scholarly journals The force effects of two types of polyethylene terephthalate glyc-olmodified clear aligners immersed in artificial saliva

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Biao Xiang ◽  
Xingxing Wang ◽  
Gang Wu ◽  
Yichen Xu ◽  
Menghan Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polyethylene Terephthalate ◽  
Artificial Saliva ◽  
Orthodontic Force ◽  
The Mean ◽  
The Stability ◽  
Scanning Electron

AbstractNumerous factors can influence the force exerted by clear aligners on teeth. This study aimed to investigate the stability of the force delivered by two different material appliances. 90 clear aligners with 2 materials and three different activations were designed and fabricated. Then, a device was employed to measure the force generated by the two types of PET-G material appliances immersed in artificial saliva for 0, 3, 7, 10, 14 days. Scanning electron microscopy was applied to observe the morphologic alterations on the aligner surfaces, respectively. The forces generated by different activation appliance exhibited differently, 0.0 mm < 0.1 mm < 0.2 mm. In addition, increasing the immersion times and the orthodontic force also decreased, but the forces decreased differently. Compared with the forces of conventional PETG appliances with 0.20 mm activation, the modified PETG appliances with the same activation exhibited significantly higher mean force. When comparing the mean force for modified PETG appliances after 10 and 14 days with conventional PETG appliances, the delivery forces exhibited significant differences (P < 0.05). The force delivered by both materials decreased obviously following artificial saliva immersion, and the force generated by modified aligners exhibited better stability than conventional aligners.

scholarly journals The Force Effects of Two Types of Polyethylene Terephthalate Glyc-olmodified Clear Aligners Immersed in Artificial Saliva

2020 ◽  
Author(s):  
Biao Xiang ◽  
Xingxing Wang ◽  
Gang Wu ◽  
Yichen Xu ◽  
Menghan Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polyethylene Terephthalate ◽  
Artificial Saliva ◽  
Orthodontic Force ◽  
The Mean ◽  
The Stability ◽  
Scanning Electron

Abstract Numerous factors can influence the force exerted by clear aligners teeth. This study aimed to investigate the stability of the force delivered by two different material appliances. 90 clear aligners with 2 materials and three different activations were designed and fabricated. Then, a device was employed to measure the force generated by the two types of PET-G material appliances immersed in artificial saliva for 0, 3, 7, 10, 14 days. Scanning electron microscopy was applied to observe the morphologic alterations on the aligner surfaces, respectively. The forces generated by different activation appliance exhibited differently, 0.0 mm < 0.1 mm < 0.2 mm. In addition, increasing the immersion times and the orthodontic force also decreased , but the forces decreased differently. Compared with the forces of conventional PETG appliances with 0.20 mm activation, the modified PETG appliances with the same activation exhibited significantly higher mean force. When comparing the mean force for modified PETG appliances after 10 and 14 days with conventional PETG appliances, the delivery forces exhibited significant differences (P<0.05). The force delivered by both materials decreased obviously following artificial saliva immersion, and the force generated by modified aligners exhibited better stability than conventional aligners.

Characteristics and Release Behavior of Sodium Alginate Microencapsulation Containing Cinnamon Oil

2010 ◽  
Vol 152-153 ◽  
pp. 508-511 ◽  
Author(s):  
Xi Hong Li ◽  
Juan Yun ◽  
Ya Ge Xing ◽  
Chang Liu ◽  
Qing Lian Xu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Relative Humidity ◽  
Core Material ◽  
Release Behavior ◽  
Cinnamon Oil ◽  
Mean Diameter ◽  
The Mean ◽  
The Stability ◽  
Scanning Electron

Microencapsulation technology is widely used in many industries recently because the stability of core material can be improved and the release characteristics can be modified. In this investigation, cinnamon oil was microencapsulated by simple coacervation. The size distribution is narrow and the mean diameter is 53.79 μm. The surface morphology of the resultant microcapsules was also characterized scanning electron microscopy (SEM). The results showed that the rates of cinnamon oil released from microencapsulation were not only affected by relative humidity in the microenvironment around microencapsulated powder, but also affected by the temperature.

A new species of Cribraria (Myxomycetes) from Australia

2018 ◽  
Vol 52 (2) ◽  
pp. 379-385 ◽  
Author(s):  
S. L. Stephenson ◽  
Yu. K. Novozhilov ◽  
P. Wellman
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Lemon Yellow ◽  
Moist Chamber ◽  
Light Yellow ◽  
Dark Violet ◽  
The Stability ◽  
A New Species ◽  
Scanning Electron

A new species of Cribraria, described herein as C. bicolor, appeared in moist chamber cultures on samples of the bark of Eucalyptus sp. collected at two localities in Australia. The morphology of representative specimens was examined by light and scanning electron microscopy, and micrographs of relevant morphological details of sporocarps and spores are provided. The species has a number of distinct and unique morphological features, including a glossy bright-violet globose sporotheca and a two-colored long stalk which is bright-red over the lower one-third and light yellow or lemon-yellow over the upper two-thirds. The combination of these characteristics as well as a shallow calyculus which is dark-violet when viewed under a dissecting microscope and bright red in transmitted light when mounted in lactophenol makes C. bicolor a well-defined morphospecies when compared to all other species of Cribraria. The stability of the taxonomic characters of the species was confirmed by an examination of a number of specimens.

Human Dentine Remineralization Under Non-colagen Materials Action

2017 ◽  
Vol 68 (5) ◽  
pp. 928-932
Author(s):  
Agripina Zaharia ◽  
Viorica Ghisman Plescan ◽  
Elena Maria Anghel ◽  
Viorica Musat
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Artificial Saliva ◽  
Composite Layer ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Agarose Hydrogel ◽  
Human Dentine ◽  
Dentine Surface ◽  
Scanning Electron

The purpose of this work is to induce biomimetic remineralization of acid etched coronal human dentine in artificial saliva (AS) under agarose (A) hydrogel or chitosan (CS)-A hydrogel action. The investigations focused on the morphology, chemical composition and crystalline structure of the new remineralized layers grown onto the etched dentinal surface (R) using scanning electron microscopy coupled with energy dispersive X-ray spectrometry and micro-Raman spectroscopy. Experimental results showed that remineralized layers grown in the presence of A or CS-A hydrogels consist in B-type Ca-deficient hydroxyapatite (HAP). After 7 days treatment into artificial saliva under agarose hydrogel, nanorod-like extrafibrilar HAP crystals randomly self-assembled in a discontinuous layer were formed, while in presence of chitosan-agarose hydrogel a continuous compact CS-HAP composite layer was obtained. The new biomimetic layer (A-CS4) formed after 4 days on dentine surface under A-CS hydrogel has higher crystallinity. Longer exposed (7 days) dentine in the presence of agarose hydrogel shows a higher mineral-to-collagen ratio (A7). Since dentine mineralization increases, the collagen quality factor decreases in succession A-CS4]R]A7. Results show a benefic effect of chitosan on remineralization of etched dentine.

Identification of Nd163 phase in melt-textured NdBa2Cu3O7−δ bulk samples

2003 ◽  
Vol 18 (9) ◽  
pp. 2050-2054 ◽  
Author(s):  
Marcello Gombos ◽  
Vicente Gomis ◽  
Anna Esther Carrillo ◽  
Antonio Vecchione ◽  
Sandro Pace ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Room Temperature ◽  
Polarized Light ◽  
Energy Dispersive ◽  
X Ray ◽  
Spontaneous Formation ◽  
The Stability ◽  
Scanning Electron

In this work, we report on the observation of Nd1Ba6Cu3O10,5 (Nd163) phase of the NdBaCuO system in melt-textured Nd123 bulk samples grown from a mixture of Nd123 and Nd210 phase powders. The observation was performed with polarized light optical microscopy and scanning electron microscopy–energy dispersive x-ray analyses. Images of the identified phase crystals show an aspect quite different from Nd422 crystals. Unexpectedly, Nd163 was individuated, even in “pure” Nd123 samples. Moreover, after long exposure to air, Nd163 disappeared completely in samples synthesized from powders containing Nd210. Thermogravimetry analyses of powders show that the stability of this phase in air is limited to temperatures higher than 900 °C, so Nd163 is unstable and highly reactive at room temperature. Moreover, an explanation of the observation of Nd163 in Nd210 free samples, based on the spontaneous formation of Nd163 phase in a Nd123 melt, is proposed.

Study on the Calamine/Sodium Alginate Modified Viscose Fiber

2011 ◽  
Vol 418-420 ◽  
pp. 192-195
Author(s):  
Dong Qi Liu ◽  
Ying Liu ◽  
Shu Fa Han ◽  
Yu Feng Zhang ◽  
Cui Yu Yin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sodium Alginate ◽  
Mechanical Performance ◽  
Viscose Fiber ◽  
Alginate Solution ◽  
Fiber Properties ◽  
Injection Methods ◽  
The Stability ◽  
Scanning Electron

In this article we successfully prepared calamine / sodium alginate viscose fiber. Good dispersion and stability of the modified solution was prepared by dispersing calamine in alkaline solution of sodium alginate, and then mixed it with viscose spinning solution by spinning injection methods. Moreover, the stability of calamine / sodium alginate solution, the effect of concentration of calamine on the fiber properties is studied in this paper. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and physical mechanical performance are test to characterize the structure and the performance of the calamine / sodium alginate viscose fiber.

scholarly journals Penetration of Different Impression Materials into Exposed Dentinal Tubules during the Impression Procedure

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1321 ◽  
Author(s):  
Bruna Sinjari ◽  
Gianmaria D’Addazio ◽  
Edit Xhajanka ◽  
Sergio Caputi ◽  
Giuseppe Varvara ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fractal Dimensions ◽  
Excellent Performance ◽  
Dentinal Tubules ◽  
Impression Materials ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
The Mean ◽  
Scanning Electron

Adhesive restorations have been shown to guarantee excellent performance and longevity, although this comes with some disadvantages. Among these, the vulnerability of dentine to different agents has been widely evaluated. The aim of this study was to evaluate the possible penetration of impression materials into freshly cut dentine. Dentine from 27 teeth was impressed with polyether (Impregum Penta L) (nine teeth) and with polyvinyl siloxane (Aquasil Ultra LV) (nine teeth). The surface of nine teeth after the impressions were used as the control. Specifically, the extroflections caused by the imprinting of the dentinal tubules on the impression material, the so-called impression tags, were measured. Furthermore, the presence of the material inside the tubules was examined. Scanning electron microscopy analysis showed material tags for all of the experimental groups. The mean lengths (±SD) were 22.6 (±11.0) µm for polyether, 21.8 (±12.8) µm for polyvinyl siloxane and 11.3 (±7.0) µm for the tooth control, with mean diameters (±SD) of 2.8 (±0.5), 2.4 (±0.7) and 3.1 (±0.7) µm, respectively. Fractal analysis showed fractal dimensions of 1.78 (±0.03), 1.77 (±0.03) and 1.71 (±0.03), respectively. These data demonstrated that the impression materials can remain inside the dentinal tubules, which can adversely affect the adhesive procedures.

scholarly journals Viability of Sirococcus clavigignenti-juglandacearum Conidia on Exoskeletons of Three Coleopteran Species

Plant Disease ◽  
2004 ◽  
Vol 88 (10) ◽  
pp. 1085-1091 ◽  
Author(s):  
J. E. Stewart ◽  
S. Halik ◽  
D. R. Bergdahl
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Vector Potential ◽  
Insect Species ◽  
Juglans Cinerea ◽  
The Mean ◽  
Scanning Electron ◽  
Butternut Canker

Butternut canker, caused by Sirococcus clavigignenti-juglandacearum, is the primary cause of decline of butternut (Juglans cinerea). Conidia of the fungus have been isolated from several insect species. The vector potential of three species of Coleoptera, Astylopsis macula, Eubulus parochus, and Glischrochilus sanguinolentus, was studied during 2001 and 2002. Beetles were collected, rinsed, and artificially inoculated with conidia. All three species carried viable conidia up to 16 days. The mean number of conidia carried per beetle in 2001 was as follows: 3.21 million at 0 h to 11,371 at 384 h for A. macula; 3.91 million at 0 h to 57 at 384 h for E. parochus; and 355,742 at 0 h to 314 at 384 h for G. sanguinolentus. In 2002, the numbers were: 1.42 million at 0 h to 2,814 at 384 h for A. macula; 1.29 million at 0 h to 85 at 384 h for E. parochus; and 72,342 at 0 h to 0 at 192 h for G. sanguinolentus. Using scanning electron microscopy, conidia were observed on the abdomen, thorax, and legs of artificially inoculated individuals of each species and on the thorax and abdomen of field-collected A. macula and E. parochus. These data suggest that all three species are potential vectors of S. clavigignenti-juglandacearum; however, A. macula and E. parochus may be more effective vectors.

scholarly journals New crosslinkers for electrospun chitosan fibre mats. I. Chemical analysis

2012 ◽  
Vol 9 (75) ◽  
pp. 2551-2562 ◽  
Author(s):  
Marjorie S. Austero ◽  
Amalie E. Donius ◽  
Ulrike G. K. Wegst ◽  
Caroline L. Schauer
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Mechanical Stability ◽  
Dissolution Tests ◽  
Natural Polysaccharide ◽  
Biomedical Field ◽  
The Stability ◽  
Scanning Electron

Chitosan (CS), the deacetylated form of chitin, the second most abundant, natural polysaccharide, is attractive for applications in the biomedical field because of its biocompatibility and resorption rates, which are higher than chitin. Crosslinking improves chemical and mechanical stability of CS. Here, we report the successful utilization of a new set of crosslinkers for electrospun CS. Genipin, hexamethylene-1,6-diaminocarboxysulphonate (HDACS) and epichlorohydrin (ECH) have not been previously explored for crosslinking of electrospun CS. In this first part of a two-part publication, we report the morphology, determined by field emission scanning electron microscopy (FESEM), and chemical interactions, determined by Fourier transform infrared microscopy, respectively. FESEM revealed that CS could successfully be electrospun from trifluoroacetic acid with genipin, HDACS and ECH added to the solution. Diameters were 267 ± 199 nm, 644 ± 359 nm and 896 ± 435 nm for CS–genipin, CS–HDACS and CS–ECH, respectively. Short- (15 min) and long-term (72 h) dissolution tests (T 600 ) were performed in acidic, neutral and basic pHs (3, 7 and 12). Post-spinning activation by heat and base to enhance crosslinking of CS–HDACS and CS–ECH decreased the fibre diameters and improved the stability. In the second part of this publication, we report the mechanical properties of the fibres.

Sign in / Sign up

Export Citation Format

Share Document