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The Journal of Contemporary Dental... Dec 2023The aim of the current study was to evaluate the dimensional accuracy of three various interocclusal recording materials.
AIM
The aim of the current study was to evaluate the dimensional accuracy of three various interocclusal recording materials.
MATERIALS AND METHODS
A total of 90 disc-shaped samples were prepared using polyether paste, wax, and polyvinyl siloxane material with the support of stainless steel die. For the purposes of this investigation, three frequently utilized interocclusal recording materials were chosen, and 30 samples from each material were prepared. Group I: Bite registration using polyether paste; Group II: Bite registration using wax; Group III: Bite registration using polyvinyl siloxane material. No samples were exposed to direct sunlight during storage and were kept at room temperature. Using a 10x universal measuring microscope, each sample disc was examined for the presence of horizontal and vertical lines inscripted in the die. For each of the samples, readings were taken at different time periods of 24, 48, and 72 hours.
RESULTS
After 24 hours, the less dimensional changes were found in polyether paste group (0.11 ± 0.07) followed by polyvinyl siloxane material group (0.19 ± 0.04) and wax group (0.25 ± 0.12). After 48 hours, the less dimensional changes were found in polyether paste group (0.34 ± 0.02) followed by polyvinyl siloxane material group (0.42 ± 0.01) and wax group (0.94 ± 0.12). After 72 hours, the least dimensional changes were found in polyether paste group (0.46 ± 0.14) followed by polyvinyl siloxane material group (0.92 ± 0.03) and wax group (1.14 ± 0.09).
CONCLUSION
The present study concluded that both the material and time factors had an impact on dimensional stability. The most dimensionally stable group was the polyether paste group, which was followed by the polyvinyl siloxane and wax material groups.
CLINICAL SIGNIFICANCE
Interocclusal recording material records the occlusal connection between real or artificial teeth for occlusal rehabilitation planning and for creating removable and fixed dentures. The creation of a clinically acceptable prosthesis is dependent upon the accuracy of the patient's diagnostic or working casts and the interocclusal record. How to cite this article: Sonkesriya S, Subramanian D, Saha P, . Assessment of Dimensional Accuracy of Three Different Types of Interocclusal Recording Materials. J Contemp Dent Pract 2023;24(12):936-939.
Topics: Humans; Dental Impression Materials; Jaw Relation Record; Siloxanes; Polyvinyls
PubMed: 38317389
DOI: 10.5005/jp-journals-10024-3574 -
Korean Journal of Anesthesiology Aug 2023Direct insertion of a double-lumen tube (DLT) using a flexible fiberoptic bronchoscope (FOB) is an option for DLT intubation. The difficult process of fiberoptic...
BACKGROUND
Direct insertion of a double-lumen tube (DLT) using a flexible fiberoptic bronchoscope (FOB) is an option for DLT intubation. The difficult process of fiberoptic intubation is that the different properties of polyvinyl chloride and silicone DLTs may affect railroading differently. Therefore, we aimed to compare intubation using polyvinyl chloride and silicone DLTs over an FOB.
METHODS
Patients aged 19-75 years who required one-lung ventilation under general anesthesia were enrolled in this study. After induction of anesthesia, the anesthesiologist intubated the DLT using FOB. The primary outcome was the difficulty of railroading over the flexible FOB scaled into five grades (I, II-1, II-2, III, and IV). Additionally, the intubation time and mucosal damage were recorded.
RESULTS
A total of 46 patients participated in this study, 23 each in the silicone and polyvinyl groups. The difficulty of railroading over the FOB was significantly different between the two groups (P < 0.001). In the silicone group, the grades of difficulty in railroading were limited to I and II-1; 20 patients (87%) presented no difficulty in advancing the tube. In contrast, in the polyvinyl group, 13 patients (57%) had scores of II-2 and III. Both the intubation time and mucosal damage were significantly better in the silicone group than in the polyvinyl group.
CONCLUSIONS
Intubation using a silicone DLT over an FOB was easier and faster than that with a polyvinyl chloride DLT with lesser trauma around the glottis.
Topics: Humans; Bronchoscopes; Polyvinyl Chloride; Intubation, Intratracheal; Polyvinyls; Silicones; Anesthesia, General
PubMed: 36577506
DOI: 10.4097/kja.22649 -
Journal of the Mechanical Behavior of... Dec 2023The polymeric nanofiber may interact and control certain regeneration processes at the molecular level to repair damaged tissues. This research focuses on the...
The polymeric nanofiber may interact and control certain regeneration processes at the molecular level to repair damaged tissues. This research focuses on the development of characterization and antibacterial capabilities of polyvinyl alcohol (PVA)/chitosan (CS) nanofibres containing fucoidan (FUC) for tissue engineering as a skin tissue substitute. A control group consisting of 13% PVA/(0.1)% CS nanofiber was prepared. To confer antibacterial properties to the nanofiber, 10, 20, and 30 mg of FUC were incorporated into this control group. The scanning electron microscope (SEM) proved the homogeneous and beadless structures of the nanofibers. The antibacterial activity of the 13% PVA/(0.1)% CS/(10, 20, 30) FUC was tested against the S.aureus and E.coli and the results showed that with FUC addition, the antibacterial activities of the nanofibers increased. The biocompatibility test was performed with a fibroblast cell line for 1, 3, and 7 days of incubation and the results demonstrated that FUC addition enhanced the bioactivity of the 13% PVA/(0.1)% CS nanofibers. In addition, the biocompatibility results showed that 13% PVA/(0.1)% CS/10 FUC had the highest viability value for all incubation periods compared to the others. In addition, the tensile test results showed that; the maximum tensile strength value was observed for 13% PVA/(0.1)% CS/10 FUC nanofibers.
Topics: Chitosan; Polyvinyl Alcohol; Nanofibers; Polyvinyls; Tissue Engineering; Anti-Bacterial Agents; Staphylococcus aureus; Escherichia coli
PubMed: 37832172
DOI: 10.1016/j.jmbbm.2023.106163 -
Microbial Ecology Oct 2023Chironomus riparius are sediment-dwelling invertebrates in freshwater ecosystems and are used as indicators of environmental pollution. Their habitat is threatened by...
Chironomus riparius are sediment-dwelling invertebrates in freshwater ecosystems and are used as indicators of environmental pollution. Their habitat is threatened by high levels of contaminants such as microplastics and organic matter. A promising strategy for the eco-friendly degradation of pollutants is the use of bacteria and their enzymatic activity. The aim of this study was to characterize for the first time bacteriobiota associated with the gut of C. riparius larvae from nature and laboratory samples, to compare it with sediment and food as potential sources of gut microbiota, and to assess its ability to degrade cellulose, proteins, and three different types of microplastics (polyethylene, polyvinyl chloride, and polyamide). The metabarcoding approach highlighted Proteobacteria, Firmicutes, Bacteroidota, and Actinobacteriota as most abundant in both gut samples. Culturable microbiota analysis revealed Metabacillus idriensis, Peribacillus simplex, Neobacillus cucumis, Bacillus thuringiensis/toyonensis, and Fictibacillus phosphorivorans as five common species for nature and laboratory samples. Two P. simplex and one P. frigoritolerans isolates showed the ability for intensive growth on polyethylene, polyvinyl chloride, and polyamide. Both cellulolytic and proteolytic activity was observed for Paenibacillus xylanexedens and P. amylolyticus isolates. The characterized strains are promising candidates for the development of environmentally friendly strategies to degrade organic pollution and microplastics in freshwater ecosystems.
Topics: Animals; Microplastics; Plastics; Nylons; Larva; Ecosystem; Chironomidae; Polyvinyl Chloride; Bacteria; Polyethylenes
PubMed: 36806012
DOI: 10.1007/s00248-023-02199-6 -
Environmental Technology Apr 2024Composite membranes were prepared from lignin alkali (LA), polyvinyl alcohol (PVA), and cellulose nanofibrils (CNF) using a simple, low-cost, and environmentally...
Composite membranes were prepared from lignin alkali (LA), polyvinyl alcohol (PVA), and cellulose nanofibrils (CNF) using a simple, low-cost, and environmentally friendly method. The deodorization performances and structures of these membranes were also characterized. The sample referred to as L3C3P5 prepared with a solution containing 35.7 wt% LA, 53.6 wt% PVA, and 10.7 wt% CNF showed the best deodorization properties, and the HS adsorption time reached 36 min. The adsorption performance was further improved by adding nano-CuO to the membrane, and the HS adsorption time of the doped membrane L3C3P5C4 reached 60 min. While the HS adsorption performance improved, structural analysis revealed that the addition of nano-CuO reduced the crystallinity in the membrane, caused the membrane to crack, and led to a decrease in the mechanical properties. The surface oxygens in the L3C3P5C4 membrane were primarily C-O bonds and lattice oxygens in CuO. After the HS adsorption reaction, the lattice oxygen disappeared, and CuS products appeared.
Topics: Lignin; Cellulose; Polyvinyl Alcohol; Adsorption
PubMed: 36647594
DOI: 10.1080/09593330.2023.2169638 -
Journal of Hazardous Materials Jul 2023Microplastics (MPs) contamination in soils seriously threatens agroecosystems globally. However, very few studies have been done on the effects of MPs on the soil...
Microplastics (MPs) contamination in soils seriously threatens agroecosystems globally. However, very few studies have been done on the effects of MPs on the soil nitrogen cycle and related functional microorganisms. To assess MP's impact on the soil nitrogen cycle and related functional bacteria, we carried out a one-month soil incubation experiment using typical acidic soil. The soil was amended with alfalfa meal and was spiked with 1% and 5% (mass percentage) of low-density polyethylene (LDPE) and polyvinyl chloride (PVC) MPs. Our results showed that both LDPE and PVC addition significantly increased soil nitrification rate and nitrate reductase activity, which could further promote soil denitrification. The relative abundance of diazotrophs, ammonium oxidizing, and denitrifying bacterial groups were significantly altered with MPs addition. Moreover, the MPs treatments greatly enhanced denitrifying bacteria richness. Redundancy analysis showed that nitrate reductase activity was the most significant factor affecting the soil functional bacterial community. Correlation analysis shows that Nitrosospira genus might be for the improvement of soil nitrification rate. Our results implied that MPs exposure could significantly affect the soil nitrogen cycling in farmland ecosystems by influencing essential nitrogen functional microorganisms and related enzymatic activities.
Topics: Nitrification; Polyethylene; Microplastics; Plastics; Polyvinyl Chloride; Ecosystem; Soil; Nitrogen; Bacteria; Nitrate Reductases; Soil Microbiology
PubMed: 37043864
DOI: 10.1016/j.jhazmat.2023.131391 -
International Journal of Biological... Jun 2023Conductive hydrogels have promising applications in flexible electronic devices and artificial intelligence, which have attracted much attention in recent years....
Conductive hydrogels have promising applications in flexible electronic devices and artificial intelligence, which have attracted much attention in recent years. However, most conductive hydrogels have no antimicrobial activity, inevitably leading to microbial infections during utilization. In this work, a series of antibacterial and conductive polyvinyl alcohol and sodium alginate (PVA-SA) hydrogels were successfully developed with the incorporation of S-nitroso-N-acetyl-penicillamine (SNAP) and MXene through a freeze-thaw approach. Due to the reversibility of hydrogen bonding and electrostatic interactions, the resulting hydrogels had excellent mechanical properties. Specifically, the presence of MXene readily interrupted the crosslinked hydrogel network, but the best stretching can reach up to >300 %. Moreover, the impregnation of SNAP achieved the release of nitric oxide (NO) over several days under physiological conditions. Due to the release of NO, these composited hydrogels demonstrated high antibacterial activities (> 99 %) against both Gram-positive and negative S. aureus and E. coli bacteria. Notably, the excellent conductivity of MXene endowed the hydrogel with a sensitive, fast, and stable strain-sensing ability, to accurately monitor and distinguish subtle physiological activities of the human body including finger bending and pulse beating. These novel composited hydrogels are likely to have potential as strain-sensing materials in the field of biomedical flexible electronics.
Topics: Humans; Artificial Intelligence; Escherichia coli; Nitric Oxide; Polyvinyl Alcohol; Staphylococcus aureus; Alginates; Anti-Bacterial Agents; Electric Conductivity; Hydrogels; S-Nitroso-N-Acetylpenicillamine
PubMed: 37094648
DOI: 10.1016/j.ijbiomac.2023.124564 -
International Journal of Pharmaceutics Jul 2023Propolis-loaded electrospun nanofibers (PENs) have been regarded as promising candidates for biomedical purposes such as wound healing/dressing owing to their...
Propolis-loaded electrospun nanofibers (PENs) have been regarded as promising candidates for biomedical purposes such as wound healing/dressing owing to their outstanding pharmacological and biological properties. This paper focuses on the development of electrospun nanofibers with optimum levels of propolis (PRP) and two polymer types (polycaprolactone (PCL) and polyvinyl alcohol (PVA)). Hence, response surface methodology (RSM) was employed to investigate the variation of the scaffold characteristics including porosity, average diameter, wettability, release, and tensile strength. For each response, a second-order polynomial model with a high coefficient of determination (R) values ranging from 0.95 to 0.989 was developed using multiple linear regression analysis. The overall optimum region with the best characteristics was found to be at PCL/6 % PRP and PVA/5 % PRP. After selecting the optimal samples, the cytotoxicity assay showed no toxicity for the optimal concentrations of PRP. Furthermore, Fourier transform infrared (FTIR) spectra revealed that no new chemical functional groups were introduced in the PENs. Uniform fibers were found in the optimum samples without the appearance of a bead-like structure in the fibers. In conclusion, nanofibers containing the optimal concentration of PRP with suitable properties can be used in biomedical and tissue engineering.
Topics: Polyvinyl Alcohol; Propolis; Nanofibers; Tissue Scaffolds; Polyesters
PubMed: 37385356
DOI: 10.1016/j.ijpharm.2023.123186 -
International Journal of Biological... Apr 2024Electrospinning has been acknowledged as an efficient technique for the fabrication of continuous nanofibers from polymeric based materials such as polyvinyl alcohol... (Review)
Review
Electrospinning has been acknowledged as an efficient technique for the fabrication of continuous nanofibers from polymeric based materials such as polyvinyl alcohol (PVA), cellulose acetate (CA), chitin nanocrystals and others. These nanofibers exhibit chemical and mechanical stability, high porosity, functionality, high surface area and one-dimensional orientation which make it extremely beneficial in industrial application. In recent years, research on chitin - a biopolymer derived from crustacean and fungal cell wall - had gained interest due to its unique structural arrangement, excellent physical and chemical properties, in which make it biodegradable, non-toxic and biocompatible. Chitin has been widely utilized in various applications such as wound dressings, drug delivery, tissue engineering, membranes, food packaging and others. However, chitin is insoluble in most solvents due to its highly crystalline structure. An appropriate solvent system is required for dissolving chitin to maximize its application and produce a fine and smooth electrospun nanofiber. This review focuses on the preparation of chitin polymer solution through dissolution process using different types of solvent system for electrospinning process. The effect of processing parameters also discussed by highlighting some representative examples. Finally, the perspectives are presented regarding the current application of electrospun chitin nanofibers in selected fields.
Topics: Chitin; Tissue Engineering; Polymers; Polyvinyl Alcohol; Solvents
PubMed: 38490398
DOI: 10.1016/j.ijbiomac.2024.130858 -
Carbohydrate Polymers Nov 2023Accurate and controlled release of drug molecules is crucial for transdermal drug delivery. Electricity, as an adjustable parameter, offers the potential for precise and...
Accurate and controlled release of drug molecules is crucial for transdermal drug delivery. Electricity, as an adjustable parameter, offers the potential for precise and controllable drug delivery. However, challenges exist in selecting the appropriate drug carrier, electrical parameters, and release model to achieve controlled electronic drug release. To overcome these challenges, this study designed a functional hydrogel using polyvinyl alcohol, chitosan, and graphene oxide as components that can conduct electricity, and constructed a drug transdermal release model using fluorescein sodium salt with proper electrical parameters. The results demonstrated that the hydrogel system exhibited low cytotoxicity, good conductivity, and desirable drug delivery characteristics. The study also integrated the effects of drug release and tissue repair promotion under electrical stimulation. Cell growth was enhanced under low voltage direct current pulses, promoting cell migration and the release of VEGF and FGF. Furthermore, the permeability of fluorescein sodium salt in the hydrogel increased with direct current stimulation. These findings suggest that the carbohydrate polymers hydrogel could serve as a drug carrier for controlled release, and electrical stimulation offers new possibilities for functional drug delivery and transdermal therapy.
Topics: Hydrogels; Polyvinyl Alcohol; Graphite; Chitosan; Delayed-Action Preparations; Fluorescein; Polyvinyls; Drug Delivery Systems; Electricity; Drug Carriers; Oxides
PubMed: 37567713
DOI: 10.1016/j.carbpol.2023.121172