scholarly journals Mechanical strength of stainless steel and titanium alloy mini-implants with different diameters: an experimental laboratory study

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Sérgio Estelita Barros ◽  
Viviane Vanz ◽  
Kelly Chiqueto ◽  
Guilherme Janson ◽  
Eduardo Ferreira
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Stainless Steel ◽  
Titanium Alloy ◽  
Mechanical Strength ◽  
Null Hypothesis ◽  
Mini Implants ◽  
The Mean ◽  
Torsional Fracture ◽  
Scanning Electron

Abstract Background The mechanical strength of mini-implants is a critical factor due to their small diameters. Currently, it is not possible to state whether there is a relevant difference between the mechanical properties of stainless steel (SS-MIs) and titanium alloy mini-implants (TA-MIs). The objective of this study was to test the null hypothesis that there is no difference in the mechanical strength of SS-MIs and TA-MIs, and to analyze, by scanning electron microscopy (SEM), the SS-MI, and TA-MI threads resistance to morphological damage after insertion. Methods A standardized sample of 504 SS-MIs and TA-MIs with diameters ranging from 1.2 mm to 1.8 mm was used. Torsional fracture was performed in 154 MIs. Flexural strength of 280 MIs was evaluated at 1 mm and 2 mm-deflection. The threads of 70 MIs were morphologically analyzed by scanning electron microscopy (SEM), before and after their insertion in high-density artificial bone blocks. Comparisons between SS-MIs and TA-MIs were performed with t tests or Mann-Whitney U tests. A multiple linear regression analysis was used to evaluate the influence of variables on the ranging of MI mechanical strength. Results SS-MIs had higher fracture torque. The mean difference between the SS-MIs and TA-MIs fracture torque was of 4.09 Ncm. The MI diameter explained 90.3% of the total variation in fracture torque, while only 2.2% was explained by the metallic alloy. The SS-MI group presented a higher deformation force during the 1mm and 2mm-deflection. The mean difference between the flexural strength of SS and TA-MIs at 1 mm and 2 mm-deflection was of 18.21 N and 17.55 N, respectively. There was no noticeable morphological damage to the threads of SS-MIs and TA-MIs. Conclusions The null hypothesis was rejected. SS-MIs were 13.2% and 20.2% more resistant to torsional fracture and deflection, respectively. The threads of the SS-MIs and TA-MIs were not damaged during the insertion and removal process. Thus, the use of SS-MI can reduce the fracture risk without increasing the MI diameter.

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 Influence of the Treatment Temperature on the Microstructure and Hydration Behavior of Thermoactivated Recycled Cement

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3937
Author(s):  
Sofia Real ◽  
Ana Carriço ◽  
José Alexandre Bogas ◽  
Mafalda Guedes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Strength ◽  
Water Demand ◽  
Isothermal Calorimetry ◽  
Setting Time ◽  
Treatment Temperature ◽  
Diffraction Field ◽  
Resonance Spectroscopy ◽  
Scanning Electron

This paper intends to contribute to a better knowledge of the production and rehydration of thermoactivated recycled cement and its incorporation in cement-based materials. To this end, the influence of the treatment temperature on the properties of recycled cements and recycled cement pastes was assessed by means of a wide array of tests. Anhydrous recycled cement as well as the resulting pastes were characterized through density and particle size, water demand and setting time, thermogravimetry, X-ray diffraction, field emission gun scanning electron microscopy, isothermal calorimetry, 29Si nuclear magnetic resonance spectroscopy, flowability, mechanical strength, mercury intrusion porosimetry and scanning electron microscopy. The treatment temperature had a significant influence on the dehydration and hydration of recycled cement, essentially resulting in the formation of C2S polymorphs of varying reactivity, which led to pastes of different fresh and hardened behaviors. The high water demand and the pre-hydration of recycled cement resulted in high setting times and low compressive strengths. The highest mechanical strength was obtained for a treatment temperature of 650 °C.

Analyse of Indium Loss in Preparation of CuInSe2 Flims for Solar Cells

2011 ◽  
Vol 183-185 ◽  
pp. 1837-1841
Author(s):  
Lei Sha ◽  
Yan Lai Wang ◽  
Shi Liang Ban
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Stainless Steel ◽  
Solar Cells ◽  
Surface Morphology ◽  
Energy Dispersive Spectroscopy ◽  
Titanium Substrates ◽  
Selenization Process ◽  
Scanning Electron

CuInSe2 thin films were obtained by selenization of the Cu-In precursors in the atmosphere of Se vapour, which were prepared on stainless steel and titanium substrates by electrodeposition. The films were characterized by XRD, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The respective influences of composition, phases and surface morphology of Cu-In precursors on indium loss were investigated. The results indicate that the indium loss occurs in selenization process because of volatile In2Se arising. The indium loss is less in selenization process of Cu-In precursors contained CuIn, Cu2In and In phases.

Research on the Adhesion of Stainless Steel Film on Gd by Magnetron Sputtering

2011 ◽  
Vol 189-193 ◽  
pp. 129-136
Author(s):  
Xiao Qiu Zheng ◽  
Shi Kun Xie ◽  
Rong Xi Yi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Stainless Steel ◽  
Magnetron Sputtering ◽  
Protective Coating ◽  
Tension Test ◽  
Dc Magnetron Sputtering ◽  
Thin Fiber ◽  
Scanning Electron ◽  
Strength Of Adhesion

In order to research the adhesion of sputtering protective coating of Gd. Gd substrates was coated with 1Cr18Ni9Ti by means of DC magnetron sputtering technology. The characteristics of the film were investigated by scanning electron microscopy (SEM), EDS, SPM and the adhesions of film was tested by tension test. The results show that the films of 1Cr18Ni9Ti are distributed by means of islands when the sputtering was initiated and the grains are like thin fiber. After a few minutes, the films are smooth and perfect, the interferences between 1Cr18Ni9Ti and Gd join together strongly, and the largest strength of adhesion is 24.7MPa when the sputtering density is 966 w/cm2 and the sputtering time is 8 minutes.

Scanning Electron Microscopy of Microbial Attachment to Milk Contact Surfaces1

1981 ◽  
Vol 44 (3) ◽  
pp. 204-208 ◽  
Author(s):  
P. T. ZOLTAI ◽  
E. A. ZOTTOLA ◽  
L. L. MCKAY
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Stainless Steel ◽  
Fibrous Material ◽  
Microbial Colonization ◽  
Lactobacillus Bulgaricus ◽  
Stainless Steel Surface ◽  
Pseudomonas Fragi ◽  
Scanning Electron ◽  
Microbial Attachment

Milk contact surfaces were observed by scanning electron microscopy (SEM) techniques for possible microbial attachment. Cultures of Pseudomonas fragi 4973, Staphylococcus aureus JAL, Streptococcus lactis C2, Streptococcus cremoris and Lactobacillus bulgaricus RR inoculated onto glass coverslips or stainless steel chips were examined. Stainless steel surfaces displayed many possible harborages for microbial colonization. SEM examination of P. fragi 4973 showed development of fibrous material, with numerous stick-like projections extending from the cell to the glass or stainless steel surface. These apparent attachment appendages became more pronounced as contact time increased. S. aureus, S. lactis, S. cremoris and L. bulgaricus did not display such fibrous material.

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.

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