scholarly journals Properties of Orthodontic Clear Aligner Materials - A Review

2021 ◽  
Vol 10 (37) ◽  
pp. 3288-3294
Author(s):  
Binu Punnoose Gold ◽  
Suvetha Siva ◽  
Sangeetha Duraisamy ◽  
Azmina Idaayath ◽  
Ravi Kannan
Keyword(s):  
Mechanical Properties ◽  
Optical Properties ◽  
Orthodontic Treatment ◽  
Thermoplastic Material ◽  
Lingual Orthodontics ◽  
White Spots ◽  
Before And After ◽  
Materials Used ◽  
Orthodontic Devices ◽  
Clear Aligner

BACKGROUND Clear aligners are orthodontic devices that are transparent, a plastic used to correct malaligned teeth. Here patient wears a series of customized clear, removable aligners that gradually move the teeth to the desired position. The clear aligner system is a modern adaptation of the systems described since the middle of the 20th century, therefore there were different devices and philosophies that have led to its creation and the system has evolved a lot over the decades. Clear aligner therapy has been a part of the orthodontic practice for years, but, popularity was increased since the introduction of Invisalign appliances (Align Technology) in 1998. There are almost 27 different clear aligner products currently on offer for orthodontic treatment. Nowadays, more people prefer clear aligner treatment because it is aesthetically superior to brackets and lingual orthodontics. The superiority of clear aligners lies in their aesthetics. The optical properties of the clear aligner material play a major role in aesthetics. The rising demand among adult patients for “invisible” orthodontic treatment has led to an exponential growth in the clear aligner market. Indeed, these aligners have a low aesthetic impact, as well as being able to effectively and progressively guide the teeth into their programmed positions. They are also removable and therefore do not hamper oral hygiene maintenance, in turn reducing the risk of white spots, caries, gingivitis and periodontal disease. All the materials do not possess the same chemical composition. The properties change before and after wear. In this article, we bring out the different materials used for the manufacture of clear aligners and their various properties. KEY WORDS Clear Aligners, Optical Properties, Thermoplastic Material, Mechanical Properties

scholarly journals Comparative Microstructural Study on Mechanical Properties of Concrete Enhanced with Graphite and Graphene Compound

2018 ◽  
Vol 7 (4.5) ◽  
pp. 91
Author(s):  
P. Sudheer ◽  
Dr S. Chandramouli
Keyword(s):  
Mechanical Properties ◽  
Raw Materials ◽  
Chemical Properties ◽  
Nano Materials ◽  
Nano Technology ◽  
Microstructural Investigation ◽  
Before And After ◽  
Materials Used ◽  
Physical And Chemical ◽  
And Chemical Properties

The present study is based on nano technology and came up with the idea of introducing nanoparticles in the raw materials used for construction. Nano materials are available in three principal shapes 0, 1 and 2 Dimensional nanoparticles. 0D and 1D nanofibers are such as carbon nanotubes and nanosilica compounds. This study has investigated the physical and chemical properties of graphite and graphene compound and its applicability in construction industry.  Graphene has created interest as it is believed to improve the strength of concrete allowing the possibility of controlling properties of concrete. In this work graphene is used as a reinforcing additive in cement-based mortar and concrete. Own Graphene compound is prepared using conventional graphite and concentrated hydrogen peroxide in the laboratory due to the unavailability of graphene. As a part of microstructural investigation, SEM and EDS analysis on graphite and graphene compounds before and after implementation are carried out in the laboratory. Then the two compounds are replaced as a part of small percentage in cement mortar cubes casted for various proportions. The mechanical properties of cement-based composites are studied after incorporating of graphite and graphene compounds at low dosages in concrete and then the results are compared. 

scholarly journals Buccolingual Inclination Control of Upper Central Incisors of Aligners: A Comparison with Conventional and Self-Ligating Brackets

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Maria Francesca Sfondrini ◽  
Paola Gandini ◽  
Tommaso Castroflorio ◽  
Francesco Garino ◽  
Luca Mergati ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Orthodontic Treatment ◽  
Radiographic Evaluation ◽  
Before And After ◽  
Conventional Brackets ◽  
Angular Measurements ◽  
Orthodontic Devices

Objective. The upper incisors torque expression is essential for the orthodontic treatment accuracy. Various orthodontic devices are claimed to have different inclination control capacity. The purpose of this retrospective study was to compare the radiographic buccolingual inclination of upper incisors in patients treated with three different orthodontic techniques. Material and Methods. Conventional brackets (Victory, 3M), self-ligating appliances (Damon Q, Ormco), and aligners (Invisalign, Align Technology) were tested. Cephalometric data of 25 patients with similar skeletal and dental pretreatment parameters were collected for each technique. Position changes of upper central incisors were assessed with radiographic evaluation before and after therapy. Three different parameters were considered: 11∧SnaSnp, 11∧Ocl and I+ TVL. All variables were measured before (T0) and after (T1) treatment and their variation over treatment was assessed. Results. When evaluating angular measurements, 11∧SnaSnp and 11∧Ocl angles showed the highest numeric variation with conventional brackets. Lowest values were reported with aligners. However, the differences among various techniques were not significant for both angles (P>0.05). Also I+ TVL linear value variation did not show significant differences among the different groups tested (P>0.05). Conclusion. Conventional multibrackets appliance showed the highest incisal position variations over treatment, but the differences among various groups were not significantly different.

Assessment of the compressive and tensile mechanical properties of materials used in the Jaipur Foot prosthesis

2018 ◽  
Vol 42 (5) ◽  
pp. 511-517 ◽  
Author(s):  
Rachel H Teater ◽  
Kristine M Fischenich ◽  
Benjamin B Wheatley ◽  
Lisa Abrams ◽  
Sheryl A Sorby ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Global Scale ◽  
Tire Cord ◽  
Future Design ◽  
Design And Manufacturing ◽  
Before And After ◽  
Properties Of Materials ◽  
Materials Used ◽  
And Function

Background: Designed by Dr. Sethi, the Jaipur Foot prosthesis is ideally suited for amputees in developing countries as it utilizes locally sourced, biodegradable, inexpensive materials and is focused on affordability and functionality. To date, however, no data have been reported on the material properties of the foot components. Objectives: The goal of this work was to evaluate mechanical properties of the Jaipur Foot components to guide foot design and manufacturing and reduce weight. Study Design: Experimental. Methods: Mechanical testing was conducted on two types of woods (ardu and cheed), microcellular rubber, tire cord, cushion compound, tread compound, and skin-colored rubber. Each material was subjected to testing in either tension or compression based on its location and function in the foot. Samples were tested before and after vulcanization. Two-sample t-tests were used to assess statistical differences. Results: Cheed compressed perpendicular to the grain had a significantly higher modulus of elasticity than ardu ( p < 0.05); however, cheed had a higher density. Vulcanization significantly increased the modulus of skin-colored rubber, cushion compound, and tread compound ( p < 0.05) and decreased the moduli of both microcellular rubber and tire cord ( p < 0.05). Conclusion: The material property results from this study provide information for computer modeling to assess material construction on overall foot mechanics for design optimization. Ardu wood was ideal based on the desire to reduce weight, and the tire cord properties serve well to hold the foot together. Clinical relevance With new knowledge on the material properties of the components of the Jaipur Foot, future design modifications and standardized fabrication can be realized, making the Jaipur Foot more available on a global scale.

scholarly journals Clear aligner therepy – A review

2021 ◽  
Vol 9 (2) ◽  
pp. 46-52
Author(s):  
Sanjana Shetty ◽  
Naazia Shaikh
Keyword(s):  
Orthodontic Treatment ◽  
Tooth Movement ◽  
Primary Concern ◽  
Lingual Orthodontics ◽  
Custom Made ◽  
Progressive Force ◽  
Clear Aligner ◽  
Metal Wires

Aesthetics is a major factor in Orthodontic treatment and it is a primary concern among patients seeking orthodontic treatment. To meet the growing aesthetic desire for an alternative to traditional braces, researchers have created a variety of alternatives, including ceramic or composite braces, lingual orthodontics, and transparent aligners. Clear aligner therapy is a treatment that consists of a set of clear dental appliances that are custom-made to fit the contour of a patient's teeth. Clear Aligners are an alternative to traditional braces that are used to guide teeth into appropriate alignment. Clear aligners, like braces, utilise a progressive force to regulate tooth movement, but without the need of metal wires or brackets.

scholarly journals Effect of clear aligner therapy on the buccolingual inclination of mandibular canines and the intercanine distance

2015 ◽  
Vol 86 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Thorsten Grünheid ◽  
Sara Gaalaas ◽  
Hani Hamdan ◽  
Brent E. Larson
Keyword(s):  
Orthodontic Treatment ◽  
Statistical Significance ◽  
Cone Beam ◽  
Fixed Appliance ◽  
Before And After ◽  
Fixed Appliances ◽  
Clear Aligner ◽  
Intercanine Distance

ABSTRACT Objective:  To compare the changes in buccolinugal inclination of mandibular canines and intercanine distance in patients treated with clear aligners to those treated with preadjusted edgewise appliances. Materials and Methods:  The buccolingual inclination of mandibular canines and the intercanine distance were measured on pre- and posttreatment cone-beam computed tomograms of 30 patients who had been treated with clear aligners and 30 patients who had been treated with fixed preadjusted edgewise appliances. Differences between the aligner and fixed appliance groups and between pre- and posttreatment measurements were tested for statistical significance. Results:  In both groups, most of the mandibular canines had positive buccolingual inclinations (ie, their crowns were positioned lateral to their roots) both before and after treatment. While there was no difference between the groups pretreatment, the posttreatment buccolingual inclination was significantly greater in the aligner group. In the fixed appliance group, the canines became more upright with treatment, while the buccolingual inclination did not change significantly in the clear aligner group. The intercanine distance did not differ between the groups either before or after treatment. However, it increased significantly over the course of treatment in the aligner group, whereas it did not change significantly in the fixed appliance group. Conclusions:  Orthodontic treatment with clear aligners tends to increase the mandibular intercanine distance with little change in inclination in contrast to treatment with fixed appliances, which leaves the intercanine distance unchanged but leads to more upright mandibular canines.

Deformation Replication

1970 ◽  
Vol 28 ◽  
pp. 280-281
Author(s):  
J. Temple Black
Keyword(s):  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Rake Face ◽  
Orthogonal Machining ◽  
Aluminum Chips ◽  
Before And After ◽  
Materials Used ◽  
Glass Knife ◽  
Very High

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.

Perbedaan Analisis Sefalometri Skeletal Sebelum dan Sesudah Perawatan Alat Myofunctional pada Pasien Maloklusi Dentoskeletal Kelas II Divisi I dalam Masa Pertumbuhan dengan Metode Steiner

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Nugroho Ahmad Riyadi
Keyword(s):  
Orthodontic Treatment ◽  
Class Ii ◽  
T Test ◽  
Analytic Study ◽  
Statistic Analysis ◽  
Twin Block ◽  
Normal Occlusion ◽  
Division 1 ◽  
Before And After ◽  
Class Ii Division 1

The aim of orthodontics treatment is normalization of teeth position in three planes, using various orthodontics appliance to reach the chepalometric standar and normal occlusion. Orthodontic treatment for dentoskeletal class II division 1 malocclusion in growing patients using myofunctional appliance may correct anteroposterior planes of mandibula. This study was a descriptive retrospective analytic study to look at the success of Orthodontic treatment for dentoskeletal class II division 1 in growing patients with myofunctional appliance using chepalometrics analysis Steiner value. The sample used in this study is chepalogram radiographic from patient with dentoskeletal class II division 1 malocclusion in growing patients before and after using myofunctional appliance in PPDGS orthodontics Clinic of Padjadjaran University. Statistic analysis were performed with pair t-test and Wilcoxon. Based on this study, it is concluded that orthodontic treatment with myofunctional appliance such as activator and twin block in growing patient with dentoskeletal class II division 1 malocclusion shows significant changes and compatibility with the normal criteria.

Emerging Techniques for the Characterization of Nano-Mechanical Properties of Integrated Circuit Components

2008 ◽  
Author(s):  
Nicholas Randall ◽  
Rahul Premachandran Nair
Keyword(s):  
Mechanical Properties ◽  
Quality Control ◽  
Integrated Circuits ◽  
Integrated Circuit ◽  
Manufacturing Process ◽  
Solder Bumps ◽  
Initial Work ◽  
Circuit Components ◽  
Materials Used

Abstract With the growing complexity of integrated circuits (IC) comes the issue of quality control during the manufacturing process. In order to avoid late realization of design flaws which could be very expensive, the characterization of the mechanical properties of the IC components needs to be carried out in a more efficient and standardized manner. The effects of changes in the manufacturing process and materials used on the functioning and reliability of the final device also need to be addressed. Initial work on accurately determining several key mechanical properties of bonding pads, solder bumps and coatings using a combination of different methods and equipment has been summarized.

Sunlight exposure: the effects on the performance of paragliding fabric

2018 ◽  
Vol 69 (05) ◽  
pp. 381-389
Author(s):  
MENGÜÇ GAMZE SÜPÜREN ◽  
TEMEL EMRAH ◽  
BOZDOĞAN FARUK
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Air Permeability ◽  
Sunlight Exposure ◽  
Test Results ◽  
Coating Materials ◽  
Strength Tests ◽  
Before And After ◽  
The Relationship ◽  
Dark Blue

This study was designed to explore the relationship between sunlight exposure and the mechanical properties of paragliding fabrics which have different colors, densities, yarn counts, and coating materials. This study exposed 5 different colors of paragliding fabrics (red, turquoise, dark blue, orange, and white) to intense sunlight for 150 hours during the summer from 9:00 a.m. to 3:00 p.m. for 5 days a week for 5 weeks. Before and after the UV radiation aging process, the air permeability, tensile strength, tear strength, and bursting strength tests were performed. Test results were also evaluated using statistical methods. According to the results, the fading of the turquoise fabric was found to be the highest among the studied fabrics. It was determined that there is a significant decrease in the mechanical properties of the fabrics after sunlight exposure. After aging, the fabrics become considerably weaker in the case of mechanical properties due to the degradation in both the dyestuff and macromolecular structure of the fiber

EVALUATION OF TRIBOTECHNICAL PROPERTIES OF THE COATING OBTAINED BY ELECTRIC SPARK HARDENING

2020 ◽  
Vol 4 (141) ◽  
pp. 157-163
Author(s):  
IL’YA ROMANOV ◽  
◽  
ROMAN ZADOROZHNIY
Keyword(s):  
Wear Resistance ◽  
Reference Sample ◽  
Optical Microscope ◽  
Research Purpose ◽  
Tribotechnical Properties ◽  
Uncoated Surface ◽  
Before And After ◽  
Materials Used ◽  
Friction Track

When applying coatings using various methods on the surfaces of moving parts that work in joints, it is important to make sure that the coatings are strong and wear-resistant in order to return them to their original resource. All existing hardening technologies and materials used to perform coatings have their own characteristics, therefore, the quality of the resulting coatings can be judged only after specific tests. (Research purpose) The research purpose is in evaluating the properties of the coating obtained by the method of electric spark hardening, and its ability to resist friction and mechanical wear. (Materials and methods) Authors conducted tests on the basis of the "Nano-Center" center for collective use. A coating was applied on the BIG-4M unit with a VK-8 hard alloy electrode, tribological properties were evaluated on a CSM Instruments TRB-S-DE-0000 tribometer, the width of the friction track was measured after the test using an inverted OLYMPUS gx51 optical microscope, and samples were weighed before and after the test on a VLR-200 analytical balance. Conducted research in accordance with GOST 23.224-86 and RD 50-662-88 guidelines. (Results and discussion) The article presents performed tests on the run-in and wear resistance of the coating. The samples were worked on with a step-by-step increase in the load. During the tests, the friction force was drawed on the diagram. Authors compared the results with the reference sample, an uncoated surface. (Conclusions) The resulting coating has better run-in and wear resistance compared to the standard, and the increase in wear resistance in dry friction conditions is very significant.

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