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.

scholarly journals A New Method to Evaluate Trueness and Precision of Digital and Conventional Impression Techniques for Complete Dental Arch

2021 ◽  
Vol 11 (10) ◽  
pp. 4612
Author(s):  
KweonSoo Seo ◽  
Sunjai Kim
Keyword(s):  
Intraclass Correlation ◽  
Three Dimensional ◽  
New Method ◽  
Digital Impression ◽  
Dental Arch ◽  
Digital Models ◽  
Digital Impressions ◽  
Measuring Machine ◽  
Master Model ◽  
Conventional Impression

Purpose: The aim of this study was to present a new method to analyze the three-dimensional accuracy of complete-arch dental impressions and verify the reliability of the method. Additionally, the accuracies of conventional and intraoral digital impressions were compared using the new method. Methods: A master model was fabricated using 14 milled polyetheretherketone cylinders and a maxillary acrylic model. Each cylinder was positioned and named according to its corresponding tooth position. Twenty-five definitive stone casts were fabricated using conventional impressions of the master model. An intraoral scanner was used to scan the master model 25 times to fabricate 25 digital models. A coordinate measuring machine was used to physically probe each cylinder in the master model and definitive casts. An inspection software was used to probe cylinders of digital models. A three-dimensional part coordinate system was defined and used to compute the centroid coordinate of each cylinder. Intraclass correlation coefficient (ICC) was evaluated to examine the reliability of the new method. Independent two sample t-test was performed to compare the trueness and precision of conventional and intraoral digital impressions (α = 0.05). Results: ICC results showed that, the new method had almost perfect reliability for the measurements of the master model, conventional and digital impression. Conventional impression showed more accurate absolute trueness and precision than intraoral digital impression for most of the tooth positions (p < 0.05). Conclusions: The new method was reliable to analyze the three-dimensional deviation of complete-arch impressions. Conventional impression was still more accurate than digital intraoral impression for complete arches.

scholarly journals Clinical Acceptability of the Internal Gap of CAD/CAM PD-AG Crowns Using Intraoral Digital Impressions

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Tae-Gyung Kim ◽  
Sungtae Kim ◽  
Hyunmin Choi ◽  
Jae-Hoon Lee ◽  
Jae-Hong Kim ◽  
...  
Keyword(s):  
Digital Impression ◽  
Digital Impressions ◽  
Significant Difference ◽  
Cad Cam ◽  
Cast Group ◽  
Group 10 ◽  
Internal Gap ◽  
Conventional Impression ◽  
Palladium Silver

The purpose of this study was to compare the internal gap between CAD/CAM palladium-silver crowns and cast gold crowns generated from intraoral digital versus conventional impressions and to determine the clinical acceptability. Nickel-chrome master dies were made from the prepared resin tooth with the conventional impression method (n=40). For ICC (Intraoral, CAD/CAM) group, 10 intraoral digital impressions were made, and 10 CAD/CAM crowns of a PD-AG (palladium-silver) machinable alloy were generated. For IC (Intraoral, Cast) group, 10 gold crowns were cast from ten intraoral digital impressions. For CCC (Conventional, CAD/CAM) group, 10 CAD/CAM PD-AG crowns were made using the conventional impression method. For CC (Conventional, Cast) group, 10 gold crowns were fabricated from 10 conventional impressions. One hundred magnifications of the internal gaps of each crown were measured at 50 points with an optical microscope and these values were statistically analyzed using a two-way analysis of variance (α=0.05). The internal gap of the intraoral digital impression group was significantly larger than in the conventional impression group (P<0.05). No significant difference was observed between the CAD/CAM group and the cast group (P>0.05). Within the limitations of this in vitro study, crowns from intraoral digital impressions showed larger internal gap values than crowns from conventional impressions.

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 CONVENTIONAL VS DIGITAL IMPRESSION TECHNIQUE FOR MANUFACTURING OF THREE-UNIT ZIRCONIA BRIDGES: CLINICAL TIME EFFICIENCY

2021 ◽  
Vol 27 (2) ◽  
pp. 3765-3771
Author(s):  
Kiril Gogushev ◽  
◽  
Metodi Abadjiev ◽  
Keyword(s):  
Soft Tissues ◽  
Digital Impression ◽  
Controlled Clinical Trial ◽  
Dental Arch ◽  
Manufacturing Companies ◽  
Impression Technique ◽  
Impression Materials ◽  
Digital Impressions ◽  
Time Required ◽  
Conventional Impression

Introduction: Taking an impression of the oral cavity, which accurately recreates the prosthetic field, the surrounding hard dental and soft tissues, is one of the main and most important stages in the process of making any fixed prosthetic restoration. In modern prosthetic dentistry, impressions taken with the help of polyether and vinyl polysiloxane impression materials are common. Digital impressions eliminate some of the steps of conventional impression techniques and save clinical time. Aim: The aim of this article is to compare the clinical time in digital and conventional impression techniques from a whole dental arch using a controlled clinical trial. Material and methods: The present study includes 36 patients from Varna who need prosthetic treatment with fixed 3-unit bridge construction. For all participants, the conventional impression technique was performed first and one week later - the digital one. All clinical manipulations related to the implementation of the two impression techniques were performed according to the instructions of the manufacturing companies by the same specialist dentist. Results: In all participants, the time required to perform the digital impression technique is significantly less than that of the conventional impression technique. Conclusion: The digital impression technique has proven to be more efficient in terms of clinical time required for its implementation than the conventional impression 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.

Evaluation of Mechanical Properties of Dental Feldsphatic Porcelains for Metal and Zirconia Core

2012 ◽  
Vol 727-728 ◽  
pp. 1104-1107
Author(s):  
Antonio Alves de Almeida-Junior ◽  
Gelson Luis Adabo ◽  
Beatriz Regalado Galvão ◽  
Diogo Longhini ◽  
Claudinei dos Santos
Keyword(s):  
Fracture Toughness ◽  
Flexural Strength ◽  
Vickers Hardness ◽  
High Hardness ◽  
Hardness Test ◽  
Dental Prostheses ◽  
Significant Incidence ◽  
Significant Difference ◽  
Fixed Dental Prostheses ◽  
Intermediate Value

Studies has been reported a significant incidence of chipping of the feldspathic porcelain veneer in zirconia-based restorations. The purpose of this study was to compare the three-point flexural strength (MPa), Weibull parameters, Vickers hardness (VHN) and Vickers indentation fracture toughness (MPa/mm1/2) in feldspatic porcelains for metal and for zirconia frameworks. Bar specimens were made with the porcelains e.MaxCeram (EM) and VitaVM9 (V9) for zirconia core, and Duceragold (DG) and VitaVMK95 (VK) for metal core (n= 15). Kruskal-Wallis and Dun test were used for statistical analysis. There was no significant difference (p=0.31) among the porcelains in the flexural strength (Median= 73.2; 74.6; 74.5; 74.4). Weibull calculation presented highest reliability for VK (10.8) followed by EM (7.1), V9 (5.7) and DG (5.6). Vickers hardness test showed that EM (536.3), V9 (579.9) and VK (522.1) had no difference and DG (489.6) had the lowest value (p.001). The highest fracture toughness was to VK (1.77), DG (1.58) had an intermediate value while V9 (1.33) and EM (1.18) had the lowest values (p.001). Despite of the suitable flexural strength, reliability and high hardness, the porcelains used to zirconia-based fixed dental prostheses showed lower fracture toughness values.

scholarly journals Computerized Casts for Orthodontic Purpose Using Powder-Free Intraoral Scanners: Accuracy, Execution Time, and Patient Feedback

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Maria Francesca Sfondrini ◽  
Paola Gandini ◽  
Maurizio Malfatto ◽  
Francesco Di Corato ◽  
Federico Trovati ◽  
...  
Keyword(s):  
Computer Software ◽  
Digital Impression ◽  
Processing Times ◽  
Patient Feedback ◽  
Intraoral Scanning ◽  
Digital Impressions ◽  
Titanium Dioxide Powder ◽  
Dioxide Powder ◽  
Digital Scanning ◽  
Conventional Impression

Introduction. Intraoral scanners allow direct images of oral situation, with fewer steps than conventional impressions. The purpose of this study was to compare the accuracy of digital impressions, traditional impressions, and digitalization of full-arch gypsum models, to evaluate timing of different methods and finally to study perception of patients about conventional and digital impression techniques. Methods. Dental arches of fourteen patients were evaluated by alginate impression, titanium dioxide powder-free intraoral scanning (Trios, 3Shape), and digitalization obtained from gypsum models using the same scanner. Conventional and digital techniques were evaluated through measurements (lower and upper arch anteroposterior length, lower and upper intercanine distance, and lower and upper intermolar distance) with a caliber for analogic models and using a computer software for digital models (Ortho Analyzer, Great Lakes Orthodontics). In addition, chairside and processing times were recorded. Finally, each patient completed a VAS questionnaire to evaluate comfort. Statistical analyses were performed with ANOVA and Tukey tests for accuracy measurements and paired t-test for times and VAS scores. Significance was predetermined at P<0.05. Results. The measurements obtained with intraoral scanning, gypsum models after conventional impression, and digitalized gypsum models were not significantly different. Both chairside and processing times of digital scanning were shorter than the traditional method. VAS reporting patients comfort were significantly higher when evaluating digital impression. Conclusions. Intraoral scanners used for orthodontic applications provide useful data in clinical practice, comparable to conventional impression. This technology is more time efficient than traditional impression and comfortable for patients. Further evolution with more accurate and faster scanners could in future replace traditional impression methods.

Dimensional Accuracy of Working Dies Fabricated by Different Impression Materials and Techniques: 3D Digital Assessment

2021 ◽  
Vol 11 (1) ◽  
pp. 106-111
Author(s):  
Mai Soliman ◽  
Alhanoof Aldegheishem ◽  
Norah Alsubaie ◽  
Razan Alshamrani ◽  
Elzahraa Eldwakhly
Keyword(s):  
Dimensional Accuracy ◽  
Molar Tooth ◽  
3D Scanner ◽  
Impression Material ◽  
Four Dimensions ◽  
Digital Assessment ◽  
Impression Materials ◽  
Significant Difference ◽  
Gingival Dimensions ◽  
One Step

Accuracy of dental impression plays a significant role in the success of definitive restorations. This study aimed to compare the dimensional accuracy of working dies fabricated using two different impression materials and techniques. Forty working dies fabricated from 40 impressions of preprepared mandibular first molar tooth replica stabilized in a jaw model to receive full coverage crown. Two different Polyvinyl siloxane (PVS) impression materials were used; Aquasil and Virtual. Two different impression techniques were used with each type of impression material; One-step and two-step. The working dies dimensional accuracy was measured in four dimensions and compared with that of the preprepared molar tooth replica using a digital caliper and 3D scanner. Based on a 3D scanner, there were a significant difference of dies fabricated by the two tested impression materials using the two-step impression technique in Mesiodistal-Gingival dimension (IIA and IIB) groups compared to the preprepared tooth replica with an average 0.370 μm (P < .005). A significant difference was observed of the dies fabricated by the two tested impression techniques using virtual impression. material in Mesiodistal Occlusal dimensions with an average 0.135 μm (P < .03), and in Mesiodistal-Gingival dimensions with an average 0.490 μm (P < .001) and Buccolingual-Gingival dimensions with an average 0.143 μm (P < .005) using Aquasil impression material compared to the preprepared molar tooth replica. Both impression materials (Aquasil and Virtual) and techniques (One-step and Two-step) used in this study produced working dies with clinically accepted dimensional accuracy.

scholarly journals Use of digital impression systems with intraoral scanners for fabricating restorations and fixed dental prostheses

2018 ◽  
Vol 60 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Yoshimasa Takeuchi ◽  
Hiroyasu Koizumi ◽  
Mika Furuchi ◽  
Yohei Sato ◽  
Chikahiro Ohkubo ◽  
...  
Keyword(s):  
Digital Impression ◽  
Dental Prostheses ◽  
Fixed Dental Prostheses
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