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

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.

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

Journal of IMAB - Annual Proceeding (Scientific Papers) ◽

10.5272/jimab.2021272.3765 ◽

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.

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Digital versus Conventional Impression Taking Focusing on Interdental Areas: A Clinical Trial

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17134725 ◽

2020 ◽

Vol 17 (13) ◽

pp. 4725

Author(s):

Maximiliane Amelie Schlenz ◽

Victoria Schubert ◽

Alexander Schmidt ◽

Bernd Wöstmann ◽

Sabine Ruf ◽

...

Keyword(s):

Clinical Trial ◽

Three Dimensional ◽

Digital Impression ◽

P Value ◽

Digital Impressions ◽

High Prevalence ◽

The Absolute ◽

True Definition ◽

Conventional Impression ◽

Tooth Migration

Due to the high prevalence of periodontitis, dentists have to face a larger group of patients with periodontally compromised dentitions (PCDs) characterized by pathologic tooth migration and malocclusion. Impression taking in these patients is challenging due to several undercuts and extensive interdental areas (IAs). The aim of this clinical trial was to analyze the ability of analog and digital impression techniques to display the IAs in PCDs. The upper and the lower jaws of 30 patients (n = 60, age: 48–87 years) were investigated with one conventional impression (CVI) using polyvinyl siloxane and four digital impressions with intraoral scanners (IOSs), namely True Definition (TRU), Primescan (PRI), CS 3600 (CAR), and TRIOS 3 (TIO). The gypsum models of the CVIs were digitalized using a laboratory scanner. Subsequently, the percentage of the displayed IAs in relation to the absolute IAs was calculated for the five impression techniques in a three-dimensional measuring software. Significant differences were observed among the impression techniques (except between PRI and CAR, p-value < 0.05). TRU displayed the highest percentage of IAs, followed by PRI, CAR, TIO, and CVI. The results indicated that the IOSs are superior to CVI regarding the ability to display the IAs in PCDs.

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

Applied Sciences ◽

10.3390/app112412034 ◽

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.

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

BioMed Research International ◽

10.1155/2016/7065454 ◽

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.

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Evaluation of the Accuracy of Four Digital Methods by Linear and Volumetric Analysis of Dental Impressions

Materials ◽

10.3390/ma12121958 ◽

2019 ◽

Vol 12 (12) ◽

pp. 1958 ◽

Cited By ~ 12

Author(s):

Stefano Pagano ◽

Michele Moretti ◽

Roberto Marsili ◽

Alessandro Ricci ◽

Giancarlo Barraco ◽

...

Keyword(s):

Probability Distributions ◽

Three Dimensional ◽

Point Clouds ◽

Volumetric Analysis ◽

Digital Impression ◽

Dental Arch ◽

Mean Values ◽

Coordinate Measurement ◽

Dental Clinics ◽

Accuracy And Precision

The quality of dental arch impression has a substantial role in the precision of the intervention. It is traditionally acquired with resins that solidify when in contact with the air. Compared to that method, digital impression gives great advantages and, together with three-dimensional (3D) digitization devices, allows a simplification of the digital impression process. The growing adoption of such systems by a large number of dental clinics determines the need for an in-depth evaluation of the accuracy and the precision of the different systems. The aim of this work is to define a methodology for the evaluation of the accuracy and precision of 3D intraoral and desktop scanning systems, by using volumetric and linear methods. The replica of a tooth was realized with zirconium; afterward, high-accuracy point clouds of the master model were acquired by a coordinate measurement machine (CMM). In this way, the dimensions of the replica were accurately known. An intraoral scanner (I) and three desktops (D1, D2, D3) were then used to scan the replica. The geometry resulting from the CMM was compared with the ones derived from the scanners, using two different commercial programs (Geomagic and 3-Matic) and a custom-developed algorithm (MATLAB). Geomagic showed the mean values to be in a range from 0.0286 mm (D1) to 0.1654 mm (I), while 3-Matic showed mean values from −0.0396 mm (D1) to 0.1303 mm (I). MATLAB results ranged from 0.00014 mm (D1) to 0.00049 mm (D2). The probability distributions of the volumetric error of the measurements obtained with the different scanners allow a direct comparison of their performances. For the results given by our study, the volumetric approach that we adopted appears to be an excellent system of analysis.

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Digital Intraoral Scanners and Alginate Impressions in Reproducing Full Dental Arches: A Comparative 3D Assessment

Applied Sciences ◽

10.3390/app10217637 ◽

2020 ◽

Vol 10 (21) ◽

pp. 7637

Author(s):

Kyungmin Clara Lee ◽

Seong-Joon Park

Keyword(s):

Surface Analysis ◽

Three Dimensional ◽

Dental Arch ◽

Posterior Teeth ◽

Average Surface ◽

3D Surface ◽

Surface Deviations ◽

Scan Data ◽

Conventional Impression

The purpose of this in vivo study was to compare in vivo full arch intraoral scans obtained using two intraoral scanners and conventional impression. Twenty patients were scanned using TRIOS and iTero scanners, as well as conventional impression. Dental models obtained from alginate impression were scanned with a laboratory desktop scanner. Individual intraoral scan data were compared with corresponding model scans using three-dimensional (3D) surface analysis. The average surface deviations were calculated for quantitative evaluation, and these values were compared between two intraoral scanners using the paired t-test. In the 3D surface analysis, most deviations between intraoral scans and model scans presented on the posterior teeth. The average surface deviations were less than 0.10 ± 0.03 mm. The results of 3D surface analysis indicated that there was 0.10 mm of overall deviation between conventional alginate impressions and in vivo full dental arch intraoral scans. Clinicians should take this into consideration when performing intraoral scanning for full dental arches.

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An exact method for the sphericity measurement of soccer balls

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1243/095440503322011452 ◽

2003 ◽

Vol 217 (5) ◽

pp. 715-719 ◽

Cited By ~ 6

Author(s):

P J Neilson ◽

R Jones

Keyword(s):

Three Dimensional ◽

Computer Software ◽

Coordinate Measuring Machine ◽

Current Method ◽

New Method ◽

Ball Surface ◽

Ball Diameter ◽

Sphere Approximation ◽

Measuring Machine ◽

A New Technique

The most popular games in the world are ball sports. Generally, ball properties such as weight, circumference and sphericity are specified in the rules and determine the ball quality. The current method of sphericity measurement employed by the Federation International Football Association (FIFA) is to measure the ball diameter at 16 points and then calculate the mean average. The sphericity of the ball is inferred from the diametric measurements. Unfortunately, diameter measurement does not guarantee sphericity, and a new technique has been developed to measure ball sphericity using a coordinate measuring machine (CMM). In this method a representative sample of the ball surface is probed/measured to give three-dimensional coordinates of defined points, nominally the ball panel centres. Computer software is then used to fit a least-squares sphere approximation to the ball data, giving a unique value for ball sphericity. Measurements were taken of six different brand type balls, with a sample of four balls of each brand; all balls were inflated to the same pressure. The results show that the new method of sphericity measurement suggested here gives a unique assessment of sphericity. The errors obtained from the new method are such that the FIFA error specification may need reconsideration.

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

BioMed Research International ◽

10.1155/2018/4103232 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8 ◽

Cited By ~ 25

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.

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The Evaluation of Working Casts Prepared from Digital Impressions

Operative Dentistry ◽

10.2341/12-352-l ◽

2013 ◽

Vol 38 (6) ◽

pp. 655-662 ◽

Cited By ~ 11

Author(s):

YC Hwang ◽

YS Park ◽

HK Kim ◽

YS Hong ◽

JS Ahn ◽

...

Keyword(s):

Measurement Error ◽

Rapid Prototyping ◽

Correlation Coefficient ◽

Intraclass Correlation ◽

Digital Impression ◽

Milling Machine ◽

Intraoral Scanner ◽

Digital Impressions ◽

Milling Machines ◽

Excellent Reproducibility

SUMMARY Objective The aim of this study is to evaluate the reproducibility of working casts of a digital impression system by comparing them with the original, virtual, and rapid prototyping casts. Materials and Methods A total of 54 cast sets in clinically stable occlusion were used. They were scanned by an iTero intraoral scanner and converted into STL format virtual casts. Rapid prototyping casts and polyurethane casts were fabricated from the iTero milling system based on the virtual casts. Several horizontal and vertical measurements were performed from the four types of casts, that is, original stone casts, virtual casts, rapid prototyping casts, and polyurethane casts of iTero. Measurement error, intraclass correlation coefficient (ICC), and differences among the casts were calculated and compared. Results Casts from iTero milling machines exhibited greater dimensional differences and lower ICC values than did other casts. In addition, many of the measurements of the iTero working casts showed statistically significant differences in comparison to the three other types of casts. In contrast, there were no statistically significant differences between the virtual and original casts. Conclusion Virtual casts made by the iTero intraoral scanner exhibited excellent reproducibility. However, the casts from the iTero milling machine showed greater dimensional differences and lower reproducibility compared to other types of casts.

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