scholarly journals Scanning Accuracy of Bracket Features and Slot Base Angle in Different Bracket Materials by Four Intraoral Scanners

2020 ◽  
Author(s):  
Seon-Hee Shin ◽  
Hyung-Seog Yu ◽  
Jung-Yul Cha ◽  
Jae-Sung Kwon ◽  
Chung-Ju Hwang
Keyword(s):  
Stainless Steel ◽  
Orthodontic Treatment ◽  
Sem Images ◽  
Polycrystalline Alumina ◽  
Base Angle ◽  
Accurate Expression ◽  
Dental Model ◽  
Alumina Composite ◽  
The Difference

Accurate expression of bracket prescription is important for successful orthodontic treatment. The aim of this study was to evaluate the accuracy of digital scan images of brackets produced by four different intraoral scanners (IOSs) in terms of the height, position, and angle of the bracket slot when scanning the surface of dental model attached with bracket materials made from different composition of materials. Brackets made from stainless steel, polycrystalline alumina, composite and composite/stainless steel slot were considered, which have been scanned from 4 different IOSs (Primescan, Trios, CS3600 and i500). SEM images were used as references. Each bracket axis was set in the reference scan image, and the axis was set identically by superimposing with the IOS image, and then only the brackets were divided and analyzed. The difference between the manufacturer's nominal torque and bracket slot base angle was 0.39 in SEM, 1.96 in Primescan, 2.04 in Trios, and 5.21 in CS3600 (P <0.001). The parallelism, which is the difference between the upper and lower angles of the slot wall, was 0.55 in SEM, 7.55 in Primescan, 6.74 in Trios3, 6.59 in CS3600, and 24.95 in i500 (p <0.001). This study evaluated the accuracy of the bracket only and it must be admitted that there is some error in recognizing slots through scanning in general

scholarly journals Scanning Accuracy of Bracket Features and Slot Base Angle in Different Bracket Materials by Four Intraoral Scanners: An In Vitro Study

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 365
Author(s):  
Seon-Hee Shin ◽  
Hyung-Seog Yu ◽  
Jung-Yul Cha ◽  
Jae-Sung Kwon ◽  
Chung-Ju Hwang
Keyword(s):  
Stainless Steel ◽  
In Vitro Study ◽  
Sem Images ◽  
Polycrystalline Alumina ◽  
Base Angle ◽  
Accurate Expression ◽  
Dental Model ◽  
Alumina Composite ◽  
The Difference

The accurate expression of bracket prescription is important for successful orthodontic treatment. The aim of this study was to evaluate the accuracy of digital scan images of brackets produced by four intraoral scanners (IOSs) when scanning the surface of the dental model attached with different bracket materials. Brackets made from stainless steel, polycrystalline alumina, composite, and composite/stainless steel slot were considered, which have been scanned from four different IOSs (Primescan, Trios, CS3600, and i500). SEM images were used as references. Each bracket axis was set in the reference scan image, and the axis was set identically by superimposing with the IOS image, and then only the brackets were divided and analyzed. One-way analysis of variance (ANOVA) was used to compare the differences. The difference between the manufacturer’s nominal torque and bracket slot base angle was 0.39 in SEM, 1.96 in Primescan, 2.04 in Trios, and 5.21 in CS3600 (p < 0.001). The parallelism, which is the difference between the upper and lower angles of the slot wall, was 0.48 in SEM, 7.00 in Primescan, 5.52 in Trios, 6.34 in CS3600, and 23.74 in i500 (p < 0.001). This study evaluated the accuracy of the bracket only, and it must be admitted that there is some error in recognizing slots through scanning in general.

scholarly journals The effect of two different bracket types on the salivary levels of S mutans and S sobrinus in the early phase of orthodontic treatment

2012 ◽  
Vol 83 (1) ◽  
pp. 140-145 ◽  
Author(s):  
Antonija Jurela ◽  
Dario Repic ◽  
Slavica Pejda ◽  
Hrvoje Juric ◽  
Renata Vidakovic ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Statistical Analysis ◽  
Orthodontic Treatment ◽  
Orthodontic Appliance ◽  
Chi Square ◽  
Whole Saliva ◽  
Chi Square Test ◽  
The Difference ◽  
Plastic Brackets ◽  
Fixed Orthodontic Appliance

AbstractObjective:To determine the difference in the levels of Streptococcus mutans and S sobrinus in stimulated saliva in orthodontic patients with different bracket types (stainless steel and esthetic brackets) using polymerase chain reaction and cultivation method.Materials and Methods:Thirty-two patients, aged 13 to 30 years, were selected following these criteria: 1) orthodontic treatment indication, 2) systemic health, and 3) no tobacco and antibiotic consummation for three months prior to the commencement of the study. Patients were divided into two groups according to the bracket type; 16 patients formed the conventional bracket group (stainless steel brackets), and 16 patients formed the esthetic bracket group (plastic brackets). The levels of S mutans and S sobrinus in stimulated whole saliva samples were collected prior to fixed orthodontic appliance placement (T1) and 12 weeks after placement (T2), as were the Decayed, Missing, and Filled Surface Index (DMFS) and Oral Hygiene Index-Simplified (OHI-S). Mann-Whitney, Wilcoxon, and chi-square tests were used for statistical analysis.Results:Statistical analysis (chi-square test) showed no difference in S mutans and S sobrinus counts among patients with different brackets at either T1 or T2. There was no difference in total bacteria counts after fixed orthodontic appliance placement.Conclusion:The number of colony-forming units of S mutans and S sobrinus in stimulated saliva samples does not seem to be significantly different between patients with stainless steel brackets and patients with plastic brackets.

Characterization of oxide particles in ODS austenitic stainless steel after heavy ion irradiation up to high doses

2011 ◽  
Vol 1298 ◽  
Author(s):  
Hiroshi Oka ◽  
Yosuke Yamazaki ◽  
Hiroshi Kinoshita ◽  
Naoyuki Hashimoto ◽  
Somei Ohnuki ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ion Irradiation ◽  
Hot Extrusion ◽  
Oxide Dispersion Strengthened ◽  
Complex Oxide ◽  
Heavy Ion ◽  
Oxide Particles ◽  
The Difference ◽  
High Doses

ABSTRACTOxide dispersion strengthened austenitic stainless steel (ODS316), which is based on advanced SUS316 steel, has been developed by mechanically alloying and hot extrusion. Hafnium and titanium were added to make a fine distribution of oxide particles. The stability of oxide particles dispersed in ODS316 under irradiation was evaluated after 250 keV Fe+ irradiation up to high doses at 500 °C. TEM observation and EDS analysis indicated that fine complex oxide particles with Y, Hf and Ti were mainly dispersed in the matrix. There are no significant changes in the distribution and the size of oxide particles after irradiation. It was also revealed that the constitution ratio of Ti in complex oxide appeared to be decreased after irradiation. This diffuse-out of Ti during irradiation could be explained by the difference in oxide formation energy among alloying elements.

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 Robust low friction performance of graphene sheets embedded carbon films coated orthodontic stainless steel archwires

Friction ◽  
2021 ◽  
Author(s):  
Zonglin Pan ◽  
Qinzhao Zhou ◽  
Pengfei Wang ◽  
Dongfeng Diao
Keyword(s):  
Stainless Steel ◽  
Friction Coefficient ◽  
Orthodontic Treatment ◽  
Artificial Saliva ◽  
Carbon Film ◽  
Carbon Films ◽  
Graphene Sheets ◽  
Substrate Bias ◽  
Low Friction ◽  
Substrate Bias Voltage

AbstractReducing the friction force between the commercial archwire and bracket during the orthodontic treatment in general dental practice has attracted worldwide interest. An investigation on the friction and wear behaviors of the uncoated and carbon film coated stainless steel archwires running against stainless steel brackets was systematically conducted. The carbon films were prepared at substrate bias voltages from +5 to +50 V using an electron cyclotron resonance plasma sputtering system. With increasing substrate bias voltage, local microstructures of the carbon films evolved from amorphous carbon to graphene nanocrystallites. Both static and stable friction coefficients of the archwire-bracket contacts sliding in dry and wet (artificial saliva) conditions decreased with the deposition of carbon films on the archwires. Low friction coefficient of 0.12 was achieved in artificial saliva environment for the graphene sheets embedded carbon (GSEC) film coated archwire. Deterioration of the friction behavior of the GSEC film coated archwire occurred after immersion of the archwire in artificial saliva solution for different periods before friction test. However, moderate friction coefficient of less than 0.30 sustained after 30 days immersion periods. The low friction mechanism is clarified to be the formation of salivary adsorbed layer and graphene sheets containing tribofilm on the contact interfaces. The robust low friction and low wear performances of the GSEC film coated archwires make them good candidates for clinical orthodontic treatment applications.

scholarly journals Comparison of Mechanical Stability of Elastic Titanium, Nickel-Titanium, and Stainless Steel Nails Used in the Fixation of Diaphyseal Long Bone Fractures

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2159 ◽  
Author(s):  
Pei-Yuan Lee ◽  
Yen-Nien Chen ◽  
Jin-Jia Hu ◽  
Chih-Han Chang
Keyword(s):  
Stainless Steel ◽  
Mechanical Stability ◽  
Fe Simulation ◽  
Bone Fractures ◽  
Nickel Titanium ◽  
Long Bone ◽  
Bone Modeling ◽  
Long Bone Fractures ◽  
Elastic Nails ◽  
The Difference

Elastic nails made of the nickel-titanium shape memory alloy (Nitinol) have been reported to control bone modeling in animal studies. However, the mechanical stability of the Nitinol nail in the fixation of long bone fractures remains unclear. This study compared mechanical stability among nails made of three materials, namely Nitinol, titanium, and stainless steel, in the fixation of long bone fractures. These three materials had identical shapes (arc length: π/2 and radius: 260 mm). A cylindrical sawbone with a 10-mm gap and fixed with two C-shaped elastic nails was used to examine the stability of the nails. A finite element (FE) model was developed based on the sawbone model. The end cap for elastic nails was not used in the sawbone test but was considered based on a constraint equation in FE simulation. The results of stability tests appeared to depend on the presence or absence of the end cap. In the sawbone test, the titanium nail yielded a higher ultimate force against the applied load than did the stainless steel and Nitinol nails before the gap completely closed; the difference in linear stiffness between the nails was nonsignificant. In FE simulation, the titanium nail produced smaller gap shortening than did stainless steel and Nitinol nails without the end cap; the difference in gap shortening between the nails was minor with the end cap. The titanium elastic nail should be a better choice in managing diaphyseal long bone fractures when the end cap is not used. For Nitinol and stainless steel nails, the end cap should be used to stop the nail from dropping out and to stabilize the fractured bone.

scholarly journals Improving the Corrosion Resistance of AISI 316L Steel for Semiconductor Piping by Controlled Delta-Ferrite Content

2022 ◽  
Vol 60 (1) ◽  
pp. 46-52
Author(s):  
Young Woo Seo ◽  
Chan Yang Kim ◽  
Bo Kyung Seo ◽  
Won Sub Chung
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
316L Stainless Steel ◽  
Sem Analysis ◽  
Ferrite Content ◽  
Aisi 316L ◽  
Delta Ferrite ◽  
Aisi 316L Stainless Steel ◽  
316L Steel ◽  
The Difference

This study evaluated changes in delta-ferrite content depending on the preheating of AISI 316L stainless steel. We also determined the reasons for the variation in delta-ferrite content, which affects corrosion resistance. Changes in delta-ferrite content after preheating was confirmed using a Feritscope, and the microstructure was analyzed using optical microscopy (OM). We found that the delta-ferrite microstructure size decreased when preheating time was increased at 1295 oC, and that the delta-ferrite content could be controlled through preheating. Potentiodynamic polarization test were carried out in NaCl (0.5 M) + H2SO4 (0.5 M) solution, and it was found that higher delta-ferrite content resulted in less corrosion potential and passive potential. To determine the cause, an analysis was conducted using energy-dispersive spectroscopy (EDS), which confirmed that higher delta-ferrite content led to weaker corrosion resistance, due to Cr degradation at the delta-ferrite and austenite boundaries. The degradation of Cr on the boundaries between austenite and delta-ferrite can be explained by the difference in the diffusion coefficient of Cr in the ferrite and austenite. A scanning electron microscopy (SEM) analysis of material used for actual semiconductor piping confirmed that corrosion begins at the delta-ferrite and austenite boundaries. These results confirm the need to control delta-ferrite content in AISI 316L stainless steel used for semiconductor piping.

scholarly journals Effect of fixed orthodontic appliances on nonmicrobial salivary parameters

2018 ◽  
Vol 88 (6) ◽  
pp. 806-811 ◽  
Author(s):  
Ioannis P. Zogakis ◽  
Erez Koren ◽  
Shlomit Gorelik ◽  
Isaac Ginsburg ◽  
Miriam Shalish
Keyword(s):  
Orthodontic Treatment ◽  
Statistical Significance ◽  
Orthodontic Appliances ◽  
Inclusion Criteria ◽  
Reactive Protein ◽  
Fixed Orthodontic Appliances ◽  
Salivary Ph ◽  
Orthodontic Patients ◽  
The Difference ◽  
Ph Decrease

ABSTRACT Objectives: To examine possible changes in the levels of salivary antioxidants, C-reactive protein (CRP), cortisol, pH, proteins, and blood in patients treated with fixed orthodontic appliances. Materials and Methods: Salivary samples from 21 orthodontic patients who met specific inclusion criteria were collected before the beginning of orthodontic treatment (T0; baseline), 1 hour after bonding (T1), and 4–6 weeks after bonding (T2). Oxidant-scavenging ability (OSA) was quantified using a luminol-dependent chemiluminescence assay. Cortisol and CRP levels were measured using immunoassay kits. pH levels and presence of proteins and blood in the samples were quantified using strip-based tests. Results: A significant decrease in salivary pH was observed after bonding (P = .013). An increase in oxidant-scavenging abilities during orthodontic treatment was detected, but the change was not statistically significant. Cortisol and CRP levels slightly increased after bonding, but the difference was small without statistical significance. Changes in the presence of proteins and blood were also insignificant. Conclusions: Exposure to fixed orthodontic appliances did not show a significant effect on salivary parameters related to inflammation or stress, with the exception of a significant but transient pH decrease after bonding.

scholarly journals Salivary pH changes under the effect of stainless steel versus elastomeric ligatures in fixed orthodontic patients: a single-center, randomized controlled clinical trial

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hend Abulkarem Abdullah Al-Haifi ◽  
Ramy Abdulrahman Ali Ishaq ◽  
Maged Sultan Abdullah Al-Hammadi
Keyword(s):  
Clinical Trial ◽  
Stainless Steel ◽  
Orthodontic Treatment ◽  
Prolonged Treatment ◽  
Controlled Clinical Trial ◽  
P Value ◽  
Enamel Demineralization ◽  
Salivary Ph ◽  
Ph Level ◽  
Level Of Significance

Abstract Background Fluctuations in pH of saliva during a prolonged treatment course influences the enamel demineralization progress, which is one of the complications of fixed orthodontic treatment. This randomized clinical trial aimed to evaluate and compare the short-term effects of stainless steel (SS) versus elastomeric (EM) ligatures on salivary pH in patients scheduled for fixed orthodontic treatment. Methods Seventy participants were enrolled in the study (54 female, 16 male) aged 19–36 years who met specific inclusion criteria. They were randomly selected and allocated into two equal groups through computer-generated randomization. All patients received fixed orthodontic treatment using conventional orthodontic brackets. Two commonly used archwire ligature methods were used: SS and EMs. An unstimulated (resting) salivary sample was collected before tying of the ligatures at T0 (baseline), 2 weeks, 6 (weeks), and 12 (weeks). Salivary pH was measured using a digital pH meter. The level of significance was set at p value < 0.05. Results The salivary pH level was stable between T0 and T1 (6.72 ± 0.14), then significantly and progressively increased from T1 to T2 (6.78 ± 0.13) and from T2 to T3 (6.81 ± 0.14) with (p < 0.05) in the SS group. In the EM group, the salivary pH level was significantly decreased in all follow-up periods; T0 (6.77 ± 0.16), T1 (6.72 ± 0.14), T2 (6.67 ± 0.13) and T3 (6.64 ± 0.13). Conclusion The EM ligatures showed a significant decrease in salivary pH to an unfavorable level, which increased the risk of enamel demineralization. Therefore, EMs as ligature material is preferably should not be recommended in patients with high caries index or inadequate oral hygiene. Trial registration ANZCTR.org. (ACTRN12618001647224) http://www.anzctr.org.au/ACTRN12618001647224.aspx. Registration Date: 5/10/2018, “Retrospectively registered”.

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