scholarly journals Tip and Torque Accuracy According to the ISO 27020:2019 Norm in Currently Available Pre-Adjusted Orthodontic Brackets

2021 ◽  
Vol 11 (24) ◽  
pp. 11657
Author(s):  
Laura Bernes Martinez ◽  
Daniele Garcovich ◽  
Alfonso Alvarado Lorenzo ◽  
Angel Zhou Wu ◽  
Riccardo Aiuto ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Manufacturing Process ◽  
Metal Injection Molding ◽  
Central Incisor ◽  
Tolerance Limits ◽  
Mean Values ◽  
Slot Size ◽  
Torque Values ◽  
Single Blind ◽  
Correct Expression

Background: The precision of bracket manufacturing is fundamental to ensure the correct expression of the inbuilt information. The objective of this study was to determine the actual tip and torque values of a pool of stainless steel brackets, pre-adjusted according to the MBT prescription values, and to compare these actual values with those stated by the manufacturers in order to test their compliance with the tolerance limits reported in the ISO 27020:2019 Methods: A sample of 360 stainless steel brackets, from 12 different providers, were evaluated. All brackets had a nominal slot size of 0.022 in., belonged to the upper right central incisor, and were manufactured with the metal injection molding technique (MIM). For each provider, three different batches of the same bracket series were tested. A single-blind design was used for bracket coding. Results: Only five systems displayed torque mean values that matched the declared values (p > 0.05). Only one system did not respect the tolerance limits established in the ISO 27020:2019 norm. The tip values were different from those declared in seven of the assessed systems; however, none exceeded the tolerance limits. The inter-batch variability in most cases was not statistically significant. Conclusions: In most of the assessed systems, there can be a difference between the actual and the declared torque values, while tip information is usually accurately incorporated into the bracket slot. Lack of precision in the manufacturing process can reduce the efficacy of the appliance and force the clinician to compensate for dimensional inaccuracy through wire bending.

scholarly journals A Comparative Study of the In-Built Torque and Slot Size of MBT Prescription Bracket of Different Manufacturing Companies: A Stereo-Microscopic Study

2020 ◽  
Vol 54 (4) ◽  
pp. 297-303
Author(s):  
Ashish Mathew ◽  
HC Kiran Kumar ◽  
Sadashiva Shetty
Keyword(s):  
Comparative Study ◽  
Manufacturing Companies ◽  
Central Incisor ◽  
Mean Values ◽  
Significant Difference ◽  
Slot Size ◽  
Standard Value ◽  
The Mean ◽  
Torque Values ◽  
The Ideal

Torque is produced by a twist in an “archwire” that creates a couple when interacted with a “bracket slot.” Depending on the magnitude of the twist, the size of the wire, the built-in torque and the size of the slot, the archwire expresses torsional forces to the teeth. When brackets are manufactured, some variations may inadvertently occur in the dimensions of the bracket slot. Hence this study was done to determine the accuracy of different manufacturer’s dimensions of bracket slots and the built-in torque. Method: Seven upper right central incisor brackets of Mclaughlin Bennet and Trevisi (MBT) prescription with 0.022-inch slot from 5 different manufacturers were taken to assess the accuracy of bracket slot dimensions and built-in torque. A stereomicroscope was used to accurately determine slot dimensions and built-in torque. Results: The results showed that all the bracket slots measured in this study were oversized when compared to the standard value. Dentaurum showed significant difference from the ideal slot size and brackets from JJ Orthodontics and Desires showed highly significance difference from ideal slot size. The mean values for built in torque were less in all the brackets. The brackets from JJ Orthodontics and Desires showed highly significant difference from the ideal built in torque values. Interpretation and Conclusion: The above findings of the study suggest that one should be cautious when choosing a commercially available brand in day to day practice as some of the materials may not fulfill the desired standards.

scholarly journals Compliance with the ISO 27020:2019 norm of a sample of currently available preadjusted Orthodontic bracket systems. Are the actual dimensions as expected?

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Laura Bernés Martínez ◽  
Daniele Garcovich ◽  
Pilar España Pamplona ◽  
Milagros Adobes Adobes Martín ◽  
Alfonso Alvarado Lorenzo
Keyword(s):  
Stainless Steel ◽  
Dimensional Accuracy ◽  
Orthodontic Brackets ◽  
Metal Injection Molding ◽  
Tolerance Limits ◽  
Orthodontic Bracket ◽  
Significant Difference ◽  
Conventional Brackets ◽  
Slot Size ◽  
The Right

Abstract Background Determine the exact slot dimension of a sample of a MBT prescription stainless steel conventional brackets from different manufacturers to compare the actual values with the nominal ones declared by the manufacturers and to verify the compliance with tolerance limits given by the ISO 27020:2019. Different batches from each manufacturer were evaluated to determine whether or not they are different in size. In addition, the geometry of the slot walls was assessed. Methods 360 stainless steel preadjusted orthodontic brackets of 12 different manufacturers were assessed. All brackets had a nominal slot size of 0.022 by 0.028 inches, belonged to the right upper central incisor, and were fabricated with the metal injection molding technique (MIM). For each manufacturer, three different manufacturing batches were evaluated. Brackets were coded using a single-blind design. Results All bracket systems in the study group except one displayed a statistically significant difference with the nominal declared value, although only four of the systems did not comply with the tolerance limits established by the ISO 27020:2019. In most of the systems, the slot height was oversized when compared to the nominal one. A significant interbatch variability was found in most of the evaluated systems. Most of the brackets walls were divergent. Conclusions The dimensional accuracy of commercially available metal brackets is not guaranteed. The respect for the norm should be enforced as well as the quality controls along the manufacturing process since orthodontic brackets are a precision medical device.

scholarly journals New Manufacturing Process of Nickel-Free Austenitic Stainless Steel with Nitrogen Absorption Treatment

2003 ◽  
Vol 44 (3) ◽  
pp. 414-420 ◽  
Author(s):  
Daisuke Kuroda ◽  
Takao Hanawa ◽  
Takaaki Hibaru ◽  
Syuji Kuroda ◽  
Masaki Kobayashi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Manufacturing Process ◽  
Nitrogen Absorption

Effects of Sintering Variables on the Physical and Mechanical Properties of Metal Injection Molding Molded 17-4 PH Stainless Steel

2021 ◽  
Vol 1028 ◽  
pp. 403-408
Author(s):  
Apang Djafar Shieddieque ◽  
Shinta Virdhian ◽  
Moch Iqbal Zaelana Muttahar ◽  
Muhammad Rafi Muttaqin
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Injection Molding ◽  
Relative Density ◽  
Physical And Mechanical Properties ◽  
High Hardness ◽  
Argon Atmosphere ◽  
Metal Injection Molding ◽  
Manufacturing Method ◽  
Small Complex

Metal injection molding (MIM) is a near net shape manufacturing technique for producing small, complex, precision parts in mass production. MIM process is manufacturing method that combines traditional shape-making capability of plastic injection molding and the materials flexibility of powder metallurgy. The process consists of the following four steps: mixing of metal powder and binder, injection molding to shape the component, debinding to remove the binder in the component, sintering to consolidate the debound parts. In this research, the physical and mechanical properties of metal injection molded 17-4 PH stainless steel were investigated with the variation of sintering temperatures (1300 °C - 1360 °C) and atmosphere conditions (argon and vacuum conditions). The relative density, microstructure, distortion, and hardness are measured and analyzed in this study. The results show that highest relative density of 87%, relative homogeneous shrinkage and high hardness are achieved by sintering at 1360 °C for 1.5 hours and argon atmosphere. At the same sintering temperature and time, sintering in vacuum shows lower relative density (81%) than that in argon condition due to pores growth. The pore growths were not observed in the argon atmosphere. It can be concluded that sintering stages more rapidly under vacuum condition. The hardness measurements result also showed that high hardness is obtained by high density parts. The optimum average hardness obtained in this study is 239 HV. However, the hardness properties results are still lower than 280 HV according to MPIF Standard 35 for MIM parts.

Comparative assessment of odontometric parameters for gender determination: A hospital based cross-sectional study

2021 ◽  
Vol 8 (3) ◽  
pp. 147-152
Author(s):  
Mosmi Lomi ◽  
Jonathan Daniel M
Keyword(s):  
Sexual Dimorphism ◽  
Cross Sectional Study ◽  
Mean Value ◽  
The Body ◽  
Central Incisor ◽  
Maxillary Canine ◽  
Cross Sectional ◽  
Mean Values ◽  
Gender Determination ◽  
Significant Difference

Determining gender is one of the most important procedure in forensics. Teeth are made of the most enduring mineralized tissues in the body, as such, they have an extraordinary resistance to putrefaction and the effects of external agents (physical, thermal, mechanical, chemical or biological) which makes them invaluable material for anthropological, genetic, odontologic and forensic examinations.i)To assess the degree of sexual dimorphism in maxillary canine using maxillary canine index, maxillary first molar and central incisor using mesiodistal (MD) and buccolingual/buccopalatal (BL) dimensions of the crown. ii) To determine the accuracy of maxillary canine index, first molar and central incisor dimensions (mesiodistal and buccolingual/buccopalatal) in determining sex.This study consisted of total 30 participants (males=15, females=15) of age group ranging from 20 to 35 yrs. Measurement of dimensions of selected teeth were performed on maxillary cast using digital Vernier caliper, resolution 0.01mm. Data thus obtained were analyzed statistically.The mean values of all the measurements in males were greater than females. There was statistical significant difference in mean value of bucco-lingual width of molar, mesiodistal width of canine (on left side, right side and average) and the inter-canine distance between males and females. The buccolingual width of molar showed the highest % of sexual dimorphism (5.33%) and the mesiodistal width of molar showed the least % of dimorphism (0.7%). Bucco-lingual width of molar posed the highest prediction accuracy for gender determination. We conclude that buccolingual width of maxillary first molar can be used to predict the gender when only teeth of maxillary arch are available for forensic examination.

The Characterization and Flow Behavior of 316L Stainless Steel Feedstock for Micro Metal Injection Molding (μMIM)

2010 ◽  
Vol 44-47 ◽  
pp. 2872-2876
Author(s):  
Pei Li Haw ◽  
Norhamidi Muhamad ◽  
Hadi Murthadha
Keyword(s):  
Stainless Steel ◽  
Injection Molding ◽  
316L Stainless Steel ◽  
Flow Behavior ◽  
Palm Stearin ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Binder System ◽  
Molding Process ◽  
Rheological Characterization

The rheological behaviors of the Micro Metal Injection Molding feedstock are important for the stability of the feedstock during micro injection molding process and quality of the final micro-components. Homogeneous feedstocks are preferable for MIM process to ensure the dimensional consistency of molded components and prevent the defects of powder-binder separation or particle segregation. In this work, feedstocks with various formulations of 316L stainless steel and binder system were prepared by using Brabender Plastograph EC Plus mixer. The binder system comprises of palm stearin, polyethelene (PE) and stearic acid. In order to obtain the viscosity, activation energy, flow behavior and mold ability index, the rheological characterization of the feedstocks were investigated in numerous conditions by using Shimadzu 500-D capillary rheometer The study showed that all of the 316L stainless steel feedstocks are homogenous with pseudo-plastic behaviors.

Manufacturing Process and Property Evaluation of Functional Composite Yarn-Dyed Woven Fabrics Made from Bamboo Charcoal/Stainless Steel and TPU

2008 ◽  
Vol 55-57 ◽  
pp. 413-416 ◽  
Author(s):  
C.I. Huang ◽  
C.I. Su ◽  
Ching Wen Lou ◽  
Wen Hao Hsing ◽  
Jia Horng Lin
Keyword(s):  
Stainless Steel ◽  
Manufacturing Process ◽  
Far Infrared ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Weft Yarn ◽  
Bamboo Charcoal ◽  
Functional Composite ◽  
Composite Yarn ◽  
Composite Fabrics

Recently, development of technology increases human life quality and gradually raises the value of health protection in human’s concept. Bamboo has multi-functional including far infrared radiation, deodorization and anion generation. Therefore, bamboo charcoal has been widely used in textile industry. Moreover, development of technology also increased the electromagnetic hazard in human’s daily life. This study aims to develop a manufacturing process of functional composite yarn-dyed woven fabrics. In the manufacturing process, the materials included pure cotton yarn, stainless steel fiber(called metallic yarn) and viscose rayon yarn containing bamboo charcoal (called bamboo charcoal yarn) were used for making the bamboo charcoal/stainless steel composite woven fabric. The composite woven fabrics were woven by using same warp yarn and two kinds of weft yarn that contained bamboo charcoal and stainless steel. The composite fabrics had two different structures. Those fabrics were changed the order of bamboo charcoal yarn and metallic yarn. The ratios of weft yarn were 1 end of bamboo charcoal yarn to 1 end of metallic yarn and 3 ends of bamboo charcoal yarn to 1 end of metallic yarn. Furthermore, the fabrication of composite fabrics that included plain, 2/2 twill and dobby were changed. The composite woven fabrics were finished and laminated by TPU film to enhance the waterproof and vapor permeable functions. The laminated composite fabrics were evaluated by far-infrared coefficient, anion generation rate, water vapor permeability, water resistance, surface electric resistance and electromagnetic shelter property to obtained optimal manufacturing process.

Defining Flexibility and Sewability in Conductive Yarns

2002 ◽  
Vol 736 ◽  
Author(s):  
Margaret Orth
Keyword(s):  
Mathematical Model ◽  
Stainless Steel ◽  
Manufacturing Process ◽  
Permanent Deformation ◽  
Stress And Strain ◽  
Lateral Stress ◽  
Electronic Textiles ◽  
Qualitative Properties ◽  
Textile Manufacturing ◽  
Conductive Yarns

ABSTRACTIn order for electronic textiles to truly qualify as textiles, they must maintain one of the intrinsic qualities of textiles, flexibility, or the ability to resist permanent deformation under bending, lateral stress and strain. Flexibility will allow electric textiles to be intimate, soft, wearable, conformable and durable. Unfortunately, flexibility is poorly understood by many researchers who come from a traditional electronics background. This paper presents some common terminology of textiles, and different approaches to understanding flexibility in fibers and yarns. Because one of the most mechanically stressful textile manufacturing process is machine sewing and embroidery, this paper defines the necessary properties of machine sewable yarns and demonstrates a formal Curl Test for judging the sewability and flexibility of stainless steel yarns. This paper also examines flexibility in yarns and fibers, historically and based on a mathematical model and more qualitative properties.

Characterization and Rheological Studies on Ready-Made Feedstock of Stainless Steel 316L in Metal Injection Molding (MIM) Process

2013 ◽  
Vol 465-466 ◽  
pp. 709-714 ◽  
Author(s):  
N.H. Mohamad Nor ◽  
Muhammad Hussain Ismail ◽  
Nur Atikah Abu Kasim ◽  
N. Muhamad ◽  
M.A. Taib
Keyword(s):  
Stainless Steel ◽  
Current Trend ◽  
Metal Injection Molding ◽  
Total Weight Loss ◽  
Capillary Rheometer ◽  
Stainless Steel 316L ◽  
Flow Behaviour Index ◽  
Crucial Part ◽  
Advanced Applications ◽  
Behaviour Index

Current trend for manufacturers associated to MIM industry try to enhance the feedstock in term of its characteristics, since it is the most crucial part of the MIM process. This paper covered the characterization and rheological studies on a ready-made feedstock of stainless steel 316L which is vital to determine the availability and suit the needs of many advanced applications. There are three different experiments involved which are Scanning Electron Microscope (SEM), Differential Scanning Calorimeter (DSC), Thermogravimetric (TGA) and Capillary Rheometer. Observation through SEM gives an insight of the bonding microstructure matrices of the feedstock and also determines the homogeneity of the feedstock. DSC testing defines the melting temperature of the 3 binders used which are 62.07°C for surfactant, 178.72°C for filler and 236.61°C for backbone binder. From TGA result, it showed that the total weight loss of feedstock was 39%. Throughout the capillary rheometer testing, the feedstocks viscosity was decreasing as the shear rate increasing. The feedstock exhibits pseudoplastic behaviour since its flow behaviour index was less than 1. It is founded that at the temperature of 190°C, the feedstock exhibits the best characteristics for injection.

Recyclability of stainless steel (316 L) powder within the additive manufacturing process

Materialia ◽  
2019 ◽  
Vol 8 ◽  
pp. 100489 ◽  
Author(s):  
Nima E. Gorji ◽  
Rob O'Connor ◽  
Andre Mussatto ◽  
Matthew Snelgrove ◽  
P.G. Mani González ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Manufacturing Process
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