Ultrastructural effect of self-ligating bracket materials on stainless steel and superelastic niTi wire surfaces

2012 ◽  
Vol 75 (8) ◽  
pp. 1076-1083 ◽  
Author(s):  
Samjin Choi ◽  
Sunghoon Lee ◽  
Youjin Cheong ◽  
Ki-Ho Park ◽  
Hun-Kuk Park ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Niti Wire ◽  
Ultrastructural Effect

Comparison of Chemical Properties and Ni Release of Stainless Steel and Nickel Titanium Wires

2014 ◽  
Vol 884-885 ◽  
pp. 560-565 ◽  
Author(s):  
Wassana Wichai ◽  
Niwat Anuwongnukroh ◽  
Surachai Dechkunakorn
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Artificial Saliva ◽  
Steel Wire ◽  
Nickel Titanium ◽  
The Other ◽  
Stainless Steel Wire ◽  
Niti Wire ◽  
Titanium Wire ◽  
Niti Wires

Objective: This study aimed to determine the composition and corrosion resistance of stainless steel and nickel titanium (NiTi) archwires and to compare Ni released from simulated standard fixed orthodontic appliances ligated with stainless steel and NiTi wires in artificial saliva at pH 5.14 and pH 6.69. in 4 weeks at 37oC. Materials and Method: Two commercial rectangular wires, 0.016 x 0.022 in size were studied, one Ormco stainless steel wire and another Ormco nickel titanium wire. Their composition was analyzed by an energy disporsive X-ray spectrometer (ESC) and their corrosion resistance was evaluated by a potentiodynamic polarization technique. For Ni release, the twenty-eight simulated fixed appliance sample sets were used, each corresponding to one half-maxillary arch. The samples were divided in 2 groups (14 sets per group). The first one was ligated to Ormco stainless steel archwires and the other one to Ormco NiTi archwires with elastomeric ligatures. Half sets of each group were immersed in 50 ml artificial saliva at pH 5.14 and the other half were immersed at pH 6.69. Ni release was quantified using flame atomic absorption spectrophotometry. Statistical analysis of variance (t-test) was determined on days 1, 4, 7, 9, 14, 21 and 28 comparing the amount of Ni released between groups. Results: Stainless steel wire was composed of Ni, Cr, Si, Mn and Fe while the nickel titanium wire was composed of Ti, Ni and Cr. NiTi wire has more percentage of Ni and therefore has less corrosion resistance than stainless steel wire. For Ni release, stainless steel and NiTi continuously increased at the time intervals for both pH levels. For group one, stainless steel wire had more Ni release at pH 5.14 and for the other group, NiTi wire had more Ni-release at pH 6.69. At 4 weeks, the Ni release of one half-maxillary arch was 1.383 ppm (1383 μg/l) at pH 5.14 and 1.079 ppm (1078 μg/l) at pH 6.69 for stainless steel wire while it was 1.221 ppm (1221 μg/l) at pH 5.14 and 1.267 ppm (1267μg/l) at pH 6.69 for NiTi wire. No significant difference was found in the amount of Ni release from stainless steel and NiTi wires at pH 5.14 and pH 6.69 in the different time intervals except on day 1 wherein the stainless steel archwire was significantly different (p<0.05) at pH 5.14 and pH 6.69. Conclusions: The NiTi wire had more Ni contain and less corrosion resistance than stainless steel wire. Stainless steel had more Ni release at pH 5.14 than pH 6.69 but NiTi had greater Ni release at pH 6.69 than pH 5.14.

scholarly journals Mechanical properties of orthodontic wires on ceramic brackets associated with low friction ligatures

2017 ◽  
Vol 46 (3) ◽  
pp. 125-130
Author(s):  
Fernando KOIKE ◽  
Hiroshi MARUO ◽  
Rogério LACERDA-SANTOS ◽  
Matheus Melo PITHON ◽  
Orlando Motohiro TANAKA
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Mechanical Test ◽  
Steel Wire ◽  
Nickel Titanium ◽  
Bending Test ◽  
Test Machine ◽  
Orthodontic Wires ◽  
Niti Wire ◽  
Ceramic Brackets

Abstract Introduction Few studies investigated the mechanical properties of orthodontic wires on ceramic brackets associated the ligatures. Objective This study aimed to compare the load-deflection of orthodontic wires with round section of 0.016” made of stainless steel (SS), nickel-titanium (NiTi) and glass fiber-reinforced polymer composite (GFRPC). Material and method Sixty specimens obtained from 10 sectioned pre-contoured arches (TP Orthodontics), were divided into 3 groups of 20 according to each type of material (1 esthetic-type wire and 2 not esthetic) and length of 50 mm. The methodology consisted of a 3-point bending test using esthetic ceramic brackets (INVU, TP Orthodontics, Edgewise, 0.022”x 0.025”) as points of support. The tensile tests were performed on a mechanical test machine, at a speed of 10 mm/min, deflection of 1 mm, 2 mm and 3 mm. Friedman’s Non Parametric Multiple comparisons test was used (P<0.05). Result The nickel-titanium wire presented smaller load/ deflection compared with stainless steel. GFRPC wires had lower strength values among all groups evaluated (P<.05). The steel wire showed permanent deformation after 3 mm deflection, NiTi wire demonstrated memory effect and the esthetic type had fractures with loss of strength. Conclusion It can be concluded that steel wires have high strength values, requiring the incorporation of loops and folds to reduce the load / deflection. NiTi and GFRPC wires produced low levels of force, however the esthetic wire was shown to fracture and break.

FRICTION OF STAINLESS STEEL, NICKEL-TITANIUM ALLOY, AND BETA-TITANIUM ALLOY ARCHWIRES IN TWO COMMONLY USED ORTHODONTIC BRACKETS

2011 ◽  
Vol 11 (04) ◽  
pp. 917-928 ◽  
Author(s):  
JIAN-HONG YU ◽  
HENG-LI HUANG ◽  
LI-CHUN WU ◽  
JUI-TING HSU ◽  
YIN-YU CHANG ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Titanium Alloy ◽  
Frictional Force ◽  
Steel Wire ◽  
Nickel Titanium ◽  
The Self ◽  
Stainless Steel Wire ◽  
Niti Wire ◽  
Beta Titanium ◽  
Frictional Forces

In orthodontic treatment, the efficiency of tooth movement is affected by the frictional force between the archwire and bracket slot. This study evaluated the static and kinetic frictional forces produced in different combinations of orthodontic archwires and brackets. Three types of archwires [stainless steel, nickel-titanium (NiTi) alloy, and beta-titanium (TMA) alloy] and two types of brackets (stainless steel and self-ligating) were tested. Both static and kinetic frictional forces of each archwire–bracket combination were measured 25 times using a custom-designed apparatus. The surface topography and hardness of the archwires were also evaluated. All data were statistically analyzed using two-way analysis of variance and Tukey's test. The experiments indicated that the static frictional force was significantly higher than the kinetic frictional force in all archwire–bracket combinations not involving TMA wire. TMA wire had the highest friction, followed by NiTi wire, and then stainless steel wire when using the stainless steel bracket. However, there was no difference between NiTi and stainless steel archwires when using the self-ligating bracket. For TMA wire, the friction was higher when using the stainless steel bracket than when using the self-ligating bracket. Scanning electron microscopy indicated that stainless steel wire exhibited the smoothest surface topography. The hardness decreased in the order of stainless steel wire > TMA wire > NiTi wire. This study demonstrates that the frictional forces of brackets are influenced by different combinations of bracket and archwire. The reported data will be useful to orthodontists.

scholarly journals Comparison of Nickel and Chromium Ions Released from Stainless Steel and NiTi Wires after Immersion in Oral B®, Orthokin® and Artificial Saliva

2014 ◽  
Vol 15 (4) ◽  
pp. 403-406 ◽  
Author(s):  
Abdolreza Jamilian ◽  
Omid Moghaddas ◽  
Shabnam Toopchi ◽  
Letizia Perillo
Keyword(s):  
Stainless Steel ◽  
Artificial Saliva ◽  
Three Solutions ◽  
Orthodontic Wires ◽  
Time Intervals ◽  
Niti Wire ◽  
Nickel Ions ◽  
Chromium Ions ◽  
All Solutions ◽  
Niti Wires

ABSTRACT Aim Oral environment of the mouth is a suitable place for biodegradation of alloys used in orthodontic wires. The toxicity of these alloys namely nickel and chromium has concerned the researchers about the release of these ions from orthodontic wires and brackets. The aim of this study was to measure the levels of nickel and chromium ions released from 0.018” stainless steel (SS) and NiTi wires after immersion in three solutions. Materials and methods One hundred and forty-four round NiTi and 144 round SS archwires with the diameters of 0.018” were immersed in Oral B®, Orthokin® and artificial saliva. The amounts of nickel and chromium ions released were measured after 1, 6, 24 hours and 7 days. Results Two way repeated ANOVA showed that the amount of chromium and nickel significantly increased in all solutions during all time intervals (p < 0.002). Conclusion Chromium and nickel ions were released more in NiTi wire in all solutions compared with SS wire. The lowest increase rate was also seen in artificial saliva. Clinical significance There is general consensus in literature that even very little amounts of nickel and chromium are dangerous for human body specially when absorbed orally; therefore, knowing the precise amount of these ions released from different wires when immersed in different mouthwashes is of high priority. How to cite this article Jamilian A, Moghaddas O, Toopchi S, Perillo L. Comparison of Nickel and Chromium Ions Released from Stainless Steel and NiTi Wires after Immersion in Oral B®, Orthokin® and Artificial Saliva. J Contemp Dent Pract 2014; 15(4):403-406.

In vitro Evaluation of Static Frictional Forces at the Bracket-archwire Interface

2019 ◽  
Vol 70 (4) ◽  
pp. 1192-1196
Author(s):  
Anca-Oana Dragomirescu ◽  
Ciprian-Ion Rizescu ◽  
Ana-Maria Mihai ◽  
Angelica Bencze ◽  
Elina Teodorescu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Testing Machine ◽  
Traction Force ◽  
Niti Wire ◽  
Polycrystalline Alumina ◽  
Test Conditions ◽  
Polycrystalline Ceramic ◽  
Ceramic Brackets ◽  
Frictional Forces

The aim of this research is to compare the static frictional forces generated by different bracket-archwire couples. The study group consisted of three types of ceramic brackets (polycrystalline alumina with stainless steel slot, polycrystalline alumina and monocrystalline alumina), one stainless steel bracket and two types of archwires (0.016` NiTi and 0.019x0.025` SS). Brackets corresponding to the upper right quadrant (form upper right central incisor to the upper right second premolar) were bonded on standardized maxillary models and elastomeric ligatures were used to secure the archwire to the bracket system. An in-vitro experiment was conducted using a testing machine designed to measure the compression and traction force, both in dry and wet testing conditions. The results indicated statistically significant differences between most bracket-archwire groups. According to the data obtained, stainless steel brackets produced the lowest static frictional forces, regardless of test conditions and orthodontic archwire type. Polycrystalline ceramic brackets with stainless steel slot generated higher static frictional forces than stainless steel brackets, but lower than ceramic brackets when combined with the 0.019`�0.025` SS archwire. No significant differences were found between polycrystalline and monocrystalline ceramic brackets. Experiments performed with 0.019�0.025` SS archwire produced greater static frictional forces than those with 0.016` NiTi wire. Static frictional forces were not significantly influenced by the test conditions.

NiAl precipitation in Fe-12w/o Cr-5w/o Ni-4w/o Al

1983 ◽  
Vol 41 ◽  
pp. 202-203
Author(s):  
L.E. Murr ◽  
J.S. Dunning ◽  
S. Shankar
Keyword(s):  
Solid Solution ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Alloy Composition ◽  
Chromium Content ◽  
Scale Up ◽  
Optical Metallography ◽  
Property Evaluation ◽  
310 Stainless Steel ◽  
Microstructural Studies

Aluminum additions to conventional 18Cr-8Ni austenitic stainless steel compositions impart excellent resistance to high sulfur environments. However, problems are typically encountered with aluminum additions above about 1% due to embrittlement caused by aluminum in solid solution and the precipitation of NiAl. Consequently, little use has been made of aluminum alloy additions to stainless steels for use in sulfur or H2S environments in the chemical industry, energy conversion or generation, and mineral processing, for example.A research program at the Albany Research Center has concentrated on the development of a wrought alloy composition with as low a chromium content as possible, with the idea of developing a low-chromium substitute for 310 stainless steel (25Cr-20Ni) which is often used in high-sulfur environments. On the basis of workability and microstructural studies involving optical metallography on 100g button ingots soaked at 700°C and air-cooled, a low-alloy composition Fe-12Cr-5Ni-4Al (in wt %) was selected for scale up and property evaluation.

Comparison of Recovery and Recrystallization in Stainless Steel Following Plane-Wave Shock Loading and Explosive Forming

1970 ◽  
Vol 28 ◽  
pp. 428-429 ◽  
Author(s):  
J. A. Korbonski ◽  
L. E. Murr
Keyword(s):  
Stainless Steel ◽  
Shock Loading ◽  
Pressure Pulse ◽  
Shock Pressure ◽  
304 Stainless Steel ◽  
Strain Rates ◽  
Two Dimensional ◽  
Aisi 304 Stainless Steel ◽  
Aisi 304 ◽  
Explosive Forming

Comparison of recovery rates in materials deformed by a unidimensional and two dimensional strains at strain rates in excess of 104 sec.−1 was performed on AISI 304 Stainless Steel. A number of unidirectionally strained foil samples were deformed by shock waves at graduated pressure levels as described by Murr and Grace. The two dimensionally strained foil samples were obtained from radially expanded cylinders by a constant shock pressure pulse and graduated strain as described by Foitz, et al.

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