Comparison of Loading and Unloading Behavior of Commercial and Locally Made Copper-Nickle-Titanium (NiTiCu) Orthodontic Archwire

2013 ◽  
Vol 746 ◽  
pp. 308-314
Author(s):  
V. Puranitee ◽  
Surachai Dechkunakorn ◽  
N. Anuwongnukroh ◽  
A. Khantachawana ◽  
A. Phukaoluan
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Testing Machine ◽  
Bending Test ◽  
Stress Plateau ◽  
Percentage Recovery ◽  
Significant Difference ◽  
Loading And Unloading ◽  
Materials Used ◽  
Stress Hysteresis

Background: Copper-nickel-titanium (NiTiCu) archwire has been favoured in clinical orthodontic practice because of its superior superelasticity (SE) and shape memory effect (SME) properties. Objective: To compare the loading and unloading behavior of commercial NiTiCu orthodontic archwire and locally made NiTiCu orthodontic archwire based on composition and mechanical properties especially in relation to percentage recovery, stress plateau, stress hysteresis, and loading and unloading slope. Materials and Methods: The materials used were divided into two categories: the NiTiCu (40°C) commercial Ormco brand (USA) archwires and the locally made NiTiCu archwires produced at King Mongkut University of Technology Thonburi (KMUTT). The samples were examined using an Electron Probe Microanalysis (EPMA) to test their chemical composition. For loading and unloading behavior the Universal Testing Machine (Instron) was used for the three-point bending test. The Mann-Whitney U test was employed to analyze and compare the data. Results: Chemical composition, there were significant differences in at.% of Ni, Ti, and Cr composition between commercial and locally made archwire. There was no significant difference in at.% in Cu. In terms of percentage recovery, there was a significant decrease in locally made archwire. For stress plateau and stress hysteresis, there were also significant increases in Thai-made archwire when compared with commercial archwires. In addition NiTiCu (Ormco) showed significantly less inclination than locally made NiTiCu archwire in both loading and unloading slopes. Conclusion: Based on the results of this study, the mechanical properties of the locally made archwires were not as suitable as the commercial archwires. This preliminary study provides useful information for the further development of locally made NiTiCu archwires. Therefore, the use of the NiTiCu should be considered on a case by case basis. This experiment was useful in comparing locally made NiTiCu wire and commercial orthodontic wire.

scholarly journals Influence of Concentrations of Methacrylate and Acrylate Monomers on the Properties of Fiber Reinforced Polymethyl Methacrylate Denture Base Materials

2018 ◽  
Vol 26 (2) ◽  
pp. 329-350 ◽  
Author(s):  
Faik Tugut ◽  
Mehmet Turgut ◽  
Dursun Saraydin
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Testing Machine ◽  
Weight Ratio ◽  
Acrylic Resin ◽  
Bending Test ◽  
Control Group ◽  
Test Machine ◽  
Fiber Reinforced ◽  
Significant Difference

Abstract The study aimed to evaluate the effects of adding different concentrations of 2 hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), ethyl methacrylate (EA) and isobutyl methacrylate (IBMA) monomers on the structural, thermal and mechanical properties of a fiber reinforced heat-polymerized acrylic resin. For each test, 126 acrylic resin specimens were fabricated and divided into 6 groups with 7 specimens each. One group was the control group, the other one is a fiber reinforced group and others were the test groups, which were formed according to the different concentrations of monomers. 6 mm length, and the weight ratio of 3% short glass fibers are added to acrylic powder polymerized by heating. The 2%, 5%, 10%, at 20 % ratios of different comonomers added to a monomer of MMA are composed of copolymer structures. Flexural strength was assessed with a three-point bending test using a universal testing machine. Impact strength testing was conducted using an impact test machine by the Charpy method. The analysis of the connection between acrylic resin and fiber by SEM and structural changes in the acrylic resin was investigated by FTIR spectroscopy. Data analyses using analysis of Kruskal-Wallis and Mann-Whitney U tests (α=0.05) significant difference tests showed that adding 2%, 5% HEMA and IBMA monomers significantly increased the flexural and impact strength compared to the control, only fiber and others group (P< 0.05). It is observed that the process of adding low concentration of HEMA and IBMA monomers improved certain mechanical properties of fiber reinforced with polymethylmethacrylate.

scholarly journals Effect of Preheating on the Mechanical Properties of Resin Composites

2008 ◽  
Vol 02 (04) ◽  
pp. 263-268 ◽  
Author(s):  
Mine Betül Uctasli ◽  
Hacer Deniz Arisu ◽  
Lippo VJ Lasilla ◽  
Pekka K Valittu
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Testing Machine ◽  
Bending Test ◽  
Resin Composites ◽  
Three Point Bending ◽  
Commercial Resin ◽  
Significant Difference ◽  
Light Curing ◽  
Post Hoc

ABSTRACTObjectives: The purpose of this study was to compare the flexural strength and modulus of two commercial resin composites, at room temperature and 40, 45 and 50�C prior to light polymerization with standard and step-cure protocols.Methods: One nanohybrid (Grandio, VOCO, Cuxhaven, Germany), and microhybrid compositeresin (Filtek Z250, 3M ESPE, St. Paul, MN, USA) were used. The materials were inserted into rectangular moulds at room temperature or preheated to a temperature of 40, 45 or 50°C and cured with standard or step-cure protocols with high intensity halogen (Elipar Highlight, 3M-ESPE, St. Paul, MN, USA). Ten specimens were prepared for each preheating and light curing protocol. A three-point bending test was performed using a universal testing machine at a crosshead speed of 1 mm/min. The data were analyzed by one-way analysis of variance and Tukey’s post hoc tests (P<.05) to examine the effect of curing protocol and preheating. Pearson’s correlation test was used to determine the correlation between tested mechanical properties and preheating.Results: There were no statistically significant difference between tested mechanical properties of the materials, curing protocols and temperature of the materials. No significant correlation was found between preheating and tested mechanical properties.Conclusions: The mechanical properties of the tested materials did not changed by preheating so the tested materials could be preheated because of the other potential clinical advantages like more adaptation to the cavity walls. (Eur J Dent 2008;2:263-268)

Bending Properties of General Purpose Stainless Steel Wire Formed for Orthodontic Use

2013 ◽  
Vol 746 ◽  
pp. 394-399
Author(s):  
Niwat Anuwongnukroh ◽  
Yosdhorn Chuankrerkkul ◽  
Surachai Dechkunakorn ◽  
Pornkiat Churnjitapirom ◽  
Theeralaksna Suddhasthira
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Orthodontic Treatment ◽  
Steel Wire ◽  
General Purpose ◽  
Stainless Steel Wire ◽  
Bending Test ◽  
Bending Properties ◽  
Steel Wires ◽  
Significant Difference

The archwire is generally used in fixed appliances for orthodontic treatment to correct dental malocclusion. However, it is interesting to know whether general purpose stainless steel wire could replace commercial orthodontic archwire in orthodontic practice for economic reasons. The purpose of this study was to determine the bending properties of general purpose stainless steel wire compared with commercial orthodontic stainless steel wires after forming as an archwire for orthodontic use. The samples used in this study were 90 general purpose and 45 commercial (Highland) round stainless steel wires in 0.016, 0.018, and 0.020 sizes (30 general purpose and 15 commercial wires for each size). All 15 general purpose stainless steel wires with different sizes were formed into orthodontic archwire with a Universal Testing Machine. All samples were tested (three-point bending test) for mechanical properties. The results showed no significant difference between general purpose and commercial orthodontic wires in size 0.016 for 0.1 mm offset bending force, 0.2% yield strength, and springback. Although many mechanical properties of general purpose wires differed from commercial wires, their values conformed to other previous studies within the range of clinical acceptance. In conclusion, orthodontic formed general purpose round stainless steel wires had statistically different (p <0.05) mechanical properties from commercial orthodontic stainless steel wires (Highland) but the mechanical properties were acceptable to use in orthodontic treatment.

scholarly journals Effect of Gamma Radiation and Endodontic Treatment on Mechanical Properties of Human and Bovine Root Dentin

2016 ◽  
Vol 27 (6) ◽  
pp. 670-674 ◽  
Author(s):  
Veridiana Resende Novais ◽  
Priscilla Barbosa Ferreira Soares ◽  
Carlla Martins Guimarães ◽  
Laís Rani Sales Oliveira Schliebe ◽  
Stella Sueli Lourenço Braga ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Gamma Radiation ◽  
Hardness Test ◽  
Knoop Hardness ◽  
Endodontic Treatment ◽  
Bending Test ◽  
Human Teeth ◽  
Significant Difference ◽  
Root Dentin

Abstract This study evaluated the effect of gamma radiation and endodontic treatment on the microhardness and flexural strength of human and bovine root dentin. Forty single-rooted human teeth and forty bovine incisor teeth were collected, cleaned and stored in distilled water at 4 °C. The human and bovine teeth were divided into 4 groups (n=10) resulting from the combination of two study factors: first, regarding the endodontic treatment in 2 levels: with or without endodontic treatment; and second, radiotherapy in two levels: with or without radiotherapy by 60 Gy of Co-60 gamma radiation fractioned into 2 Gy daily doses five days per week. Each tooth was longitudinally sectioned in two parts; one-half was used for the three-point bending test and the other for the Knoop hardness test (KHN). Data were analyzed by 3-way ANOVA and Tukey HSD test (α=0.05). No significant difference was found for flexural strength values. The human dentin had significantly higher KHN than the bovine. The endodontic treatment and radiotherapy resulted in significantly lower KHN irrespective of tooth origin. The results indicated that the radiotherapy had deleterious effects on the microhardness of human and bovine dentin and this effect is increased by the interaction with endodontic therapy. The endodontic treatment adds additional negative effect on the mechanical properties of radiated tooth dentin; the restorative protocols should be designed taking into account this effect.

Novel Approach for Tension Testing Micro Tubes

2018 ◽  
Author(s):  
Scott W. Wagner ◽  
William J. Emblom ◽  
Kevin M. Johnson ◽  
Kahaan P. Shah ◽  
Navrose Handa ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Predictive Models ◽  
Testing Machine ◽  
Tube Hydroforming ◽  
Novel Approach ◽  
New Process ◽  
Tension Testing ◽  
Materials Used ◽  
Book Values

Due to the miniaturization of products, new or modified processes are required to create small components. With the development of these new processes, it is also important to establish methods to evaluate the mechanical properties of the materials used in these components. These properties are necessary for accurately creating representative predictive models and simulations. At the same time, this evaluation can be challenging as sampling specimens become smaller the securing and handling of these smaller specimens becomes very difficult. Recently, researchers made studies to develop and model the micro tube hydroforming (MTHF) process. In many of these studies, the mechanical properties used were either traditional book values or were values obtained directly from the manufacturers. The question then becomes, how do the manufacturers determine their provided mechanical properties? The research in this study focuses on the development and testing of a new process to determine the mechanical properties of stainless steel micro tubes. Specifically, a set of clamps for securing a micro tube in a standard tension-testing machine were developed. A method for localizing the stress within the middle of a specimen was developed and the findings are presented in this paper.

scholarly journals Can extended photoactivation time of resin-based fissure sealer materials improve ultimate tensile strength and decrease water sorption/solubility?

2012 ◽  
Vol 06 (04) ◽  
pp. 402-407
Author(s):  
Boniek Castillo Dutra Borges ◽  
Eduardo José Souza-Júnior ◽  
Anderson Catelan ◽  
Luís Alexandre Maffei Sartini Paulillo ◽  
Flávio Henrique Baggio Aguiar
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Physical Properties ◽  
Water Sorption ◽  
Testing Machine ◽  
Constant Mass ◽  
Fissure Sealant ◽  
Significant Difference ◽  
Materials Used ◽  
The Impact

ABSTRACTObjective: This study aimed to evaluate the impact of extended photoactivation time on ultimate tensile strength (UTS), water sorption (WS) and solubility (WSB) of resin-based materials used as fissure-sealantsMethods: A fissure-sealant (Fluroshield) and a flowable composite (Permaflo) polymerized for 20 and 60 seconds were tested. For UTS, 20 hourglass shaped samples were prepared representing two materials and two photoactivation time (n=5). After 24-h dry-storage, samples were tested in tension using a universal testing machine at a cross-head speed of 0.5 mm/min (UTS was calculated in MPa). For WS and WSB, 20 disks with 5 mm diameter and 1 mm height (n=5) were prepared and volumes were calculated (mm3). They were transferred to desiccators until a constant mass was obtained (m1) and were subsequently immersed in distilled water until no alteration in mass was detected (m2). Samples were reconditioned to constant mass in desiccators (m3). WS and WSB were determined using the equations m2-m3/V and m1-m3/V, respectively. Data were subjected to twoway ANOVA and Tukey’s HSD test (P<.05).Results: There was no significant difference between materials or photoactivation times for the UTS and WS. Permaflo presented lower but negative WSB compared to Fluroshield.Conclusions: Extended photoactivation time did not improve the physical properties tested. Fluroshield presented physical properties that were similar to or better than Permaflo. (Eur J Dent 2012;6:402-407)

Assessment of the Mechanical Properties of Three Commercially Available Thermoplastic Aligner Materials used for Orthodontic Treatment

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Alok Ranjan ◽  
Anil Kumar Biradar ◽  
Ankita Patel ◽  
Vanessa Varghese ◽  
Ankita Pawar ◽  
...  
Keyword(s):  
Stress Relaxation ◽  
Yield Strength ◽  
Tooth Movement ◽  
Testing Machine ◽  
Bending Test ◽  
P Value ◽  
Stress Release ◽  
Relaxation Properties ◽  
Intergroup Comparison ◽  
Materials Used

Objectives: This studied aimed to measure the yield strength and stress relaxation properties of three commercially available thermoplastic aligner materials. Methods: The three different thermoplastics aligner materials Duran (Scheu, Iserlohn, Germany), Erkodur (Pfalzgrafenweiler, Erkodent, Germany) and Track (Forestadent, Germany) were selected. A three-point bending test was carried out via the universal testing machine to measure their yield strength and stress relaxation properties. An independent t- test was performed for intergroup comparison. P-value < 0.05 was set as the level of significance. Results: All the selected three polymers liberate a notable amount of stress during 24 hours. The highest stress release was observed in Duran i.e. 18.96 N/cm2 as compared to Erkodur, which was 13.96 N/cm2 and Track, which was 13.18 N/cm2. The yield strength of Duran was the highest (75.85 Mpa) compared to Track and Erkodur with the yield strength of 52.75 Mpa and 55.86 Mpa, respectively. Conclusions: Tooth movement is influenced by the composition of aligner material and its thickness. Duran had the highest stress release and yield strength. Stress released by different aligners exceeds around half of the initial stress value, which directly affects the orthodontic force application and subsequent tooth movement.

The Preparation and Mechanical Properties of a Pure Titanium-Based Matrix Composite Reinforced with Graphene Nanoplatelets

2020 ◽  
Vol 12 (2) ◽  
pp. 296-303
Author(s):  
Zai-Yu Zhang ◽  
Yi-Long Liang ◽  
Hong-Chuan Cao ◽  
Yong Zhu
Keyword(s):  
Mechanical Properties ◽  
Matrix Composite ◽  
Testing Machine ◽  
Pure Titanium ◽  
Graphene Nanoplatelets ◽  
Matrix Composites ◽  
Dispersion Strengthening ◽  
Titanium Matrix ◽  
Vacuum Sintering ◽  
Materials Used

A lightweight titanium matrix composite material was fabricated by vacuum sintering using semi-powder metallurgy. The graphene nanoplatelets (GNPs) were used as a reinforcement for the titanium matrix composites. Fabricating the composite materials used three steps: dispersion, formation, and sintering. In particular, GNPs were dispersed by ionic liquid through a centrifugal testing machine instead of ball milling in the process. The better pressure for composite forming was 600 MPa. At the same time, the better sintering temperature and holding time were 1200 °C and 3 h. The influences of the GNP addition on the density, microstructure, and microhardness of the Ti/GNP composites were investigated. For the mechanical properties of the composites, we focused on the tensile strength with different GNP contents. The Ti 0.075 wt% and Ti 0.15 wt% GNP composites exhibited yield strengths of 850 and 948 MPa, which demonstrated 66% and 85% increase compared to those of extruded titanium materials with no GNP additive (512 MPa yield strength). The main strengthening mechanisms of Ti/GNP composites are grain refinement strengthening, thermal mismatch strengthening, and dispersion strengthening.

Chemical Composition and Mechanical Properties of Bio-Derived Compact Bone Scaffolds

2006 ◽  
Vol 309-311 ◽  
pp. 891-894 ◽  
Author(s):  
Ting Wu Qin ◽  
Zhi Ming Yang ◽  
Xiang Tao Mo ◽  
Jing Cong Luo ◽  
Li Deng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heavy Metal ◽  
Chemical Composition ◽  
Compact Bone ◽  
Biomechanical Properties ◽  
Collagen Protein ◽  
Significant Difference ◽  
Calcium Phosphorus ◽  
And Control ◽  
Physical And Chemical

To compare the chemical composition and mechanical properties of the bio-derived compact bone scaffold (BDCBS) with the normal compact bone in human. Human compact bone were harvested and divided into control and experimental group. For the latter, BDCBS was prepared with physical and chemical methods. The major components (calcium, phosphorus, collagen protein) and heavy metal contents of the two groups were determined with biochemical assay. Histological examinations were performed to investigate the structure. Cylindroids from the normal compact bone and the BDCBS (6 in each group) were tested under compression. There was no significant difference between the two groups for major components. In addition, there were a few amounts of heavy metal components in BDCBS and control. Histological examinations confirmed the acellular structure in the BDCBS. Results from mechanical testing showed the compressive strength, elastic modulus and ultimate strain (193MPa, 13.76GPa, and 2.3%) of the BDCBS were a bit lower than those (205MPa, 15.67GPa, and 2.5% respectively) of control, but the differences were not statistically significant. In conclusion, there are almost the same matrix structure and composition with similar biomechanical properties between the BDCBS and the control. These results may underscore the potential of the BDCBS in tissue engineering bone.

Short Fiber Reinforced Composite: The Effect of Fiber Length and Volume Fraction

2006 ◽  
Vol 7 (5) ◽  
pp. 10-17 ◽  
Author(s):  
Lippo V.J. Lassila ◽  
Pekka K. Vallittu ◽  
Sufyan K. Garoushi
Keyword(s):  
Mechanical Properties ◽  
Fiber Length ◽  
Volume Fraction ◽  
Testing Machine ◽  
Short Fiber ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite

Abstract Aim The aim of this study was to determine the effect of short fiber volume fraction and fiber length on some mechanical properties of short fiber-reinforced composite (FRC). Methods and Materials Test specimens (2 x 2 x 25 mm3) and (9.5 x 5.5 x 3 mm3) were made from short random FRC and prepared with different fiber volumes (0%-22%) and fiber lengths (1-6 mm). Control specimens did not contain fiber reinforcement. The test specimens (n=6) were either dry stored or thermocycled in water (x10.000, 5 – 55°C) before loading (three-point bending test) according to ISO 10477 or statically loaded with a steel ball (Ø 3.0 mm) with a speed of 1.0 mm/min until fracture. A universal testing machine was used to determine the flexural properties and the load-bearing capacity. Data were analyzed using analysis of variance (ANOVA) (p=0.05) and a linear regression model. Results The highest flexural strength and fracture load values were registered for specimens with 22 vol% of fibers (330 MPa and 2308 N) and with 5 mm fiber length (281 MPa and 2222 N) in dry conditions. Mechanical properties of all test specimens decreased after thermocycling. ANOVA analysis revealed all factors were affected significantly on the mechanical properties (p<0.001). Conclusions By increasing the volume fraction and length of short fibers up to 5 mm, which was the optimum length, the mechanical properties of short FRC were improved. Citation Garoushi SK, Lassila LVJ, Vallittu PK. Short Fiber Reinforced Composite: The Effect of Fiber Length and Volume Fraction. J Contemp Dent Pract 2006 November;(7)5:010-017.

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