Marginal fit of nickel-chromium copings before and after internal adjustments with duplicated stone dies and disclosing agent

2000 ◽  
Vol 83 (6) ◽  
pp. 634-643 ◽  
Author(s):  
Ossamu Ushiwata ◽  
João Vieira de Moraes ◽  
Marco Antonio Bottino ◽  
Eduardo Galera da Silva
Keyword(s):  
Marginal Fit ◽  
Nickel Chromium ◽  
Before And After

scholarly journals Evaluation of Marginal Misfit of Metal Frameworks Welded by Gas-Torch, Laser, and Tungsten Inert Gas Methods

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Wilson Matsumoto ◽  
Paula Pastana Beraldo ◽  
Rossana Pereira de Almeida ◽  
Ana Paula Macedo ◽  
Beatriz Roque Kubata ◽  
...  
Keyword(s):  
Inert Gas ◽  
Marginal Fit ◽  
Nickel Chromium ◽  
Before And After ◽  
Master Model ◽  
The One ◽  
Flexural Resistance ◽  
One Way Anova ◽  
Silicone Matrix ◽  
And Tungsten

Purpose. The objective of this study was to evaluate the marginal fit and the flexural resistance of nickel-chromium frameworks welded by different techniques, gas-torch, laser, and tungsten inert gas (TIG), compared with that of frameworks made via one-piece casting. Methods. To evaluate the marginal fit, a master model was fabricated simulating four implants. Transfers and replicas were used to transfer the positions of the implants to the model, using a silicone matrix. The bars were waxed up and casted. Three assessments of misfit were performed for each implant using a stereomicroscope before and after welding in two predetermined regions, totaling six readings for each implant. To evaluate the flexural resistance, one group was made casting the specimens in one piece. Other 3 groups using gas-torch, laser, and TIG welding techniques were made after sectioned transversally. The data showed normal distribution and two-way ANOVA for marginal fit and one-way ANOVA for flexural resistance, and Tukey’s posttest (α=0.05) was performed. Results. For the marginal fit, the three welding methods presented similar results and were different from one-piece casting. For the flexural resistance, significant differences were observed among the studied groups (p<0.001), and the one-piece group presented higher resistance compared to the three welding techniques. Conclusions. Within the limits of this study, the three welding techniques yielded similar misfit results, and the laser and TIG techniques presented similar flexural resistance but lower than gas-torch and one-piece casting.

Marginal fit of nickel-chromium copings before and after internal adjustments with duplicated stone dies and disclosing agent

2000 ◽  
Vol 83 (6) ◽  
pp. 0634-0643 ◽  
Author(s):  
Ossamu Ushiwata ◽  
Jo[atilde]o Vieira de Moraes ◽  
Marco Antonio Bottino ◽  
Eduardo Galera da Silva
Keyword(s):  
Marginal Fit ◽  
Nickel Chromium ◽  
Before And After

scholarly journals Marginal Adaptation of Implant Prostheses Fabricated by Different Materials in Excessive Crown Height Space Before and After Veneering

2021 ◽  
Author(s):  
Safoura Ghodsi ◽  
Marzieh Alikhasi ◽  
Majid Sahebi ◽  
Vahideh Nazari
Keyword(s):  
Repeated Measures ◽  
Marginal Adaptation ◽  
Crown Height ◽  
Second Molar ◽  
Basic Model ◽  
Nickel Chromium ◽  
Significant Difference ◽  
Before And After ◽  
Marginal Discrepancy ◽  
To Receive

Objectives: This study aimed to investigate the marginal adaptation of implant-supported three-unit fixed restorations fabricated in excessive crown height by various frameworks namely zirconia, nickel-chromium (Ni-Cr) alloy, and Polyetheretherketone (PEEK) before and after veneering. Materials and Methods: A basic model with two implant fixtures was made to receive posterior three-unit fixed partial dentures (second premolar to second molar) in 15 mm crown height. A total of 30 frameworks were fabricated using Ni-Cr, zirconia, and PEEK (n=10). All specimens were veneered and vertical marginal discrepancy was evaluated before and after veneering using a stereomicroscope (×75). The effect of framework material and veneering on marginal discrepancy was evaluated by repeated-measures and one-way ANOVA, and paired t test (α=0.05). Results: There was a significant difference between the groups (P<0.001) before and after veneering. The vertical marginal discrepancy of zirconia frameworks was significantly lower than that of other groups both before and after veneering (P<0.001). Statistical analysis revealed that the veneering process had a significant effect on marginal adaptation (P<0.001). Conclusion: In implant prostheses with excessive crown height, zirconia had the greatest marginal adaptaion significantly, followed by Ni-Cr. Veneering caused a significant increase in marginal discrepancy of all the materials.

Comparison of Marginal Fit of Cobalt-Chromium and Zirconia Cores Fabricated by Different Techniques Before and After Cementation

2015 ◽  
Vol 21 (2) ◽  
pp. 77-82
Author(s):  
Gamze ALNIAÇIK ◽  
Meryem Gülce SUBAŞI ◽  
Özgür İNAN ◽  
Mehmet MUHTAROĞULLARI
Keyword(s):  
Cobalt Chromium ◽  
Marginal Fit ◽  
Before And After

Comparative Analysis on the Precision Fit of Dental Prosthesis between the Variously Fabricated Copings of Nickel-Chromium Alloy, Titanium and Zirconia Ceramic

2007 ◽  
Vol 330-332 ◽  
pp. 1373-1376
Author(s):  
S.W. Lee ◽  
J.W. Kim ◽  
S.H. Hwang ◽  
Dong Hoo Han ◽  
H.S. Moon
Keyword(s):  
Comparative Analysis ◽  
Zirconia Ceramic ◽  
Chromium Alloy ◽  
Marginal Fit ◽  
Mean Values ◽  
Nickel Chromium ◽  
Dental Prostheses ◽  
The Mean ◽  
Alloy Titanium ◽  
Alloy Cast

Precision fit of dental prostheses were compared between the four experimental groups of cast Ni-Cr alloy, cast titanium, milled titanium and milled zirconium by measuring and comparing the mean values of the marginal, axial, occlusal and overall coping-die gaps. The overall, axial and occlusal fit was most precise with the cast Ni-Cr alloy prosthesis. The biologically critical marginal fit was the most precise with the milled zirconium, thus suggesting that the copy-milled zirconia ceramic could serve as an alternative to the cast-metal prosthesis. The statistical variables, such as the groups and the regions, were in association with and had an interaction effect on the adaptability of the prostheses. The marginal gaps correlated with the axial gaps in the cast Ni-Cr alloy and milled titanium groups

scholarly journals In Vitro Fit and Cementation Resistance of Provisional Crowns for Single Implant-Supported Restorations

2015 ◽  
Vol 26 (5) ◽  
pp. 468-473 ◽  
Author(s):  
Izabela Cristina Maurício Moris ◽  
Juliana Elias de Oliveira ◽  
Adriana Cláudia Lapria Faria ◽  
Ricardo Faria Ribeiro ◽  
Renata Cristina Silveira Rodrigues
Keyword(s):  
Film Thickness ◽  
Methyl Methacrylate ◽  
Calcium Hydroxide ◽  
Testing Machine ◽  
Mixed Linear Model ◽  
Marginal Fit ◽  
Luting Agents ◽  
Mechanical Cycling ◽  
Before And After

Abstract: This study aimed to verify marginal fit and the effect of cement film thickness standardization on retention of provisional crowns made with prefabricated acrylic cylinders on abutments, using two temporary luting agents subjected or not to mechanical cycling. Provisional crowns were made from bis-acryl (Luxatemp Fluorescence) or methyl methacrylate (Duralay) resins on acrylic cylinders and marginal fit and cement film thickness were evaluated. For retention evaluation, crowns were cemented with two temporary luting agents: non-eugenol zinc oxide (Tempbond NE) or calcium hydroxide-based (Hydcal) cements and subjected to tensile strength in a universal testing machine. After cleaning, debonded crowns were cemented again, subjected to mechanical cycling and retention was reassessed. The results of marginal fit and cement film thickness were analyzed by Student's t-test while retention of cements before and after mechanical cycling was analyzed using a mixed linear model. Methyl methacrylate crowns presented greater marginal misfit (p=0.001) and occlusal cement film thickness (p=0.003) than the bis-acryl ones. No difference was observed at axial cement film thickness (p=0.606). Resins (p=0.281) did not affect crown retention, but luting agents (p=0.029) and mechanical cycling (p=0.027) showed significant effects. The only significant interaction was mechanical cycling*luting agents, which means that luting agents were differently affected by mechanical cycling (p=0.002). In conclusion, the results showed that bis-acryl resin associated to calcium-hydroxide luting agent provided the best retention and lower cement thickness.

scholarly journals The Effect of Artificial Aging on The Bond Strength of Heat-activated Acrylic Resin to Surface-treated Nickel-chromium-beryllium Alloy

2016 ◽  
Vol 10 (1) ◽  
pp. 124-130
Author(s):  
Youssef S. Al Jabbari ◽  
Spiros Zinelis ◽  
Sara M. Al Taweel ◽  
William W. Nagy
Keyword(s):  
Acrylic Resin ◽  
Surface Treatments ◽  
Denture Base ◽  
Nickel Chromium ◽  
Before And After ◽  
Base Resin ◽  
Bond Strengths ◽  
Bonding Systems ◽  
Denture Base Resin ◽  
Debonding Load

Purpose The debonding load of heat-activated polymethylmethacrylate (PMMA) denture base resin material to a nickel-chromium-beryllium (Ni-Cr-Be) alloy conditioned by three different surface treatments and utilizing two different commercial bonding systems was investigated. Materials and Methods Denture resin (Lucitone-199) was bonded to Ni-Cr-Be alloy specimens treated with Metal Primer II, the Rocatec system with opaquer and the Rocatec system without opaquer. Denture base resin specimens bonded to non-treated sandblasted Ni-Cr-Be alloy were used as controls. Twenty samples for each treatment condition (80 specimens) were tested. The 80 specimens were divided into two categories, thermocycled and non-thermocycled, containing four groups of ten specimens each. The non-thermocycled specimens were tested after 48 hours’ storage in room temperature water. The thermocycled specimens were tested after 2,000 cycles in 4°C and 55°C water baths. The debonding load was calculated in Newtons (N), and collected data were subjected by non parametric test Kruskal-Wallis One Way Analysis of Variance on Ranks and Dunn’s post hoc test at the α = 0.05. Results The Metal Primer II and Rocatec system without opaquer groups produced significantly higher bond strengths (119.9 and 67.6 N), respectively, than did the sandblasted and Rocatec system with opaquer groups, where the bond strengths were 2.6 N and 0 N, respectively. The Metal Primer II was significantly different from all other groups (P<0.05). The bond strengths of all groups were significantly decreased (P<0.05) after thermocycling. Conclusions Although thermocycling had a detrimental effect on the debonding load of all surface treatments tested, the Metal Primer II system provided higher values among all bonding systems tested, before and after thermocycling.

scholarly journals Study on the Self-Organization of an Fe-Mn-C-B Coating during Friction with Surface-Active Lubricant

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3025 ◽  
Author(s):  
Marcin Barszcz ◽  
Mykhaylo Pashechko ◽  
Krzysztof Dziedzic ◽  
Jerzy Jozwik
Keyword(s):  
Friction Pair ◽  
Self Organization ◽  
Sliding Velocity ◽  
Laminar Structure ◽  
Friction Process ◽  
Nickel Chromium ◽  
Before And After ◽  
Pin On Disc ◽  
Surface Active ◽  
Sliding Distance

This paper investigates the friction process between an Fe-based coating and C45 steel with surface-active lubrication, as well as examines the coating surface before and after tribological testing. As a result, it is possible to determine whether the surface undergoes self-organization during friction. Coatings were produced by hardfacing a subeutectic alloy Fe-Mn-C-B modified by silicon, nickel, chromium and copper. Tribological tests were performed using a pin-on-disc tribometer. The pin (coating) and the disc made of steel C45 were subjected to heat treatment (hardening and tempering). The tests were carried out under loads of 3 MPa, 7 MPa and 10 MPa at a constant sliding velocity of 0.4 m/s and a sliding distance of 5700 m using a surface-active lubricant (glycerine oil). Obtained results were compared with the published results of previous tests carried out under the same conditions but under a load of 20 MPa. Obtained microscopic and spectroscopic results demonstrate that that the friction pair materials (the coating made of subeutectic alloy Fe-Mn-C-B modified by Si, Ni, Cr, Cu and C45 steel) and the surface-active lubricant cause self-organization during friction. The friction surface of the coatings has a flay-laminar structure and is covered with triboreaction products. The surface shows the presence of wear-resistant compounds such as oxides, carbides, borides and nitrides.

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