scholarly journals Marginal and Internal Fit of Cobalt-Chromium Fixed Dental Prostheses Generated from Digital and Conventional Impressions

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Per Svanborg ◽  
Henrik Skjerven ◽  
Pablo Carlsson ◽  
Alf Eliasson ◽  
Stig Karlsson ◽  
...  
Keyword(s):  
Digital Impression ◽  
Cobalt Chromium ◽  
Marginal Gap ◽  
Impression Material ◽  
Dental Prostheses ◽  
Digital Impressions ◽  
Fixed Dental Prostheses ◽  
Internal Fit ◽  
Cervical Area ◽  
Scan Protocol

Objectives. Digital impressions are increasingly used and have the potential to avoid the problem of inaccurate impressions. Only a few studies to verify the accuracy of digital impressions have been performed. The purpose of this study was to compare the marginal and internal fit of 3-unit tooth supported fixed dental prostheses (FDPs) fabricated from digital and conventional impressions.Methods. Ten FDPs were produced from digital impressions using the iTero system and 10 FDPs were produced using vinyl polysiloxane (VPS) impression material. A triple-scan protocol and CAD software were used for measuring and calculating discrepancies of the FDPs at 3 standard areas: mean internal discrepancy, absolute marginal gap, and cervical area discrepancy. The Mann-Whitney U test was used for analyzing the results.Results. For conventional and digital impressions, respectively, FDPs had an absolute marginal gap of 147 μm and 142 μm, cervical area discrepancy of 69 μm and 44 μm, and mean internal discrepancy of 117 μm and 93 μm. The differences were statistically significant in the cervical and internal areas (P<0.001).Significance. The results indicated that the digital impression technique is more exact and can generate 3-unit FDPs with a significantly closer fit compared to the VPS technique.

scholarly journals Assessment of Fit on Ten Screw-Retained FrameworksRealized through Digital Full-Arch Implant Impression

2021 ◽  
Vol 11 (12) ◽  
pp. 5617
Author(s):  
Maurizio De Francesco ◽  
Edoardo Stellini ◽  
Stefano Granata ◽  
Sergio Mazzoleni ◽  
Francesco Saverio Ludovichetti ◽  
...  
Keyword(s):  
Surgical Procedure ◽  
Test Methods ◽  
Digital Impression ◽  
Rank Test ◽  
Microscope Examination ◽  
Dental Prostheses ◽  
Digital Impressions ◽  
Fixed Dental Prostheses ◽  
The Mean ◽  
Master Model

Background: Discordant opinions have emerged among clinicians and researchers regarding a digital impression for full-arch implant-supported fixed dental prostheses (FDPs). The purpose of this study was to assess the fit of screw-retained milled frameworks on six implants realized from digital impressions through the Sheffield test. Methods: One patient received a maxillary full-arch implant-supported FDP. Six months after the surgical procedure, ten intraoral full-arch digital impressions were performed to mill ten frameworks. To clinically assess the fit, the Sheffield test was applied for all frameworks. The gaps among the frameworks and the implant analogs were measured using a microscope on the master model realized with a traditional impression. The Wilcoxon sum-rank test was used to compare the misfit value among the different implant positions. Results: The Sheffield test did not show gaps in the framework–implant interfaces when the screw was completely tightened on the more distal implant for all the milled frameworks. The mean misfit value calculated after microscope examination was 38 ± 5 μm. Differences that were statistically significant emerged when the misfit values of central positions were compared with other values. Conclusions: The use of full-arch implant digital impressions represents a viable alternative to traditional impressions for the fabrication of implant-supported FDPs.

scholarly journals Accuracy of Master Casts Generated Using Conventional and Digital Impression Modalities: Part 1—The Half-Arch Dimension

2021 ◽  
Vol 11 (24) ◽  
pp. 12034
Author(s):  
Mohammed E. Sayed ◽  
Abdulkarim Hussain Alshehri ◽  
Bandar M. A. Al-Makramani ◽  
Fuad Al-Sanabani ◽  
Fawzia Ibraheem Shaabi ◽  
...  
Keyword(s):  
Digital Impression ◽  
Digital Models ◽  
Four Dimensions ◽  
Dental Prostheses ◽  
Impression Materials ◽  
Digital Impressions ◽  
Significant Difference ◽  
Alternative Materials ◽  
Fixed Dental Prostheses ◽  
Conventional Impression

Accurate impression-making is considered a vital step in the fabrication of fixed dental prostheses. There is a paucity of studies that compare the casts generated by various impression materials and techniques that are commonly used for the fabrication of provisional and definitive fixed prostheses. The aim of this study is to compare the accuracy of casts obtained using conventional impression and digital impression techniques. Thirty impressions were made for the typodont model (10 impressions each of polyvinyl siloxane, alginate, and alginate alternative materials). Ten digital models were printed from the same model using a TRIOS-3 3Shape intraoral scanner. Accuracy was assessed by measuring four dimensions (horizontal anteroposterior straight, horizontal anteroposterior curved, horizontal cross-arch, and vertical). A one-way ANOVA and Tukey’s test (α = 0.05) were used to analyze data. A statistically significant difference in the four dimensions of the stone casts and digital models was observed among the four groups (exception: between alginate alternative and 2-step putty–light body impression in the horizontal anteroposterior straight, horizontal anteroposterior curved, and horizontal cross-arch dimensions; between alginate and alginate alternative in the horizontal anteroposterior curved dimension; between alginate and 2-step putty–light body impression in the horizontal anteroposterior curved dimension; and between alginate alternative and digital in the vertical dimension). Polyvinyl siloxane had the highest accuracy compared to casts obtained from other impression materials and digital impressions.

A 5-Year Retrospective Study of Cobalt-Chromium–Based Fixed Dental Prostheses

2013 ◽  
Vol 26 (4) ◽  
pp. 343-349 ◽  
Author(s):  
Per Svanborg ◽  
Lena Längström ◽  
Ritva Moisio Lundh ◽  
Göran Bjerkstig ◽  
Anders Örtorp
Keyword(s):  
Retrospective Study ◽  
Cobalt Chromium ◽  
Dental Prostheses ◽  
Fixed Dental Prostheses

scholarly journals A Comparison Study of Marginal and Internal Fit Assessment Methods for Fixed Dental Prostheses

2019 ◽  
Vol 8 (6) ◽  
pp. 785 ◽  
Author(s):  
Keunbada Son ◽  
Sangbong Lee ◽  
Seok Hyon Kang ◽  
Jaeseok Park ◽  
Kyu-Bok Lee ◽  
...  
Keyword(s):  
Assessment Methods ◽  
Comparison Study ◽  
Micro Computed Tomography ◽  
Replica Technique ◽  
Cross Sectional ◽  
Mean Values ◽  
Axial Angle ◽  
Dental Prostheses ◽  
Fixed Dental Prostheses ◽  
Internal Fit

Numerous studies have previously evaluated the marginal and internal fit of fixed prostheses; however, few reports have performed an objective comparison of the various methods used for their assessment. The purpose of this study was to compare five marginal and internal fit assessment methods for fixed prostheses. A specially designed sample was used to measure the marginal and internal fit of the prosthesis according to the cross-sectional method (CSM), silicone replica technique (SRT), triple scan method (TSM), micro-computed tomography (MCT), and optical coherence tomography (OCT). The five methods showed significant differences in the four regions that were assessed (p < 0.001). The marginal, axial, angle, and occlusal regions showed low mean values: CSM (23.2 µm), TSM (56.3 µm), MCT (84.3 µm), and MCT (102.6 µm), respectively. The marginal fit for each method was in the range of 23.2–83.4 µm and internal fit (axial, angle, and occlusal) ranged from 44.8–95.9 µm, 84.3–128.6 µm, and 102.6–140.5 µm, respectively. The marginal and internal fit showed significant differences depending on the method. Even if the assessment values of the marginal and internal fit are found to be in the allowable clinical range, the differences in the values according to the method should be considered.

Internal and marginal fit of cobalt-chromium fixed dental prostheses fabricated with 3 different techniques

2015 ◽  
Vol 114 (5) ◽  
pp. 686-692 ◽  
Author(s):  
Harald Nesse ◽  
Dina Mari Åkervik Ulstein ◽  
Malene Myhre Vaage ◽  
Marit Øilo
Keyword(s):  
Cobalt Chromium ◽  
Marginal Fit ◽  
Dental Prostheses ◽  
Fixed Dental Prostheses
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