Effect of Direct Electric Resistance Heat Treatment on Loading/Unloading Behavior of Nickel Titanium Orthodontic Wire

2014 ◽  
Vol 487 ◽  
pp. 135-140 ◽  
Author(s):  
Surachai Dechkunakorn ◽  
Chavarit Sujaritviriyakul ◽  
Niwat Anuwongnukroh ◽  
Nathaphon Tangit

Objective: The aim of this study was to investigate and compare the loading and unloading characteristics of various nickel-titanium (NiTi) and nickel-titanium-copper (NiTiCu) after direct electric resistance heat treatment method (Bender soarer-X equipment). Materials and Methods: Five types of commercial NiTi and NiTiCu orthodontic archwires [NiTi (W&H), NiTi (Ormco), CuNiTi (Ormco), Sentalloy (Tomy) and L&H (Tomy)] underwent heat treatment by the Bender soarer-X equipment and all samples underwent the three point bending tests to analyze their loading and unloading characteristics. Each type of wire was divided into 6 groups with 10 samples per group with one of the groups serving as non-heat treatment control group. The wire composition was analyzed by energy dispersive spectroscopy (EDS) method. Results: The results showed that the loading and unloading characteristics of W&H NiTi and Ormco NiTi after heat treatment were not significantly different from the non-heat treatment groups. But the Tomy Sentalloy, Tomy L&H and Ormco NiTiCu had significantly different results (p<0.05) after heat treatments. The factors which could affect the loading and unloading characteristics were the difference in alloy composition and the condition of heat treatment. Conclusion: Heat treatment increased the loading and unloading force of Tomy L&H and improved the shape forming ability of NiTi wire.

2014 ◽  
Vol 1025-1026 ◽  
pp. 330-335 ◽  
Author(s):  
Surachai Dechkunakorn ◽  
Niwat Anuwongnukroh ◽  
Nuntinee Nanthavannich ◽  
Subongkoch Tongkoom

Objectives: The aim of this study was to investigate and to compare the deactivation force, deactivation length and superelasticity in horizontal and vertical directions of Nickel-titanium (NiTi) orthodontic archwires made by 3 different manufactures. Materials and methods: The archwires tested were NiTi-OR (Ormco), NiTi-GH (G&H) and NiTi-H (Highland) and were 0.016 x 0.022 inch2in cross-section and 25 mm in length. The study analysed load-deflection curves from three-point bending tests performed for each type of NiTi wire in vertical (occluso-gingival) direction (0.022” in horizontal dimension) and horizontal (bucco-lingual) direction (0.016” in vertical dimension) at oral temperature (37±10oC). Statistical Analysis: Descriptive analysis and Kruskal Wallis test were performed to assess differences in deactivation force, deactivation length and superelasticity among the three brands. A p<0.05 was considered as significant. Results: The deactivation forces ranked from low to high were NiTi-GH, NiTi-OR and NiTi-H, 2.09, 2.57 and 2.90 N, respectively in horizontal dimension (occluso-gingival direction) and 3.04, 3.54 and 3.62 N in vertical dimension (bucco-lingual direction), respectively. For the deactivation length, ranking from long to short were NiTi-GH, NiTi-OR and NiTi-H, 1.08, 1.02 and 0.63 mm in horizontal dimension and 1.63, 1.46 and 1.13 mm in vertical dimension, respectively. In regards to superelasticity, NiTi-OR showed the highest superelasticity, 15.37 in horizontal and 9.68 in vertical dimension, followed by NiTi-GH, 9.51 for horizontal and 6.40 for vertical dimension and NiTi-H, 4.12 for horizontal dimension and 2.96 for vertical dimension. Conclusion: Deactivation force was higher in vertical than horizontal dimension and deactivation length was longer in vertical than horizontal dimension. However, the superelasticity was higher in horizontal than vertical dimension, except NiTi-H. The high priced NiTi wire (NiTi-OR) had the most superelasticity following by medium (NiTi-GH) and low priced wires (NiTi H).


2019 ◽  
Vol 3 (4) ◽  
Author(s):  
Xiaoxu Shi ◽  
Lanying Qin ◽  
Jun Peng ◽  
Zishen Zhao ◽  
Haixiang Zhang

Objective: To investigate the clinical efficacy of plasma exchange therapy for autoimmune bullous skin disease. METHODS: Fifty patients with autoimmune bullous skin disease enrolled in our hospital from January 2018 to January 2019 were selected. The patients were grouped by treatment method: 25 control group patients were given conventional hormone therapy, while 25 experimental group patients were treated with plasma exchange therapy; efficacy of treatment was compared between two groups of patients. RESULTS: Initial dose, maximum dose, and cumulative dose of glucocorticoids were lower in experimental group patients than those in control group (P<0.05). Incidence of complication was lower in experimental group patients than those in control group (P<0.05); the difference was significant. There was no significant difference in short-term efficacy between the two groups (P>0.05). Conclusion: The application of plasma exchange therapy was effective for treatment of autoimmune bullous skin disease. It could reduce dosage amount of glucocorticoids and incidence of complications; its application can be promoted.


2017 ◽  
Vol 266 ◽  
pp. 245-251 ◽  
Author(s):  
Kanuengnit Pongpat ◽  
Surachai Dechkunakorn ◽  
Niwat Anuwongnukroh ◽  
Anak Khantachawana

Curved nickel-titanium (NiTi) orthodontic archwires are widely used in deep bite and open bite correction because of their extraordinary properties of shape memory and superelasticity. The aim of this study were to investigate the mechanical properties of curved NiTi archwires prepared by two different techniques; cold bending and direct electric resistance heat treatment (DERHT) bending and compare those properties to preformed curve NiTi archwires. Preformed curve archwires, 0.016x0.022 inch, were served as a control (group1). Plain archwires were curved into similar geometry as control by fingers (group2) and under the application of DERHT (group3). The three-point bending test was performed to analyze unloading force, springback and stiffness of archwires. Surface hardness was measured by Vickers micro-hardness test. The result showed that the unload force of all sample groups were similar. However, the stiffness and spring back properties of group2 and group3 were significantly higher than those of group 1(p<0.05). Moreover, surface hardness of cold forming technique and preform-curved NiTi archwire was slightly lower than those obtained from DERHT bending technique. Based on these results, the cold bending technique could provide the curved archwire with similar mechanical properties to the preform-curved NiTi archwire. Therefore, the cold bending technique was acceptable to be used as a chair-side orthodontic NiTi wire bending.


2016 ◽  
Vol 21 (1) ◽  
pp. 83-88
Author(s):  
Marcelo Faria da Silva ◽  
Célia Regina Maia Pinzan-Vercelino ◽  
Júlio de Araújo Gurgel

Objective: The aim of this in vitro study was to evaluate the deflection-force behavior of nickel-titanium (NiTi) orthodontic wires adjacent to the portion submitted to heat treatment. Material and Methods: A total of 106 segments of NiTi wires (0.019 x 0.025-in) and heat-activated NiTi wires (0.016 x 0.022-in) from four commercial brands were tested. The segments were obtained from 80 archwires. For the experimental group, the distal portion of each segmented archwire was subjected to heat treatment (n = 40), while the other distal portion of the same archwire was used as a heating-free control group (n = 40). Deflection tests were performed in a temperature-controlled universal testing machine. Unpaired Student's t-tests were applied to determine if there were differences between the experimental and control groups for each commercial brand and size of wire. Statistical significance was set at p < 0.05. Results: There were no statistically significant differences between the tested groups with the same size and brand of wire. Conclusions: Heat treatment applied to the distal ends of rectangular NiTi archwires does not permanently change the elastic properties of the adjacent portions.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1774.1-1775
Author(s):  
A. Keskin ◽  
B. Basakci Calik ◽  
E. Gur Kabul ◽  
V. Cobankara

Background:Fibromyalgia (FM) is a systemic rheumatic disease characterized by diffuse pain in the body, tenderness, fatigue and many more symptoms. Exercise is effective and safe method in individuals with FM. Connective tissue massage, another treatment method, is a reflex therapy where shear force is applied in a certain order at the connective tissue interfaces of the skin. In the literature, there is limited study releted compared with clinical pilates exercises and connective tissue massage in individuals with FM.Objectives:The aim of the study was to examine the effectiveness of clinical pilates exercises and connective tissue massage in Individuals with Fibromyalgia on disease activity, number of painful regions, anxiety, biopsychosocial status and quality of life.Methods:32 women (age mean=52.43±8.32) diagnosed with FM according to American College of Rheumatology (ACR) criteria were included in this study. Participants were randomly divided into two groups as interventional group (n=15, mean age=48.80±7.48) and control group (n=17, mean age=55.64±7.87). While the connective tissue massage and clinical pilates exercises were applied to the treatment group, only clinical pilates exercises were applied to the control group. After the demographic characteristics and disease related data of the individuals were recorded; number of painful regions were assessed with Pain Location Inventory (PLI), disease impact with Fibromyalgia Impact Questionnare (FIQ), functional status with Health Assessment Questionnare (HAQ), anxiety with Beck Anxiety Inventory (BAI), quality of life with Short Form-36 (SF-36) and biopsychosocial status with Cognitive Exercise Therapy Approach (BETY) Scale were evaluated. All evaluations were made before and after treatment. All interventions were applied 3 days per week for 6 weeks by the same experienced physical therapist. One session for clinical pilates exercises consisted of 60 minutes (10 minutes warm up, 40 minutes clinical pilates exercises, 10 minutes cool-down). Connective tissue massage was started from lumbosacral region and continued lower thoracic, scapular, interscapular, and cervical regions, respectively. The Kolmogorov-Smirnov Test was used to determine whether the continuous variables were normal distributions.Results:When the pre-treatment and post-treatment results are analyzed; the results were significant in the intervention group of PLI (p = 0.007), SF 36 physical component (p = 0.025) and mental component (p = 0.017) and FIQ (p = 0.004), while in the control group the difference in SF 36 physical component (p = 0.008) and mental component (p = 0.024), FIQ (p = 0.001) and BAI (p = 0.043) was significant. Delta values were calculated by subtracting post-treatment results from pre-treatment results. When the delta values of the groups are compared, it was determined that the difference only in the PLI (p = 0.023) were significant in favor of the treatment group.Conclusion:According to our results, connective tissue massage has been shown to be effective in reducing the number of painful areas in addition to the positive effects of clinical pilates exercises in individuals with FM. In order to increase the effectiveness of treatment in individuals with FM, we recommend the use of connective tissue massage as an additional treatment method.References:[1]Busch, Angela J., et al. Exercise therapy for fibromyalgia. Current pain and headache reports 2011;15: 358.[2]Burckhardt CS. Nonpharmacologic management strategies in fibromyalgia. Rheumatic diseases clinics of North America, 2002, 28(2),291-304.Disclosure of Interests:None declared


2021 ◽  
Vol 26 (2) ◽  
Author(s):  
Pratap MANE ◽  
Chanamallappa R. GANIGER ◽  
Renuka PAWAR ◽  
Sandesh PHAPHE ◽  
Yusuf Ahammed RONAD ◽  
...  

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.


2008 ◽  
Vol 55-57 ◽  
pp. 249-252 ◽  
Author(s):  
W. Kiattiwongse ◽  
Anak Khantachawana ◽  
P. Santiwong

Two types of rectangular orthodontic archwires; NiTiTM and 40oCuNiTi, were heat treated by Direct Electric Resistance Heat Treatment (DERHT) using different electric currents for 4 s. Their mechanical properties were then evaluated by micro hardness and three-point bending tests. After applying 4.5-5.5 A current, the hardness of NiTiTM increased with the increased current, whereas the change in hardness of 40oCuNiTi was slight. When 6 A current was applied, the hardness of the midspan of both wires significantly decreased. From the three-point bending test, unloading forces of NiTiTM increased after treating with 5.5 A current, while those of 40oCuNiTi decreased. However, both specimens lost their superelasticity when applied with 6 A current. In conclusion, after DERHT, various changes in mechanical properties can be noted in the different types of nickel titanium archwire.


2019 ◽  
Vol 4 (3) ◽  
pp. 142
Author(s):  
Harris Gadih Pratomo ◽  
Endah Mardiati ◽  
Eky Soeria Soemantri ◽  
Ida Ayu Evangelina

The development of technology in orthodontic field produces some orthodontic wires that have different deflection abilities. Loading force is the force needed to place an orthodontic wire in bracket slot (activation). Unloading force is the force produced by an orthodontic wire to move tooth (deactivation). Deflection test with three-point bending technique is a technique that is often used to determine the magnitude of the activation and deactivation force of orthodontic wire. Stainless steel (SS), nickel titanium (NiTi), copper nickel titanium (CuNiTi), and beta titanium (TMA), are the types of frequently used wires. This study aimed to compare loading and unloading force on the deflection test of SS, NiTi, CuNiTi, and TMA orthodontic wires sized 0.016 x 0.022 inch on the load-deflection graph. This is a laboratoryexperimental research on a total of 16 pieces of SS, NiTi, CuNiTi, and TMA orthodontic wires sized 0.016 x 0.022 inches. The group was divided based on the type of material. The deflection test was performed using a universal testing machine with a press speed of 5 mm/minute. Loading and unloading forces were recorded on deflections of 0.5; 1; and1.5 mm. Statistical tests of differences among groups were carried out by ANOVA analysis (p-value ≤ 0.05) and post-hoc analysis with T-test. There were significant differences in the loading and unloading forces recorded on deflections of 0.5; 1; and 1.5 mm; except for deflections of 0.5 mm of the SS and nickel-titanium wires. The wire deflection force fromthe lowest to the highest was CuNiTi wire, nickel-titanium wire, TMA wire, and stainless-steel wire.


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