scholarly journals Insertion torque versus mechanical resistance of mini- implants inserted in different cortical thickness

2014 ◽  
Vol 19 (3) ◽  
pp. 90-94 ◽  
Author(s):  
Renata de Faria Santos ◽  
Antonio Carlos de Oliveira Ruellas ◽  
Daniel Jogaib Fernandes ◽  
Carlos Nelson Elias
Keyword(s):  
Surface Morphology ◽  
Cortical Thickness ◽  
Smooth Surface ◽  
Mechanical Tests ◽  
Sem Analysis ◽  
Mechanical Resistance ◽  
Insertion Torque ◽  
Mini Implants ◽  
Before And After ◽  
Torsional Fracture

OBJECTIVE: This study aimed to measure insertion torque, tip mechanical resistance to fracture and transmucosal neck of mini-implants (MI) (Conexão Sistemas de PróteseT), as well as to analyze surface morphology. METHODS: Mechanical tests were carried out to measure the insertion torque of MIs in different cortical thicknesses, and tip mechanical resistance to fracture as well as transmucosal neck of MIs. Surface morphology was assessed by scanning electron microscopy (SEM) before and after the mechanical tests. RESULTS: Values of mechanical resistance to fracture (22.14 N.cm and 54.95 N.cm) were higher and statistically different (P < 0.05) from values of insertion torque for 1-mm (7.60 N.cm) and 2-mm (13.27 N.cm) cortical thicknesses. Insertion torque was statistically similar (P > 0.05) to torsional fracture in the tip of MI (22.14 N.cm) when 3 mm cortical thickness (16.11 N.cm) and dense bone (23.95 N.cm) were used. Torsional fracture of the transmucosal neck (54.95 N.cm) was higher and statistically different (P < 0.05) from insertion torsional strength in all tested situations. SEM analysis showed that the MIs had the same smooth surface when received from the manufacturer and after the mechanical tests were performed. Additionally, no significant marks resulting from the manufacturing process were observed. CONCLUSION: All mini-implants tested presented adequate surface morphology. The resistance of mini-implants to fracture safely allows placement in 1 and 2-mm cortical thickness. However, in 3-mm cortical thickness and dense bones, pre-drilling with a bur is recommended before insertion.

Influence of the Geometric Characteristics of the Mini-Implants on Mechanicals Properties Using Artificial Bone Similar to Anterior, Middle and Posterior Regions of the Jaws

2018 ◽  
Vol 930 ◽  
pp. 276-282
Author(s):  
E.I.O. Pesqueira ◽  
Cristiano Stefano Mucsi ◽  
Jesualdo Luiz Rossi
Keyword(s):  
Bone Density ◽  
Cortical Thickness ◽  
Insertion Torque ◽  
Trabecular Thickness ◽  
Mini Implants ◽  
Torque Wrench ◽  
Artificial Bones ◽  
Before And After ◽  
Twin Screw ◽  
Torque Values

The objective of this study was to identify the best torque of insertion and removal of mini-implants with a twin screw design (compact and self-drilling) into artificial bones with density and trabecular thickness, similar to anterior, middle and posterior regions of the jaws. Observation of the mini-implants surface using electron microscopy was performed before and after the tests. The torque values obtained during the insertion and removal was measured by digital torque wrench. The analyzed results led to the conclusion that the insertion and removal torques were larger with increase in bone density and cortical thickness. The design of the threads of the mini-implants influenced the insertion torque. Threads with smaller pitch increased the value of insertion torque. The anterior bone drilling installation reduces the insertion torque independent of bone density. Torque increased mainly by increasing the bone density and not necessarily with increased cortical thickness suggesting that the bone density of the trabecular bone must be considered in designing the installation of mini-implants.

SEM-EDS Analysis of Composite Al2O3-ZrO2 Ceramics Eroded with SiC Particles

2015 ◽  
Vol 729 ◽  
pp. 27-31
Author(s):  
Kresimir Grilec ◽  
Lidija Curkovic ◽  
Marijana Majic Renjo ◽  
Suzana Jakovljevic ◽  
Matija Sakoman ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Surface Morphology ◽  
Tribological Properties ◽  
Slip Casting ◽  
Sample Surface ◽  
Impact Angle ◽  
Sem Analysis ◽  
Electric Kiln ◽  
Eds Analysis ◽  
Before And After

In this paper, composite Al2O3–t-ZrO2ceramics (composition: 95 wt. % Al2O3– 5 wt. % t-ZrO2and 90 wt. % Al2O3– 10 wt. % t-ZrO2) was formed by slip casting in plaster mould. After drying, green bodies were sintered in laboratory electric kiln under air environment at a temperature of 1650 °C.Erosive wear resistance of sintered monolithic Al2O3and composite Al2O3–t-ZrO2ceramics was determined by SEM analysis of the sample surface morphology before and after erosion at impact angle of 90° and SiC as erodent particles. Surface morphology analysis after erosion showed that wear scars were significantly larger on Al2O3than on Al2O3–t-ZrO2samples. All conducted tests showed that tribological properties of monolithic Al2O3can be improved with the addition of t-ZrO2.

scholarly journals Fracture strength of orthodontic mini-implants

2017 ◽  
Vol 22 (3) ◽  
pp. 47-54 ◽  
Author(s):  
Tatiana Feres Assad-Loss ◽  
Flávia Mitiko Fernandes Kitahara-Céia ◽  
Giordani Santos Silveira ◽  
Carlos Nelson Elias ◽  
José Nelson Mucha
Keyword(s):  
Fracture Strength ◽  
Testing Machine ◽  
Insertion Torque ◽  
Outer Diameter ◽  
Apical Region ◽  
Fracture Test ◽  
Mini Implants ◽  
Inner Diameter ◽  
Torque Values ◽  
Torsional Fracture

ABSTRACT Objective: This study aimed at evaluating the design and dimensions of five different brands of orthodontic mini-implants, as well as their influence on torsional fracture strength. Methods: Fifty mini-implants were divided into five groups corresponding to different manufactures (DEN, RMO, CON, NEO, SIN). Twenty-five mini-implants were subjected to fracture test by torsion in the neck and the tip, through arbors attached to a Universal Mechanical Testing Machine. The other 25 mini-implants were subjected to insertion torque test into blocks of pork ribs using a torquimeter and contra-angle handpiece mounted in a surgical motor. The shape of the active tip of the mini-implants was evaluated under microscopy. The non-parametric Friedman test and Snedecor’s F in analysis of variance (ANOVA) were used to evaluate the differences between groups. Results: The fracture torque of the neck ranged from 23.45 N.cm (DEN) to 34.82 N.cm (SIN), and of the tip ranged from 9.35 N.cm (CON) to 24.36 N.cm (NEO). Insertion torque values ranged from 6.6 N.cm (RMO) to 10.2 N.cm (NEO). The characteristics that most influenced the results were outer diameter, inner diameter, the ratio between internal and external diameters, and the existence of milling in the apical region of the mini-implant. Conclusions: The fracture torques were different for both the neck and the tip of the five types evaluated. NEO and SIN mini-implants showed the highest resistance to fracture of the neck and tip. The fracture torques of both tip and neck were higher than the torque required to insert mini-implants.

Effect of Different Cleaning and Sterilization Methods on the Surface Morphology of Mini-implants

2017 ◽  
Vol 68 (9) ◽  
pp. 1974-1977
Author(s):  
Silvia Izabella Pop ◽  
Dana Cristina Bratu ◽  
Violeta Valentina Merie ◽  
Mariana Pacurar ◽  
Catalin Petru Simon ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Surface Topography ◽  
Distilled Water ◽  
Mini Implants ◽  
Cleaning Methods ◽  
Sem Analyses

The objective of this study was to analyse morphological and surface topography variations of two types of mini-implants after using different chemical and physical cleaning methods and autoclaved sterilization. One hundred mini-implants from two different manufacturers were used in this study. The mini-implants from each manufacturer were divided in five groups, each consisting of ten samples: G0 new, unused, G1 ultrasonically cleaned, G2 chemically cleaned, G3 sandblasted, G4 cleaned with distilled water. SEM analyses of the mini-implants were performed. Only procedures used in samples from group G2 and G3 removed the tissue remains from the mini-implants surface.

Fullerene-like Nanoparticles of WS2 as a Promising Protection from Erosive Wear of Gun Bore Nozzles

2020 ◽  
Vol 16 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Narimane Rezgui ◽  
Danica Simić ◽  
Choayb Boulahbal ◽  
Dejan Micković
Keyword(s):  
Mass Loss ◽  
Solid Lubricant ◽  
Erosive Wear ◽  
Mechanical Resistance ◽  
Protective Function ◽  
Protective Layers ◽  
Total Mass Loss ◽  
Mass Losses ◽  
Before And After ◽  
Tube Life

Background: Erosive wear causes increase in the bore diameter of firearms barrels and nozzles. Most responsible factors for this erosion are friction and heat generated during the shot. Protection from erosive wear is very important for gun tube life cycle, and various protection methods are used: adding phlegmatizers in gunpowder composition or applying protective layers on the gun bore inner surface. Objective: In this research, a possibility is examined to protect the surface of a nozzle exposed to gunpowder erosion applying a layer of tungsten disulfide fullerene-like nanoparticles, IF-WS2, known as outstanding solid lubricant of a great mechanical resistance. Methods: Nanoparticles on the nozzle surface before and after the gunfire tests were observed using scanning electron microscopy/energy dispersive X-ray spectroscopy. Gunfire tests were performed on designed erosion device. Temperatures in the defined position near the affected surface were measured with thermocouples and compared for the nozzles with and without nanoprotection, as well as the nozzle mass loss after each round. Results: For the sample with IF-WS2 lower temperatures after firing and lower mass losses were observed. Mass loss after first round was 25.6% lower for the sample with protective nanoparticles layer, and the total mass loss was about 5% lower after five rounds. After the first round the nozzle without IF-WS2 was heated up to a temperature which was for 150.8°C higher than the nozzle with IF-WS2. Conclusion: Protective function of IF-WS2 is the most pronounced for the first round. The observed results encourage its further application in firearms gun bores protection.

scholarly journals Fast Preparation of High-Performance Wood Materials Assisted by Ultrasonic and Vacuum Impregnation

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 567
Author(s):  
Hong Yang ◽  
Mingyu Gao ◽  
Jinxin Wang ◽  
Hongbo Mu ◽  
Dawei Qi
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Mechanical Tests ◽  
Vacuum Impregnation ◽  
Natural Forests ◽  
Ultrasonic Pretreatment ◽  
Fast Growing ◽  
Before And After ◽  
New Material ◽  
Ft Ir

In the absence of high-quality hardwood timber resources, we have gradually turned our attention from natural forests to planted fast-growing forests. However, fast-growing tree timber in general has defects such as low wood density, loose texture, and poor mechanical properties. Therefore, improving the performance of wood through efficient and rapid technological processes and increasing the utilization of inferior wood is a good way to extend the use of wood. Densification of wood increases the strength of low-density wood and extends the range of applications for wood and wood-derived products. In this paper, the effects of ultrasonic and vacuum pretreatment on the properties of high-performance wood were explored by combining sonication, vacuum impregnation, chemical softening, and thermomechanical treatments to densify the wood; then, the changes in the chemical composition, microstructure, and mechanical properties of poplar wood before and after treatment were analyzed comparatively by FT-IR, XRD, SEM, and mechanical tests. The results showed that with ultrasonic pretreatment and vacuum impregnation, the compression ratio of high-performance wood reached its highest level and the MOR and MOE reached their maximums. With the help of this method, fast-growing softwoods can be easily prepared into dense wood materials, and it is hoped that this new material can be applied in the fields of construction, aviation, and automobile manufacturing.

Flammability, morphological and mechanical properties of sugar palm fiber/polyester yarn-reinforced epoxy hybrid biocomposites with magnesium hydroxide flame retardant filler

2021 ◽  
pp. 004051752110086
Author(s):  
MJ Suriani ◽  
SM Sapuan ◽  
CM Ruzaidi ◽  
DS Nair ◽  
RA Ilyas
Keyword(s):  
Tensile Strength ◽  
Surface Morphology ◽  
Flame Retardant ◽  
Tensile Properties ◽  
Magnesium Hydroxide ◽  
Building Materials ◽  
Epoxy Composite ◽  
Sem Analysis ◽  
Palm Fiber ◽  
Sugar Palm Fiber

This paper aims to study the surface morphology, flammability and tensile properties of sugar palm fiber (SPF) hybrid with polyester (PET) yarn-reinforced epoxy composite with the addition of magnesium hydroxide (Mg(OH)2) as a flame retardant. The composites were prepared by hybridized epoxy and Mg(OH)2/PET with different amounts of SPF contents (0%, 20%, 35% and 50%) using the cold press method. Then these composites were tested by horizontal burning analysis, tensile strength testing and scanning electron microscopy (SEM) analysis. The specimen with 35% SPF (Epoxy/PET/SPF-35) with the incorporation of Mg(OH)2 as a flame retardant showed the lowest burning rate of 13.25 mm/min. The flame took a longer time to propagate along with the Epoxy/PET/SPF-35 specimen and at the same time producing char. Epoxy/PET/SPF-35 also had the highest tensile strength of 9.69 MPa. Tensile properties of the SPF hybrid with PET yarn (SPF/PET)-reinforced epoxy composite was decreased at 50% SPF content due to the lack of interfacial bonding between the fibers and matrix. Surface morphology analysis through SEM showed uniform distribution of the SPF and matrix with less adhesion, which increased the flammability and reduced the tensile properties of the hybrid polymeric composites. These composites have potential to be utilized in various applications, such as automotive components, building materials and in the aerospace industry.

Electronic irradiation of TlInSxSe2−x (x = 1): Morphology, structure and raman scattering

2021 ◽  
Author(s):  
M. Yu. Tashmetov ◽  
F. K. Khallokov ◽  
N. B. Ismatov ◽  
I. I. Yuldashova ◽  
S. Kh. Umarov
Keyword(s):  
Surface Morphology ◽  
Single Crystal ◽  
Single Phase ◽  
Phase State ◽  
Monoclinic Structure ◽  
Average Value ◽  
Single Phase State ◽  
Before And After ◽  
Electronic Irradiation ◽  
The Difference

It is shown that the replacement of a part of sulfur atoms with selenium atoms in a TlInS2 single crystal stimulates the formation of a single-phase state with a monoclinic structure (space group [Formula: see text]/[Formula: see text] in TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]). Irradiation with 2 MeV electrons and a fluence of [Formula: see text] electron/cm2 of powder TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) leads to an increase in the crystallite size from 56.5 nm to 65 nm, which is most likely associated with a decrease in the interface. The difference between the surface morphology of the synthesized TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal and the surface morphology of the TlInS2 single crystal is established, which consists in a decrease in the height and width of the roughness in TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]). Irradiation of a TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal with electrons with a fluence of [Formula: see text] electron/cm2 does not lead to a change in the height of the tubercle on its surface, and the average value of its width increases more than ten-fold. The identity of the peaks in the Raman spectra of the TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal before and after its irradiation with electrons with an energy of 2 MeV and upto a fluence of [Formula: see text] electron/cm2, along with the absence of a shift of the peaks, indicates the radiation resistance of the TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal.

scholarly journals Surface Morphology and Electrical Properties of Cu3BTC2 Thin Films Before and After Reaction with TCNQ

2018 ◽  
Vol 10 (45) ◽  
pp. 39400-39410 ◽  
Author(s):  
Konrad Thürmer ◽  
Christian Schneider ◽  
Vitalie Stavila ◽  
Raymond W. Friddle ◽  
François Léonard ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Surface Morphology ◽  
Before And After

scholarly journals Ultrasonic, Molecular and Mechanical Testing Diagnostics in Natural Fibre Reinforced, Polymer-Stabilized Earth Blocks

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
C. Galán-Marín ◽  
C. Rivera-Gómez ◽  
F. Bradley
Keyword(s):  
Soil Stabilization ◽  
Ultrasonic Pulse Velocity ◽  
Mechanical Tests ◽  
Pulse Velocity ◽  
Mechanical Resistance ◽  
Chemical Compositions ◽  
Natural Polymer ◽  
Natural Polymers ◽  
X Ray ◽  
Earth Blocks

The aim of this research study was to evaluate the influence of utilising natural polymers as a form of soil stabilization, in order to assess their potential for use in building applications. Mixtures were stabilized with a natural polymer (alginate) and reinforced with wool fibres in order to improve the overall compressive and flexural strength of a series of composite materials. Ultrasonic pulse velocity (UPV) and mechanical strength testing techniques were then used to measure the porous properties of the manufactured natural polymer-soil composites, which were formed into earth blocks. Mechanical tests were carried out for three different clays which showed that the polymer increased the mechanical resistance of the samples to varying degrees, depending on the plasticity index of each soil. Variation in soil grain size distributions and Atterberg limits were assessed and chemical compositions were studied and compared. X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and energy dispersive X-ray fluorescence (EDXRF) techniques were all used in conjunction with qualitative identification of the aggregates. Ultrasonic wave propagation was found to be a useful technique for assisting in the determination of soil shrinkage characteristics and fibre-soil adherence capacity and UPV results correlated well with the measured mechanical properties.

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