scholarly journals The Effect of Thermocycling on Interfacial Bonding Stability of Self-Etch Adhesives: OCT Study

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
T. A. Bakhsh ◽  
A. Turkistani
Keyword(s):  
Laser Scanning ◽  
Adhesive System ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Gap Formation ◽  
Swept Source ◽  
Before And After ◽  
One Step ◽  
Self Etch ◽  
Filled Composite

Objective. The aim of this study was to monitor the behavior of interfacial gaps formed under different bonded polymeric restorations before and after thermocycling (TC), using swept-source optical coherence tomography (SS-OCT) and confirming the obtained findings with confocal laser scanning microscopy (CLSM). Materials and Methods. Cylindrical class I cavities were prepared in twenty noncarious human premolar teeth ( 1.5   mm   depth × 3.5   mm   diameter ) and divided randomly into two groups: TS and SN, according to the adhesive system ( n = 10 ). In the TS group, one-step self-etch adhesive Clearfil Tri-S Bond Plus (Kuraray Noritake Dental, Japan) was used, followed by composite restoration using Estelite Sigma Quick (Tokuyama Dental, Japan). In the SN group, the cavities were restored with the two-step self-etch/composite silorane-based resin restoration system (3M ESPE, USA). All specimens were restored in bulk filling technique and cured in accordance with the manufacturers’ instructions. Both groups were imaged under SS-OCT after 24 h and recorded as controls. Then, each group was subjected to thermal challenge using the TC machine (5–55°C) and B-scans were recorded at different TC intervals (2600, 5200, and 10000). In order to confirm the SS-OCT findings, additional specimens were prepared, scanned, and sectioned for CLSM observation. Results. B-scans demonstrated white clusters at the tooth-resin interface that corresponded to the gap location on CLSM images. The TS group showed significantly less gap formation than the SN group before and after TC ( p < 0.001 ). Conclusions. An optimal composite adaptation can be achieved when the bonded restoration comprises a combination of an adhesive containing 10-MDP monomer and a considerable highly filled composite.

Triacrylamide-Based Adhesives Stabilize Bonds in Physiologic Conditions

2022 ◽  
pp. 002203452110617
Author(s):  
F.S. de Lucena ◽  
S.H. Lewis ◽  
A.P.P. Fugolin ◽  
A.Y. Furuse ◽  
J.L. Ferracane ◽  
...  
Keyword(s):  
Bond Strength ◽  
Cross Sections ◽  
Laser Scanning ◽  
Adhesive System ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Gap Formation ◽  
Bond Stability ◽  
Occlusal Surfaces ◽  
Before And After

In this study, an acrylamide-based adhesive was combined with a thiourethane-based composite to improve bond stability and reduce polymerization stress, respectively, of simulated composite restorations. The stability testing was conducted under physiologic conditions, combining mechanical and bacterial challenges. Urethane dimethacrylate was combined with a newly synthesized triacrylamide (TMAAEA) or HEMA (2-hydroxyethyl-methacrylate; control) to produce a 2-step total-etch adhesive system. Methacrylate-based composites (70 wt% silanized filler) were formulated, containing thiourethane oligomers at 0 (control) or 20 wt%. Standardized preparations in human third molars were restored; then, epoxy replicas were obtained from the occlusal surfaces before and after 7-d storage in water or with Streptococcus mutans biofilm, which was tested after storage in an incubator (static) or the bioreactor (mechanical challenge). Images were obtained from the replicas (scanning electron microscopy) and cross sections of the samples (confocal laser scanning microscopy) and then analyzed to obtain measurements of gap, bacterial infiltration, and demineralization. Microtensile bond strength of specimens stored in water or biofilm was assessed in 1-mm2 stick specimens. Data were analyzed with analysis of variance and Tukey’s test (α = 0.05). HEMA-based materials had greater initial gap measurements, indicating more efficient bonding for the acrylamide materials. When tested in water, the triacrylamide-based adhesive had smaller gaps in the incubator or bioreactor. In the presence of biofilm, there was less difference among materials, but the acrylamide/thiourethane combination led to statistically lower gap formation in the bioreactor. HEMA and TMAAEA-based adhesives produced statistically similar microtensile bond strengths after being stored in water for 7 d, but after the same period with biofilm-challenged specimens, the TMAAEA-based adhesives were the only ones to retain the initial bond strength values. The use of a stable multiacrylamide-based adhesive led to the preservation of the resin-dentin bonded interface after a physiologically relevant challenge. Future studies will include a multispecies biofilm model.

scholarly journals One-step preparation of antimicrobial silicone materials based on PDMS and salicylic acid: insights from spatially and temporally resolved techniques

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Luca Barbieri ◽  
Ioritz Sorzabal Bellido ◽  
Alison J. Beckett ◽  
Ian A. Prior ◽  
Jo Fothergill ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Laser Scanning ◽  
Pathogenic Bacteria ◽  
Pharmaceutical Products ◽  
Laser Scanning Microscopy ◽  
Wound Dressings ◽  
Confocal Laser ◽  
Vis Spectroscopy ◽  
Wide Range ◽  
One Step

AbstractIn this work, we introduce a one-step strategy that is suitable for continuous flow manufacturing of antimicrobial PDMS materials. The process is based on the intrinsic capacity of PDMS to react to certain organic solvents, which enables the incorporation of antimicrobial actives such as salicylic acid (SA), which has been approved for use in humans within pharmaceutical products. By combining different spectroscopic and imaging techniques, we show that the surface properties of PDMS remain unaffected while high doses of the SA are loaded inside the PDMS matrix. The SA can be subsequently released under physiological conditions, delivering a strong antibacterial activity. Furthermore, encapsulation of SA inside the PDMS matrix ensured a diffusion-controlled release that was tracked by spatially resolved Raman spectroscopy, Attenuated Total Reflectance IR (ATR-IR), and UV-Vis spectroscopy. The biological activity of the new material was evaluated directly at the surface and in the planktonic state against model pathogenic bacteria, combining confocal laser scanning microscopy, electron microscopy, and cell viability assays. The results showed complete planktonic inhibition for clinically relevant strains of Staphylococcus aureus and Escherichia coli, and a reduction of up to 4 orders of magnitude for viable sessile cells, demonstrating the efficacy of these surfaces in preventing the initial stages of biofilm formation. Our approach adds a new option to existing strategies for the antimicrobial functionalisation of a wide range of products such as catheters, wound dressings and in-dwelling medical devices based on PDMS.

scholarly journals Enhanced Grain-boundary Emission Lifetime and Additive Induced Crystal Orientation in One-Step Spin-Coated Mixed Cationic (FA/MA) Lead Perovskite Thin Films Stabilized by Zinc Iodide Doping

2017 ◽  
Author(s):  
René M. Williams ◽  
Loreta A. Muscarella ◽  
Dina Petrova ◽  
Rebecca Jorge Cervasio ◽  
Aram Farawar ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Crystal Formation ◽  
Ambient Conditions ◽  
Emission Lifetime ◽  
Photoluminescence Lifetime ◽  
One Step ◽  
Zinc Iodide

Mixed cationic lead perovskites containing formamidinium and methylammonium can be stabilized by incorporating ZnI<sub>2 </sub>as an “internal desiccant”. Next to prolonged stability under ambient conditions we show with XRD that the use of an additive, 3-chloropropyl ammonium chloride, influences crystal formation by orienting the crystals. These ~500 nm crystals show individual photoluminescent behavior in thin films and have a longer photoluminescence lifetime at the grain boundaries as compared to the center of the crystal or relative to un-doped materials without the additive made under identical conditions. Charges recombine slower at the edges of the crystals as observed with confocal laser scanning microscopy

Effect of Calcium-phosphate Desensitizers on Staining Susceptibility of Acid-eroded Enamel

2019 ◽  
Vol 44 (3) ◽  
pp. 281-288 ◽  
Author(s):  
KY Kyaw ◽  
M Otsuki ◽  
MS Segarra ◽  
N Hiraishi ◽  
J Tagami
Keyword(s):  
Surface Roughness ◽  
Calcium Phosphate ◽  
Repeated Measures ◽  
Laser Scanning ◽  
Artificial Saliva ◽  
Color Difference ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Control Group ◽  
Before And After

SUMMARY Objective: To investigate the effect of calcium-phosphate–based desensitizers, Teethmate AP paste (TMAP) and Teethmate Desensitizer (TMD) (Kuraray Noritake Dental, Tokyo, Japan), on the prevention of staining on acid-eroded enamel. Methods and Materials: Forty polished enamel samples (4×4×1 mm) from bovine incisors were randomly divided into five groups (n=8). After immersion in 50 mL of 0.5% citric acid (pH 2.5) for 15 minutes to form acid-eroded surfaces, the surfaces were subjected to different treatments with TMAP, TMD, and NaF (0.21% means 950 ppm) for five minutes. Another eroded group was not treated with desensitizer. For the control group, the samples were not eroded or treated. All the samples were stored in artificial saliva (AS) at pH 7.2 for 24 hours at 37°C. The TMAP, TMD, or NaF was reapplied at eight and 16 hours during the 24 hours of storage time. The surface roughness (Sa) was evaluated following ISO 25178 for surface texture using confocal laser scanning microscopy (VK-X 150 series, Keyence, Osaka, Japan) before acid erosion, after acid erosion, and after 24 hours of incubation in AS. Afterward, the color difference was measured with a dental colorimeter (Shade Eye NCC, Shofu, Kyoto, Japan) before and after staining with tea solution. Results: One-way repeated measures analysis of variance showed that acid erosion significantly increased Sa (p&lt;0.001). TMAP- and TMD-treated groups exhibited lower Sa values than the NaF group and the no-desensitizer treatment group. The greatest staining was observed in the NaF group and the no-desensitizer group, while the TMAP and TMD groups significantly decreased the formation of stains. Conclusions: Acid-eroded enamel increased surface roughness and tended to absorb more stains. However, the application of TMAP and TMD moderated the roughness and thus prevented the formation of extrinsic stains.

Control of Thermal-Oxidative Degradation of Natural Rubber STR 5L by Using Cysteine Encapsulated with Alginate/Chitosan Microcapsules

2014 ◽  
Vol 1044-1045 ◽  
pp. 743-749 ◽  
Author(s):  
Narumol Kreua-Ongarjnukool ◽  
Surakit Tuampoemsab ◽  
Pensiri Rattanasupa
Keyword(s):  
Natural Rubber ◽  
Laser Scanning ◽  
Average Molecular Weight ◽  
Oxidative Degradation ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Thermal Oxidative Degradation ◽  
Rubber Sample ◽  
Aging Test ◽  
Before And After

This research was to study the efficiency of cysteine (Cys) acted as a natural antioxidant, which was encapsulated in alginate/chitosan (AG/CS) microcapsules to control the thermal oxidative degradation of natural rubber STR 5L. The microcapsules were prepared by a combined method based on ionic gelation and electrospraying techniques. The preparation of AG/CS microcapsules were executed to find the appropriate parameters such as applying voltage and concentration of alginate and chitosan. The applied voltage achieved for controlling the particle size as well as narrow size distribution of microcapsule. The AG/CS/Cys microcapsules were found to be a spherical shape and the average size was approximately 120 μm. The percentage of cysteine encapsulated within AG/CS microcapsules was increased with the increasing of chitosan concentration and encapsulation efficiency of cysteine in the microcapsules is about 81%. Core-shell structure of the microcapsule was confirmed by confocal laser scanning microscopy. After that, the natural rubber STR 5L mixed with AG/CS/Cys microcapsules was evaluated the oxidative resistance by Wallace plasticity. Thermal aging test according to standard ASTM D1349 at 70°C of the STR 5L mixed with AG/CS/Cys microcapsules were carried out. Weight-average molecular weight (w) of the rubber sample before and after aging test was also investigated by gel permeation chromatography. Thewof rubber sample before and after aging test presented clearly results depending on the aging time. Concisely, the AG/CS/Cys microcapsules have a potential to control release Cys and can be used to control the deterioration of raw STR 5L. The model of this encapsulation is expected to be applied with other applications.

scholarly journals Enhanced Grain-boundary Emission Lifetime and Additive Induced Crystal Orientation in One-Step Spin-Coated Mixed Cationic (FA/MA) Lead Perovskite Thin Films Stabilized by Zinc Iodide Doping

2017 ◽  
Author(s):  
Loreta A. Muscarella ◽  
Dina Petrova ◽  
Rebecca Jorge Cervasio ◽  
Aram Farawar ◽  
Olivier Lugier ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Crystal Formation ◽  
Ambient Conditions ◽  
Emission Lifetime ◽  
Photoluminescence Lifetime ◽  
One Step ◽  
Zinc Iodide

Mixed cationic lead perovskites containing formamidinium and methylammonium can be stabilized by incorporating ZnI<sub>2 </sub>as an “internal desiccant”. Next to prolonged stability under ambient conditions we show with XRD that the use of an additive, 3-chloropropyl ammonium chloride, influences crystal formation by orienting the crystals. These ~500 nm crystals show individual photoluminescent behavior in thin films and have a longer photoluminescence lifetime at the grain boundaries as compared to the center of the crystal or relative to un-doped materials without the additive made under identical conditions. Charges recombine slower at the edges of the crystals as observed with confocal laser scanning microscopy. The material can also be prepared as a black precursor powder by a solid-solid reaction under ambient conditions.

scholarly journals Enhanced Grain-boundary Emission Lifetime and Additive Induced Crystal Orientation in One-Step Spin-Coated Mixed Cationic (FA/MA) Lead Perovskite Thin Films Stabilized by Zinc Iodide Doping

2017 ◽  
Author(s):  
Loreta A. Muscarella ◽  
Dina Petrova ◽  
Rebecca Jorge Cervasio ◽  
Aram Farawar ◽  
Olivier Lugier ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Crystal Formation ◽  
Ambient Conditions ◽  
Emission Lifetime ◽  
Photoluminescence Lifetime ◽  
One Step ◽  
Zinc Iodide

Mixed cationic lead perovskites containing formamidinium and methylammonium can be stabilized by incorporating ZnI<sub>2 </sub>as an “internal desiccant”. Next to prolonged stability under ambient conditions we show with XRD that the use of an additive, 3-chloropropyl ammonium chloride, influences crystal formation by orienting the crystals. These ~500 nm crystals show individual photoluminescent behavior in thin films and have a longer photoluminescence lifetime at the grain boundaries as compared to the center of the crystal or relative to un-doped materials without the additive made under identical conditions. Charges recombine slower at the edges of the crystals as observed with confocal laser scanning microscopy. The material can also be prepared as a black precursor powder by a solid-solid reaction under ambient conditions.

scholarly journals Ferulated Pectins and Ferulated Arabinoxylans Mixed Gel for Saccharomyces boulardii Entrapment in Electrosprayed Microbeads

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2478
Author(s):  
Federico Ohlmaier-Delgadillo ◽  
Elizabeth Carvajal-Millan ◽  
Yolanda L. López-Franco ◽  
María A. Islas-Osuna ◽  
Valérie Micard ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Cell Immobilization ◽  
Value Added ◽  
Saccharomyces Boulardii ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Cross Linking ◽  
Low Degree ◽  
Before And After ◽  
Probiotic Yeast

Ferulated polysaccharides such as pectin and arabinoxylan form covalent gels which are attractive for drug delivery or cell immobilization. Saccharomyces boulardii is a probiotic yeast known for providing humans with health benefits; however, its application is limited by viability loss under environmental stress. In this study, ferulated pectin from sugar beet solid waste (SBWP) and ferulated arabinoxylan from maize bioethanol waste (AX) were used to form a covalent mixed gel, which was in turn used to entrap S. boulardii (2.08 × 108 cells/mL) in microbeads using electrospray. SBWP presented a low degree of esterification (30%), which allowed gelation through Ca2+, making it possible to reduce microbead aggregation and coalescence by curing the particles in a 2% CaCl2 cross-linking solution. SBWP/AX and SBWP/AX+ S. boulardii microbeads presented a diameter of 214 and 344 µm, respectively, and a covalent cross-linking content (dimers di-FA and trimer tri-FA of ferulic acid) of 1.15 mg/g polysaccharide. The 8-5′, 8-O-4′and 5-5′di-FA isomers proportions were 79%, 18%, and 3%, respectively. Confocal laser scanning microscopy images of propidium iodide-stained yeasts confirmed cell viability before and after microbeads preparation by electrospray. SBWP/AX capability to entrap S. boulardii would represent an alternative for probiotic immobilization in tailored biomaterials and an opportunity for sustainable waste upcycling to value-added products.

Sign in / Sign up

Export Citation Format

Share Document