scholarly journals Accuracy of Single-Step versus 2-Step Double-Mix Impression Technique

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Eduardo Batista Franco ◽  
Leonardo Fernandes da Cunha ◽  
Francyle Simões Herrera ◽  
Ana Raquel Benetti
Keyword(s):  
Stainless Steel ◽  
Single Step ◽  
Tukey Test ◽  
Measuring Microscope ◽  
Impression Technique ◽  
Crown Preparation

Objective. To investigate the accuracy of dies obtained from single-step and 2-step double-mix impressions. Material and Methods. Impressions (n=10) of a stainless steel die simulating a complete crown preparation were performed using a polyether (Impregum Soft Heavy and Light body) and a vinyl polysiloxane (Perfectim Blue Velvet and Flexi-Velvet) in two consistencies, in one or two (without relief) steps. Accuracy of the stone dies was accessed at a measuring microscope, using a metallic crown with perfect fit to the reference crown preparation. Data were submitted to 2-way ANOVA and Tukey test (α=0.05). Results. The single-step technique resulted in slightly larger dies, while the 2-step technique without relief produced significantly smaller dies, when compared to the original stainless steel die. Stone dies obtained from 2-step polyether impressions were significantly smaller when compared to dies obtained from 2-step vinyl polysiloxane impressions (Impregum 2-step: −290.94 ± 71.64 μm; Perfectim 2-step: −201.86 ± 28.58 μm). No significant differences were observed in dies obtained from either polyether or vinyl polysiloxane with the single-step technique (Impregum single-step: 63.52 ± 16.60 μm; Perfectim single-step: 79.40 ± 14.11 μm). Conclusion. Higher discrepancies were detected for the 2-step impression technique without relief for the investigated materials.

Single Step Impression Technique - A Case Report

2015 ◽  
Vol 3 (2) ◽  
pp. 13
Author(s):  
Niyati Singh ◽  
Seema Mufti ◽  
Snigdha Singh ◽  
Ajay Singh
Keyword(s):  
Case Report ◽  
Single Step ◽  
Impression Technique

Effect of the Crown Preparation Margin and Die Type on the Marginal Accuracy of Fiber-reinforced Composite Crowns

2008 ◽  
Vol 9 (2) ◽  
pp. 9-16 ◽  
Author(s):  
Mohamed F. Ayad
Keyword(s):  
Epoxy Resin ◽  
Finish Line ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Measuring Microscope ◽  
Significant Difference ◽  
Die Material ◽  
Tooth Preparation ◽  
The Difference ◽  
Crown Preparation

Abstract Aim The objective of this laboratory investigation was to determine the effect of different preparation designs (light chamfer, deep chamfer, and shoulder) and die-making materials (stone and epoxy) on the resulting margin misfit for fiber-reinforced composite crowns using a measuring microscope. Methods and Materials Sixty standardized FibreKor crowns were made on stone and epoxy resin dies (n=30 each) duplicated from three metal master dies representing complete crown tooth preparation with a total convergence of 5°. For each die group, three of the tooth preparation designs were established in relation to the type of finish line (n=0 each) as follows: Group A (0.5-mm light chamfer finish line); Group B (1.0-mm deep chamfer finish line); and Group C (1.0-mm shoulder finish line). Marginal accuracy was evaluated by measuring the distances between each of four pairs of indentations on the crowns and on the dies with a Nikon measuring microscope. Results Analysis of seating measurements with parametric analysis of variance and Tukey's Studentized Range (HSD) disclosed a statistically significant difference for both tooth preparation design and die material (p< 0.001). However, the interaction effect was not significant (p=0.9073). The least marginal opening value was for FibreKor crowns made on epoxy resin dies with a light chamfer finish line (57 μm), but the difference was not statistically significantly different from crowns made on epoxy resin dies with a deep chamfer light chamfer finish line (61 μm). However, crowns made on epoxy resin dies with a shoulder finish line (81 μm) had significantly higher values (p< 0.05). FibreKor crowns made on stone dies with the shoulder finish line (95 μm) had statistically higher marginal opening values (p< 0.05). The least marginal opening value was for crowns made on stone dies with a light chamfer finish line (66 μm), but the difference was not statistically significantly different from crowns made on stone dies with a deep chamfer light chamfer finish line (70 μm). Conclusions Significant differences were found among the die material used for the shoulder margin design. However, there was no significant difference between light chamfer and deep chamfer margin designs for both die materials. Citation Ayad MF. Effect of the Crown Preparation Margin and Die Type on the Marginal Accuracy of Fiberreinforced Composite Crowns. J Contemp Dent Pract 2008 February;(9)2:009-016.

scholarly journals Effectiveness of low binding frictional materials: Evaluation of the binding frictional resistance of improved superelastic nickel-titanium alloy wires with different bracket combinations

2019 ◽  
Vol 9 ◽  
pp. 156-164 ◽  
Author(s):  
Yoshio Shima ◽  
Akihiro Koyama ◽  
Motohiro Uo ◽  
Takashi Ono
Keyword(s):  
Stainless Steel ◽  
Titanium Alloy ◽  
Orthodontic Treatment ◽  
Steel Wire ◽  
Frictional Resistance ◽  
Nickel Titanium ◽  
Test Results ◽  
Tukey Test ◽  
Frictional Materials ◽  
Multibracket Appliance

Introduction: This study aimed to evaluate the binding frictional resistance of improved superelastic nickel- titanium alloy wires (ISW) with different bracket combinations and to verify the effectiveness of low binding frictional materials by applying them in orthodontic treatment. Materials and Methods: Straight stainless steel wire (SSW; 0.016 × 0.022-inch) and straight ISW (0.016 × 0.022- inch) were set to each displaced bracket, and the tensile resistance load was measured. The maximum tensile resistance load was statistically compared using the Tukey test. For exemplification, we treated a typical extraction case of Angle Class I crowding malocclusion with lip protrusion using lower binding frictional materials, which were selected based on tensile test results. Results: The SSW and metal bracket combination had the largest maximum tensile resistance load, and the ISW and metal slot-equipped plastic bracket combination had the smallest load (P < 0.01). In a patient treated using lower binding frictional materials, the active treatment period was 9 months. Satisfactory patient results were obtained without using reinforced anchorage. Conclusions: Binding frictional resistance varies, depending on the archwire and bracket combination. In a multibracket appliance, selecting materials with as low a binding frictional resistance as possible may make a more effective treatment.

CARPENTER PROJECT 70+ CUSTOM 630

Alloy Digest ◽  
2003 ◽  
Vol 52 (6) ◽  
Keyword(s):  
Stainless Steel ◽  
Low Temperature ◽  
Physical Properties ◽  
Heat Treating ◽  
Temperature Treatment ◽  
Single Step ◽  
Steel Type ◽  
Low Temperature Treatment ◽  
Conventional Stainless Steel

Abstract Carpenter Project 70+ Custom 630 is a modified version of conventional stainless steel Type 630 (17Cr-4Ni) with improved machinability. The alloy has good fabrication characteristics and can be age hardened by a single-step, low-temperature treatment. See also Carpenter Custom 630, Alloy Digest SS-258, revised December 2000, and Carpenter Project 70 Stainless Custom 630, Alloy Digest SS-732, November 1998. This datasheet provides information on composition and physical properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: SS-886. Producer or source: Carpenter Specialty Alloys.

EMPIRE ISO-450

Alloy Digest ◽  
1972 ◽  
Vol 21 (5) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Aging Treatment ◽  
High Strength ◽  
Heat Treating ◽  
Single Step ◽  
Excellent Corrosion Resistance ◽  
Steel Castings ◽  
Cast Stainless Steel

Abstract EMPIRE ISO-450 is a cast stainless steel with excellent corrosion resistance. A simple, single-step aging treatment develops high strength with good ductility and toughness. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: SS-273. Producer or source: Empire Steel Castings Inc..

scholarly journals Dimensional Accuracy of Stone Casts Obtained with Multiple Pours into the Same Mold

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Valdimar da Silva Valente ◽  
Artêmio Luiz Zanetti ◽  
Pedro Paulo Feltrin ◽  
Ricardo Tatsuo Inoue ◽  
Carmem Dolores Vilarinho Soares de Moura ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Wait Time ◽  
Type Iv ◽  
Impression Technique ◽  
Fixed Prosthesis ◽  
Measuring Machine ◽  
Master Model ◽  
Made In

Aim. The aim of the present study was to compare the dimensional accuracy of stone casts obtained with vinyl polysiloxane molds through the double-impression technique with three pours into the same mold. Methods. A stainless steel master model was constructed simulating a three-unit fixed prosthesis. Twelve impressions were taken of this master model with addition silicone, using the double-impression technique. Three pours of type IV gypsum were then made into each mold, thus producing 36 casts. The pours were made 1 hour, 6 hours and 24 hours after the impression procedure. Next, intra- and interabutment measurements were made in a coordinate measuring machine. Results. Comparative analysis of the dimensional accuracy of stone casts resulting from multiple pours was not statistically significant in pours first and second (P>0.05). These values, however, were statistically significant at third pour in the height in abutment 1 and upper distance interabutment. Conclusion. The wait time (1 hour, and 6 hours) observed before pouring the stone into the same molds did not cause significant dimensional accuracy of the casts.

Evaluation of Methods of Enrichment and Compositing of Environmental Samples for Detection of Listeria monocytogenes

2020 ◽  
Author(s):  
Joelle K Salazar ◽  
Megan Fay ◽  
Christine Eckert ◽  
Diana Stewart ◽  
Vanessa Cranford ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Environmental Samples ◽  
Food Production ◽  
Single Step ◽  
Romaine Lettuce ◽  
Control Plan ◽  
Enrichment Broth ◽  
University Of Vermont ◽  
Enrichment Methods ◽  
Evaluation Of Methods

Various methods exist for the enrichment and detection of Listeria spp. and L. monocytogenes from environmental samples. Procedures for the compositing of environmental samples are not as well-defined. In this study, different enrichment procedures involving Buffered Listeria Enrichment Broth (BLEB), University of Vermont Medium (UVM), and Fraser Broth (FB) were evaluated to determine the limits of detection (LOD) for L. monocytogenes from culture and from swabs of stainless steel and to assess the efficacy of composite sampling by wet (pooling of primary enrichments) and dry (pooling of swabs) procedures. For detection of cells in pure culture, the computed LOD95% values using a single-step BLEB or two-step UVM-FB enrichment were 0.33 and 0.49 CFU per 225 mL enrichment, respectively. No significant differences in detection were observed for procedures using either two-step BLEB-FB or UVM-FB enrichments for swabs of stainless steel when L. monocytogenes was inoculated at 2-6 log CFU; LOD95% values were 3.82 and 3.62 log CFU per 4 in2 area, respectively. Wet compositing of L. monocytogenes from culture with and without Romaine lettuce wash (RLW) resident microbiota was conducted using BLEB-FB and UVM-FB enrichment methods; both allowed detection of the pathogen at ratios of 1:1, 1:2, 1:4 and 1:7 (1 positive : x negative samples) with no loss in sensitivity. From swabs of stainless steel, L. monocytogenes was detected similarly for both wet and dry composites of up to eight samples (1:7) with RLW. However, the BLEB-FB method allowed for significantly faster detection (after 24 h of FB incubation) in composites of 1:4 and 1:7 compared to the UVM-FB method under the conditions tested. The results of this study provide data to evaluate the efficacies of the different enrichment procedures and aid in assessing the use of wet and dry compositing of environmental samples for use in food production and processing facilities as part of a Listeria control plan.

Infulence of Chemical Composition and Metallographic Structure to Dimagnetic Stainless Steel

2015 ◽  
Vol 667 ◽  
pp. 298-302
Author(s):  
Qi Wen Zeng ◽  
Zhi Ming Zhang
Keyword(s):  
Stainless Steel ◽  
Chemical Composition ◽  
Single Step ◽  
Step Motor ◽  
Rotating Speed ◽  
Metallographic Structure ◽  
Manufacture Process ◽  
Special Environment

A kind of rotating step motor is used in special environment, which has the character of single step angle great,single step rotating speed rangeing widely and output turque rangeing widely. To adapt the using environment and its working characteristics, the motor’s main parts of shell and front-backcovers are all made up of the stainless steel 1Cr18Ni9Ti, which has a good performance in diamagnetic and comperhensive mechanics. During the manufacture process, the 1Cr18Ni9Ti was found can be absorded by magnet. This paper researchs the influence of elements components and metallographic structure to the 1Cr18Ni9Ti by analyzing the element components and metallographic structure of several batches of materials.

scholarly journals Maxillary incisor retraction: evaluation of different mechanisms

2013 ◽  
Vol 18 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Antônio Carlos de Oliveira Ruellas ◽  
Matheus Melo Pithon ◽  
Rogério Lacerda dos Santos
Keyword(s):  
Stainless Steel ◽  
Heat Source ◽  
Analysis Of Variance ◽  
Steel Wire ◽  
The Other ◽  
Maxillary Incisor ◽  
Tukey Test ◽  
Group A ◽  
Incisor Retraction ◽  
Incisor Inclination

OBJECTIVE: To mechanically evaluate different systems used for incisors retraction. METHODS: Three different methods for incisors retraction using 0.019 x 0.025-in stainless steel wire were evaluated. The samples were divided into three groups: Group A (retraction arch with 7-mm high vertical hooks); Group G3 (elastic chain attached to the miniimplant and to the 3-mm stainless steel hook soldered to the retraction arch); Group G6 (elastic chain attached to the mini-implant and to the 6-mm stainless steel hook soldered to the retraction arch). A dental mannequin was used for evaluation in order to simulate the desired movements when the device was exposed to a heat source. The analysis of variance (ANOVA) and the Tukey test were used (p < 0.05). RESULTS: The results demonstrated that Groups G3 and G6 exhibited less extrusion and less incisor inclination during the retraction phase (p < 0.05). With regard to incisor extrusion, statistically significant differences were observed between Groups A and G3, and between Groups A and G6 (p < 0.05). Regarding incisor inclination, statistically significant differences were observed between the three systems evaluated (p < 0.05). CONCLUSIONS: Arches with 6-mm vertical hooks allow the force to be applied on the center of resistance of the incisors, thus improving mechanical control when compared with the other two systems.

Fabrication of Semi-Solid Slurry for Steels and Their Rheo-Rolling Process

2008 ◽  
Vol 141-143 ◽  
pp. 457-461 ◽  
Author(s):  
Ren Bo Song ◽  
Yong Lin Kang ◽  
Aimin Zhao
Keyword(s):  
Stainless Steel ◽  
Melting Point ◽  
Metal Forming ◽  
Steel Ingot ◽  
Research Work ◽  
Basic Research ◽  
Rolling Process ◽  
Single Step ◽  
Spring Steel ◽  
Semi Solid

Semi-solid metal forming (SSM) has been recognized as a new forming technology, which is different from the present metal forming methods. Basic research on SSM has been put into operation and a number of SSM techniques have been widely applied in industry. In the application of SSM technique, at present, it is mainly used to produce the low melting point alloys such as Al-base, Zn-base and Mg-base alloys, but the high melting point alloys, for example steels as the most widely useful metal are not extensively studied and applied. In the present work, the electromagnetic stirring method was used to prepare semi-solid slurry of spring steel–60Si2Mn and stainless steel–1Cr18Ni9Ti. At the same time, spring steel–60Si2Mn and stainless steel–1Cr18Ni9Ti were directly rolled into thick strips in the semi-solid state (Rheo-rolling). It is aimed at studying the microstructure and properties of the strips to establish the feasibility of rheo-rolling for the production of the steel strips. According to the present research work, it has been shown that rheo-rolling process combines the casting and hot rolling into a single step for near net-shape production, compared with the conventional hot-rolled metallurgical process. Besides being such a cost-effective process, rheo-rolling process possesses irregular crystal grains such as rosette-type primary crystals in the microstructures because of sufficient agitation during solidification. The overall homogenization of the macrostructures in the whole part of steel ingot can be achieved.

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