morphology was assessed with scanning electron-microscope, after 6-month storage. 0.1% rhodamine dye was added into each adhesive and analyzed using CLSM. Detection of free amino groups was carried out using ninhydrin and considered directly proportional to optical absorbance. Collagen molecular confirmation was determined using spectropolarimeter to evaluate and assess CD spectra. For molecular docking studies with riboflavin (PDB ID file), the binding pocket was selected with larger SiteScore and DScore using Schrodinger PB software. After curing, Raman shifts in Amide regions were obtained at 8 μm levels. Data were analyzed using Two-way analysis of variance (ANOVA, p ≤ 0.05) and Tukey-Kramer multiple comparison post hoc tests.

    RESULTS: At baseline, bond strength reduced significantly (p ≤ 0.05) in control specimens. However, at 6 months' storage, UVA Zipbond™ had significantly higher μTBS. Resin was able to diffuse through the porous demineralized dentin creating adequate hybrid layers in both 0.1%RF modified adhesives in CLSM images. In riboflavin groups, hybrid layer and resin tags were more pronounced. The circular dichroism spectrum showed negative peaks for riboflavin adhesive specimens. Best fitted poses adopted by riboflavin compound are docked with MMP-2 and -9 proteases. Amide bands and CH2 peaks followed the trend of being lowest for control UA Scotch bond adhesive specimens and increasing in Amides, proline, and CH2 intensities in 0.1%RF modified adhesive specimens. All 0.1%RF application groups showed statistically significant (p 

    Matched MeSH terms: Adhesives
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