scholarly journals In vitro evaluation of physical vapor deposition coated beta titanium orthodontic archwires

2011 ◽  
Vol 82 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Vinod Krishnan ◽  
K. K. Ravikumar ◽  
K. Sukumaran ◽  
K. Jyothindra Kumar
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Testing Machine ◽  
Frictional Properties ◽  
Friction Testing ◽  
Beta Titanium ◽  
Low Load ◽  
Orthodontic Archwires ◽  
Deflection Rate

Abstract Objective: To determine in vitro the frictional properties, surface morphology, and load deflection rate with looped designs of two newly developed titanium aluminum nitride (TiAlN) and tungsten carbide/carbon (WC/C) physical vapor deposition (PVD) coated beta titanium orthodontic archwires coated with PVD. Materials and Methods: Frictional properties with Tidy's protocol, surface evaluation before and after friction testing with the help of scanning electron microscopy (ESEM), and load deflection rate with different orthodontic loops on Instron universal testing machine were evaluated. Results: The results clearly indicate reduced frictional properties for WC/C coated archwires when compared with uncoated and TiAlN coated archwires. There were no significant surface alterations upon ESEM evaluation of friction tested archwires. Low load deflection rate was exhibited by both coated archwires, the difference in load deflection rate between the coated and uncoated archwires was statistically significant. Conclusion: WC/C coated wires can be recommended for even sliding mechanics due to reduced frictional properties, better surface characteristics, and low load deflection rate compared with TiAlN coated and uncoated archwires.

scholarly journals Comparative Evaluation of Frictional forces between different Archwire-bracket Combinations

2014 ◽  
Vol 4 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Vinit Singh ◽  
Swati Acharya ◽  
Satyabrata Patnaik ◽  
Smruti Bhusan Nanda
Keyword(s):  
Stainless Steel ◽  
Tooth Movement ◽  
Testing Machine ◽  
Frictional Resistance ◽  
Nickel Titanium ◽  
Orthodontic Bracket ◽  
Fixed Appliance ◽  
Beta Titanium ◽  
Frictional Forces

Introduction: During sliding mechanics, frictional resistance is an important counterforce to orthodontic tooth movement; whichmust be controlled to allow application of light continuous forces.Objective: To investigate static and kinetic frictional resistance between three orthodontic brackets: ceramic, self-ligating, andstainless steel, and three 0.019×0.025” archwires: stainless steel, nickel-titanium, titanium-molybdenum.Materials & Method: The in vitro study compared the effects of stainless steel, nickel-titanium, and beta-titanium archwires onfrictional forces of three orthodontic bracket systems: ceramic, self-ligating, and stainless steel brackets. All brackets had 0.022”slots, and the wires were 0.019×0.025”. Friction was evaluated in a simulated half-arch fixed appliance on a testing machine. Thestatic and kinetic friction data were analyzed with 1-way analysis of variance (ANOVA) and post-hoc Duncan multiple rangetest.Result: Self-ligating (Damon) brackets generated significantly lower static and kinetic frictional forces than stainless steel (Gemini)and ceramic brackets (Clarity). Among the archwire materials, Beta-titanium showed the maximum amount of frictional forceand stainless steel archwires had the lowest frictional force.Conclusion: The static and kinetic frictional force for stainless steel bracket was lowest in every combination of wire.

scholarly journals Noble Metals for Modern Implant Materials: MOCVD of Film Structures and Cytotoxical, Antibacterial, and Histological Studies

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 851
Author(s):  
Svetlana I. Dorovskikh ◽  
Evgeniia S. Vikulova ◽  
Elena V. Chepeleva ◽  
Maria B. Vasilieva ◽  
Dmitriy A. Nasimov ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Noble Metals ◽  
Mononuclear Cells ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Ti Alloy ◽  
Peripheral Blood Mononuclear ◽  
Histological Studies

This work is aimed at developing the modification of the surface of medical implants with film materials based on noble metals in order to improve their biological characteristics. Gas-phase transportation methods were proposed to obtain such materials. To determine the effect of the material of the bottom layer of heterometallic structures, Ir, Pt, and PtIr coatings with a thickness of 1.4–1.5 μm were deposited by metal–organic chemical vapor deposition (MOCVD) on Ti6Al4V alloy discs. Two types of antibacterial components, namely, gold nanoparticles (AuNPs) and discontinuous Ag coatings, were deposited on the surface of these coatings. AuNPs (11–14 nm) were deposited by a pulsed MOCVD method, while Ag films (35–40 nm in thickness) were obtained by physical vapor deposition (PVD). The cytotoxic (24 h and 48 h, toward peripheral blood mononuclear cells (PBMCs)) and antibacterial (24 h) properties of monophase (Ag, Ir, Pt, and PtIr) and heterophase (Ag/Pt, Ag/Ir, Ag/PtIr, Au/Pt, Au/Ir, and Au/PtIr) film materials deposited on Ti-alloy samples were studied in vitro and compared with those of uncoated Ti-alloy samples. Studies of the cytokine production by PBMCs in response to incubation of the samples for 24 and 48 h and histological studies at 1 and 3 months after subcutaneous implantation in rats were also performed. Despite the comparable thickness of the fibrous capsule after 3 months, a faster completion of the active phase of encapsulation was observed for the coated implants compared to the Ti alloy analogs. For the Ag-containing samples, growth inhibition of S. epidermidis, S. aureus, Str. pyogenes, P. aeruginosa, and Ent. faecium was observed.

Effects of Load and Rotate Speed on the Friction of NBR by 45# Steel in Crude Oil Medium

2011 ◽  
Vol 230-232 ◽  
pp. 1079-1083
Author(s):  
Yi Zhang ◽  
Shi Jie Wang ◽  
Zhong Feng Guo ◽  
Zhong Wei Ren
Keyword(s):  
Friction Coefficient ◽  
Crude Oil ◽  
Constant Temperature ◽  
Testing Machine ◽  
Butadiene Rubber ◽  
Nitrile Butadiene Rubber ◽  
Friction Testing ◽  
Low Load ◽  
Test Result

Select two types of nitrile-butadiene rubber (NBR) which they are different in ingredients, under two types of crude oil medium respectively, the test is carried out on the friction testing machine. The test result shows that under the constant intermediate-low rotate speed and constant temperature, the friction coefficient decreases as the load increases; under the constant intermediate-low load and constant temperature, the friction coefficient increases as the rotate speed increases.

EFFECT OF COATING THICKNESS ON THE PROPERTIES OF TiN COATINGS DEPOSITED ON TOOL STEELS USING CATHODIC ARC PVD TECHNIQUE

2008 ◽  
Vol 15 (04) ◽  
pp. 401-410 ◽  
Author(s):  
A. MUBARAK ◽  
PARVEZ AKHTER ◽  
ESAH HAMZAH ◽  
MOHD RADZI HJ. MOHD TOFF ◽  
ISHTIAQ A. QAZI
Keyword(s):  
Surface Morphology ◽  
Tool Steel ◽  
Coating Thickness ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Testing Machine ◽  
High Speed Steel ◽  
Hard Coatings ◽  
Tool Steels ◽  
Cathodic Arc

Titanium nitride ( TiN ) widely used as hard coating material, was coated on tool steels, namely on high-speed steel (HSS) and D2 tool steel by physical vapor deposition method. The study concentrated on cathodic arc physical vapor deposition (CAPVD), a technique used for the deposition of hard coatings for tooling applications, and which has many advantages. The main drawback of this technique, however, is the formation of macrodroplets (MDs) during deposition, resulting in films with rougher morphology. Various standard characterization techniques and equipment, such as electron microscopy, atomic force microscopy, hardness testing machine, scratch tester, and pin-on-disc machine, were used to analyze and quantify the following properties and parameters: surface morphology, thickness, hardness, adhesion, and coefficient of friction (COF) of the deposited coatings. Surface morphology revealed that the MDs produced during the etching stage, protruded through the TiN film, resulting in film with deteriorated surface features. Both coating thickness and indentation loads influenced the hardness of the deposited coatings. The coatings deposited on HSS exhibit better adhesion compared to those on D2 tool steel. Standard deviation indicates that the coating deposited with thickness around 6.7 μm showed the most stable trend of COF versus sliding distance.

scholarly journals Effect of fluoride on mechanical properties of NiTi and CuNiTi orthodontic archwires: an in vitro study

2021 ◽  
Vol 26 (2) ◽  
Author(s):  
Pratap MANE ◽  
Chanamallappa R. GANIGER ◽  
Renuka PAWAR ◽  
Sandesh PHAPHE ◽  
Yusuf Ahammed RONAD ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Artificial Saliva ◽  
Testing Machine ◽  
In Vitro Study ◽  
Nickel Titanium ◽  
Orthodontic Wire ◽  
Point Bend ◽  
Orthodontic Archwires

ABSTRACT Introduction: After debonding, white spot may appear on the area below the bracket, which is the early clinical sign of carious lesion. There is increased caries risk underneath and adjacent to orthodontic bands and brackets, which call for maximum use of caries preventive procedures using various fluoride application methods. Objective: The aim of the study was to evaluate alterations in the mechanical properties (modulus of elasticity and yield strength) in loading and unloading phases for different orthodontic archwires (nickel-titanium [NiTi] and copper-nickel-titanium [CuNiTi]) when exposed routinely to fluoride prophylactic agents for a predetermined period of time. Methods: Preformed rectangular NiTi and CuNiTi wires were immersed in fluoride solution and artificial saliva (control) for 90 minutes at 37ºC. After immersion, specimens were tested using a 3-point bend test on a universal testing machine. Results: There is a significant reduction in the unloading yield strength when the NiTi and CuNiTi wires were exposed to APF gel. Conclusion: The result suggests that use of topical fluoride agents affect the mechanical properties of the wires, leading to increase in treatment duration. Fluoride prophylactic agents must be used with caution in patients undergoing orthodontic treatment. Injudicious use of these agents may cause corrosive effects on the orthodontic wire surfaces, with alteration in their mechanical properties.

scholarly journals Evaluation of the Friction of Self-Ligating and Conventional Bracket Systems

2011 ◽  
Vol 05 (03) ◽  
pp. 310-317 ◽  
Author(s):  
Simona Tecco ◽  
Donato Di Iorio ◽  
Riccardo Nucera ◽  
Beatrice Di Bisceglie ◽  
Giancarlo Cordasco ◽  
...  
Keyword(s):  
In Vitro Study ◽  
P Value ◽  
Low Friction ◽  
Experimental Conditions ◽  
Beta Titanium ◽  
Conventional Brackets ◽  
Orthodontic Archwires ◽  
Post Hoc ◽  
Conventional Bracket

ABSTRACTObjectives: This in vitro study evaluated the friction (F) generated by aligned stainless steel (SS) conventional brackets, self-ligating Damon MX© brackets (SDS Ormco, Glendora, California, USA), Time3© brackets (American Orthodontics, Sheboygan, Wisconsin, USA), Vision LP© brackets (American Orthodontics), and low-friction Slide© ligatures (Leone, Firenze, Italy) coupled with various SS, nickel-titanium (NiTi), and beta-titanium (TMA) archwires. Methods: All brackets had a 0.022-inch slot, and the orthodontic archwires were 0.014-inch, 0.016-inch, 0.014×0.025-inch, 0.018×0.025-inch, and 0.019×0.025-inch NiTi; 0.017×0.025-inch TMA; and 0.019×0.025-inch SS. Each bracket-archwire combination was tested 10 times. In the test, 10 brackets of the same group were mounted in alignment on a metal bar. The archwires moved through all the 10 brackets at a crosshead speed of 0.5 mm/min (each run lasted approximately 5 min). The differences among 5 groups of brackets were analyzed through the Kruskal-Wallis test, and a Mann-Whitney test was calculated as post hoc analysis. The P value was set at 0.05. Results: Coupled with 0.014-inch NiTi and 0.016-inch NiTi, Victory Series© brackets generated the greatest F, while Damon MX© and Vision LP© brackets generated the lowest (P<.05); no significant differences were observed between Time3© brackets and Slide© ligatures. Coupled with all the rectangular archwires, Victory Series© brackets, Slide© ligatures, and Vision LP© self-ligating brackets generated significantly lower F than did Time3© and Damon MX© self-ligating brackets (P<.05). Conclusions: These findings suggest that self-ligating brackets are a family of brackets that, in vitro, can generate different levels of F when coupled with thin or thick, rectangular, or round archwires. Clinical conclusions based on our results are not possible due to the limitations of the experimental conditions. (Eur J Dent 2011;5:310-317)

A New Model to Test Platelet Adhesion under Dynamic Conditions

1993 ◽  
Vol 16 (7) ◽  
pp. 545-550 ◽  
Author(s):  
I. Dion ◽  
C. Baquey ◽  
P. Havlik ◽  
J.R. Monties
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Platelet Adhesion ◽  
Construction Materials ◽  
Chemical Vapor ◽  
Ceramic Coatings ◽  
New Model ◽  
Systemic Error ◽  
The Difference

In order to evaluate under dynamic circumstances the in vitro platelet adhesion induced by rigid materials such as ceramic coatings deposited on selected substrates, a new model simulating a tube has been designed. In vitro platelet adhesion was assessed with this new model: the material was titanium nitride (TiN) deposited on Ti6A14V (TA6V) titanium alloy by a physical vapor deposition (PVD) process. The results were compared to those obtained with complete titanium carbide (TiC) graphite tubes coated with TiN by a chemical vapor deposition (CVD) process. The difference observed (less than 25%) in favour of the new system, could be due to the better surface state of the construction materials of this system. In fact it is a systemic error. However TiN confirms its good performance as a blood-contacting biomaterial.

Characterization and in vitro biocompatibility study of Ti–Si–N nanocomposite coatings developed by using physical vapor deposition

2014 ◽  
Vol 293 ◽  
pp. 143-150 ◽  
Author(s):  
Pramanshu Trivedi ◽  
Pallavi gupta ◽  
Swati Srivastava ◽  
R. Jayaganthan ◽  
Ramesh Chandra ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Nanocomposite Coatings ◽  
In Vitro Biocompatibility ◽  
Biocompatibility Study
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