The Evaluation of Working Casts Prepared from Digital Impressions

2013 ◽  
Vol 38 (6) ◽  
pp. 655-662 ◽  
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.

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.

Digital Impression taking for Maxillary Full-Arch Restoration with Immediate Loading. A Case Report.

2021 ◽  
Author(s):  
Jesús Peláez Rico ◽  
Jorge Cortés-Bretón Brinkmann ◽  
María Carrión Martín ◽  
Mabel Albanchez González ◽  
Celia Tobar Arribas ◽  
...  
Keyword(s):  
Acrylic Resin ◽  
Digital Impression ◽  
Immediate Loading ◽  
Clinical Report ◽  
Intraoral Scanner ◽  
Intraoral Scanning ◽  
Digital Impressions ◽  
Removable Prosthesis ◽  
And Function

The aim of this clinical report is to describe a maxillary full-arch implant supported restoration with immediate loading performed by means of an entirely digital workflow with photogrammetric system and intraoral scanning. A female patient with an edentulous maxillary arch attended the dental clinic seeking a maxillary fixed restoration. After treatment planning, six implants were placed using a surgical splint fabricated digitally by intraoral scanning of her previous removable prosthesis. Multi-unit abutments were fitted and two digital impressions were taken, one with a photogrammetric system for determining implant positions, and the other with an intraoral scanner for soft tissue registration. The acrylic resin structure of the immediate prosthesis was milled and placed within 8 hours of implant surgery. This provisional structure fitted correctly and provided adequate esthetics and function. Radiographic and clinical follow-up after 24 months observed adequate implant evolution.

scholarly journals Intra-rater reliability of transversus abdominis measurement by a novice examiner: Comparison of “freehand” to “probe force device” method of real-time ultrasound imaging

Ultrasound ◽  
2019 ◽  
Vol 27 (3) ◽  
pp. 156-166 ◽  
Author(s):  
Vanessa L Kennedy ◽  
Carol A Flavell ◽  
Kenji Doma
Keyword(s):  
Measurement Error ◽  
Real Time ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Coefficient Of Variation ◽  
Repeated Measures ◽  
Intraclass Correlation ◽  
Transversus Abdominis ◽  
Rater Reliability ◽  
Transverse Abdominis

A “free hand” real-time-ultrasound method is commonly applied to measure transversus abdominis. Potentially, this increases transversus abdominis measurement error due to uncontrolled variability in probe to skin force, inclination, and roll, particularly for novice examiners. This single-group repeated-measures reliability study compared the intra-rater reliability of transversus abdominis thickness and activation measurement by a novice examiner between free hand and a standardized probe force device method. The examiner captured ultrasound videos of transversus abdominis in a single session in healthy participants ( n =  33). Free hand ultrasound featured uncontrolled probe force, inclination, and roll, while probe force device method ultrasound standardized these parameters. Images of transversus abdominis at rest and contracted were measured and transversus abdominis activation calculated. Intraclass correlation coefficient, coefficient of variation, standard error of measurement, and worthwhile differences were calculated. The probe force device method resulted in greater reliability (intraclass correlation coefficient = 0.75–0.96) and lower measurement error (coefficient of variation = 8.89–28.7%) compared to free hand (intraclass correlation coefficient = 0.63–0.93; coefficient of variation = 6.52–29.4%). Reliability was good for all measurements except free hand TrA-C, which was moderate. TrA-C had the lowest reliability, followed by contracted thickness of the transverse abdominis, with resting thickness of the transverse abdominis being highest. Worthwhile differences were lower using a probe force device method versus free hand for resting thickness of the transverse abdominis and contracted thickness of the transverse abdominis and similar for TrA-C. Standardization using probe force device method ultrasound to measure transversus abdominis improved intra-rater reliability in a novice examiner. Use of a probe force device method is recommended to improve reliability through reduced sources of measurement error. Probe force device method intra- and inter-rater reliability in examiners of varying experience, in clinical populations, and to visualize other structures merits exploration.

Assessment of Scapular Position

1993 ◽  
Vol 2 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Lynne Neiers ◽  
Teddy W. Worrell
Keyword(s):  
Measurement Error ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Therapeutic Intervention ◽  
Intraclass Correlation ◽  
Accurate Method ◽  
Force Development ◽  
Experienced Clinician ◽  
Reliability Coefficients ◽  
Shoulder Musculature

Assessment of posture is an integral component of the evaluation of patients with neck and shoulder dysfunctions. Protraction of the scapulae has been postulated to produce weakness of the shoulder musculature. Therefore, an accurate method is needed to assess scapular position in order to determine the effect of therapeutic intervention and classify dysfunction. The purpose of this study was to determine if an experienced clinician would accurately determine scapular position. Fifty subjects (age = 26 ±5.7 years, weight = 69.2 ±14.09 kg; height = 173.9 ±13.91 cm) participated in this study. The results revealed the following reliability coefficients: scapular distance (SD) intraclass correlation coefficient (ICC) = .80, scapular size (SS) ICC = .96, and normalized scapular abduction (NSA) (SD/SS) ICC = .34. These data demonstrate that NSA was not reproducible in this study. The authors hypothesize that NSA contains more measurement error because NSA is a ratio value in which both the numerator and denominator contain measurement error. Further study is needed before NSA values are used to determine scapular position or correlated NSA is used to force development of shoulder musculature.

scholarly journals SPINE GUNSHOT WOUNDS AT THE CENTRAL MILITARY HOSPITAL IN MEXICO

2016 ◽  
Vol 15 (2) ◽  
pp. 134-139 ◽  
Author(s):  
ISAAC ENRIQUE HERNÁNDEZ TÉLLEZ ◽  
EDGARDO ALONSO MONTELONGO MERCADO ◽  
JESÚS JOSÉ ARREOLA BASTIDAS ◽  
EDUARDO LARRINÚA BETANCOURT ◽  
AVELINO AGUILAR MERLO
Keyword(s):  
Cobb Angle ◽  
Correlation Coefficient ◽  
Intraclass Correlation ◽  
Gunshot Wounds ◽  
Military Hospital ◽  
Average Change ◽  
Spine Surgeon ◽  
Cobb Method ◽  
Main Curve ◽  
Excellent Reproducibility

ABSTRACT Objective: To compare the measurement of the Cobb angle in printed radiographs and digitalized radiographs displayed with the "PixViewer" tool. Methods: Pre-operative radiographs of 23 patients were performed in printed films and using the software "PixViewer". The same evaluator, a spine surgeon, chose the proximal and distal end vertebrae at the limit of the main curve in printed radiographs without identifying patients, and measured the Cobb angle based on these parameters. The same parameters and measurements were performed in digitalized radiographs. The measurements were compared, as well as the choice of end vertebrae. Results: The average change in the Cobb angle between the methods was 1.48±1.73°. The intraclass correlation coefficient (ICC) was 0.99, demonstrating excellent reproducibility. Conclusion: The Cobb method can be used to evaluate scoliosis through the "PixViewer" tool with the same reliability of the classic method on printed radiographs.

scholarly journals Reliability of Isometric Lower-Extremity Muscle Strength Measurements in Children With Cerebral Palsy: Implications for Measurement Design

2013 ◽  
Vol 93 (7) ◽  
pp. 935-941 ◽  
Author(s):  
Lydia Willemse ◽  
Merel A. Brehm ◽  
Vanessa A. Scholtes ◽  
Laura Jansen ◽  
Hester Woudenberg-Vos ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Measurement Error ◽  
Muscle Strength ◽  
Lower Extremity ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Muscle Group ◽  
Children With Cerebral Palsy ◽  
Measurement Design

Background Children with cerebral palsy (CP) typically show muscle weakness of the lower extremities, which can be measured with the use of handheld dynamometry (HHD). Objective The purposes of this study were: (1) to determine test-retest reliability and measurement error of isometric lower-extremity strength measurements in children with CP with the use of HHD and (2) to assess implications for measurement design. Design A test-retest design was used. Methods Fourteen children with hemiplegic (n=6) or diplegic (n=8) spastic CP (Gross Motor Function Classification System levels I–III), ages 7 to 13 years, were assessed for isometric strength on 2 separate days (occasions) with the use of HHD, with 3 trials per muscle group. The intraclass correlation coefficient, standard error of measurement, and smallest detectable difference (SDD) were calculated for different measurement designs. Results Intraclass correlation coefficient values of single measurements for all muscle groups ranged from .70 to .90, and the SDD was large (&gt;30%). Regarding measurement error, the largest source of variability was found for occasion. A 2-occasion mean decreased the SDD by 9% to 14%. For trials, a greater improvement in SDD was found when 2 trials were averaged instead of 3. A measurement design of 2 trials–2 occasions was superior to the often-used approach of 3 trials–1 occasion. Limitations The small sample size was the major study limitation. Conclusions Handheld dynamometry is reliable and can be used to detect changes in isometric muscle strength in children with CP when using the mean of at least 2 trials. To further improve reliability, taking the average of 2 occasions on separate days is recommended, depending on group size and muscle group.

scholarly journals Three-dimensional Acetabular Bone Defect Classification System Aided with Rapid Prototyping Model and Reliability and Validity Test

2021 ◽  
Author(s):  
Jingwei Zhang ◽  
Yi Hu ◽  
Hua Ying ◽  
Yuanqing Mao ◽  
Zhenan Zhu ◽  
...  
Keyword(s):  
Rapid Prototyping ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Bone Defect ◽  
Intraclass Correlation ◽  
Three Dimensional ◽  
Revision Arthroplasty ◽  
Reliability And Validity ◽  
Defect Classification ◽  
Observer Reliability

Abstract Background: Accurately assessing acetabular defects and designing precise and feasible surgical plans are important before hip revision arthroplasty. With the development of three-dimensional printing, rapid prototyping is a novel technique used to print isometric physical object models. We aimed to propose a three-dimensional acetabular bone defect classification system aided with rapid prototyping and evaluated its reliability and validity.Methods: We reviewed 104 consecutive patients who underwent hip revision arthroplasty in our department between January 2014 and December 2019. Forty five of them had rapid prototyping and were included for reliability and validity test. Three doctors retrospectively evaluated bone defects of these 45 patients with this classification and made surgical plans, and repeated it after 2 weeks. The intra- and inter-observer reliability and the validity to surgical records were assessed using intraclass correlation coefficient or Kappa correlation coefficient.Results: The reliability and validity for classification results were high. The mean initial intraclass correlation coefficient for inter-observer reliability was 0.947, which increased to 0.972 when texted second time. As for inter-observer reliability, it ranged from 0.958 to 0.980. The validity showed high Kappa correlation coefficient of 0.951 to 0.967. When considering detailed surgical plans, the reliability and validity were also high with intraclass correlation coefficient and Kappa correlation coefficient all over 0.9.Conclusions: This three-dimensional acetabulum defect classification was of high reliability and convincing validity. With this classification and objective rapid prototyping models, accurate bone defect assessment and reliable surgical plans were achieved. This classification aided with rapid prototyping could serve as a promising tool for surgeons for preoperative evaluation.

scholarly journals Measurement error of self-paced exercise performance in athletic women is not affected by ovulatory status or ambient environment

2021 ◽  
Author(s):  
Huixin Zheng ◽  
Claire E. Badenhorst ◽  
Tze-Huan Lei ◽  
Ahmad Munir Che Muhamed ◽  
Yi-Hung Liao ◽  
...  
Keyword(s):  
Measurement Error ◽  
Correlation Coefficient ◽  
Intraclass Correlation ◽  
Oral Contraceptive Pill ◽  
Appreciable Effect ◽  
Ambient Conditions ◽  
Exercise Tests ◽  
Moderating Variables ◽  
Ambient Environment ◽  
Stress Studies

Measurement error(s) of exercise tests for women are severely lacking in the literature. The purpose of this investigation was to 1) determine whether ovulatory status or ambient environment were moderating variables when completing a 30-min self-paced work trial, and 2) provide test-retest norms specific to athletic women. A retrospective analysis of three heat stress studies was completed using 33 female participants (31±9 y, 54±10 mL min-1 kg-1) that yielded 130 separate trials. Participants were classified as ovulatory (n=19), anovulatory and/or luteal phase-deficient (n=4) and oral contraceptive pill users (n=10). Participants completed trials ~2 weeks apart in their (quasi-) early follicular and mid-luteal phases in two of moderate (1.3±0.1 kPa, 20.5±0.5 °C, 18 trials), warm-dry (2.2±0.2 kPa, 34.1±0.2 °C, 46 trials) or warm-humid (3.4±0.1 kPa, 30.2±1.1 °C, 66 trials) environments. We quantified reliability using limits of agreement, intraclass correlation coefficient (ICC), Pearson's correlation coefficient (r), standard error of measurement (SEM) and coefficient of variation (CV). Test-retest reliability was high, clinically-valid (ICC=0.90, r=0.83, both p<0.01) and acceptable with a mean CV of 4.7%, SEM of 3.8 kJ (2.1 W) and reliable bias of -2.1 kJ (-1.2 W). The various ovulatory status and contrasting ambient conditions had no appreciable effect on reliability. These results indicate that athletic women can perform 30-min self-paced work trials ~2 weeks apart with an acceptable and low variability irrespective of their hormonal status or heat-stressful environments.

scholarly journals Validity, Reliability and Reproducibility of Space Analysis using Digital Model taken via Model Scanner and Intraoral Scanner: An In vivo Study

2020 ◽  
Vol 47 (2) ◽  
pp. 176-187
Author(s):  
Seohyun Park ◽  
Jongsoo Kim ◽  
Sohee Oh
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation ◽  
Digital Model ◽  
Intraoral Scanner ◽  
3 Dimensional ◽  
Space Analysis ◽  
Tooth Width ◽  
Significant Difference ◽  
Plaster Model

The purpose of this study is to evaluate validity, reliability and reproducibility of tooth width (TW), arch length (AL) and arch length discrepancy (ALD) measured on a digital model taken via 3-dimensional model scanner and intraoral scanner compared to a plaster model.<br/>A total of 30 patients aged 12 to 18 were eligible for the study. 3 types of models were acquired from each patient: a conventional plaster model (P), a model scanned digital model (MSD) taken via Freedom UHD<sup>®</sup> and an intraoral scanned digital model (ISD) taken via CS3600<sup>®</sup> in-vivo. The reliability of TW and AL in each group was evaluated using Pearson’s correlation coefficient, while the reproducibility was evaluated with intraclass correlation coefficient. The validity of space analysis was assessed by paired t-test.<br/>As a result, all measurements of P, MSD and ISD groups showed favorable reliability and reproducibility. Most of measurements for space analysis in MSD group and TW in ISD group also presented high validity. AL and ALD presented statistically significant difference between P and ISD group. The validity of measurements of space analysis in ISD group was short in doubt to valid, but clinically acceptable. Both MSD and ISD are clinically acceptable to use for space analysis but clinician should be aware that errors can be found using a digital model.

scholarly journals Precision of the virtual occlusal record

2019 ◽  
Vol 89 (5) ◽  
pp. 751-757 ◽  
Author(s):  
Keyan P. Botsford ◽  
Michael C. Frazier ◽  
Ahmed A. M. Ghoneima ◽  
Achint Utreja ◽  
Surya S. Bhamidipalli ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Statistical Significance ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Normal Pressure ◽  
Software Systems ◽  
Kappa Statistics ◽  
Intraoral Scanner ◽  
Significant Difference

ABSTRACT Objectives: To evaluate the precision of the virtual occlusal record using the Carestream CS3600 Intraoral Scanner (Carestream Dental, Atlanta, Ga). Materials and Methods: A total of 20 participants were recruited for this prospective study using preestablished inclusion/exclusion criteria. A complete intraoral scan and two bite registrations were obtained. The participants were instructed to bite with normal pressure when bite registrations were acquired. Contact locations, size (circumference), and intensity were identified on the maxillary first molars and canines. Agreement between contact size and intensity was assessed with intraclass correlation coefficients. Kappa statistics evaluated agreement in contact locations. Statistical significance was set at P &lt; .05. Results: All participant data were included for statistical analysis. Between the two bite registrations, nonstatistically significant differences were observed in the proportion of locations with contacts (P = .7681). A nonstatistically significant difference (−0.25 mm, P = .8416) in mean contact circumference size was observed. A statistically significant difference in mean contact intensity was observed (P = .0448). When evaluating agreement between the bite registrations, a weak correlation for size (intraclass correlation coefficient = 0.35) and intensity (intraclass correlation coefficient = 0.32) was observed as well as a moderate agreement for contact location (κ coefficient = 0.67). Conclusions: The findings suggest that the Carestream intraoral scanner software possesses adequate precision when acquiring the location and size of the contacts in bite registrations. The scanner failed to demonstrate adequate precision when acquiring contact intensities in bite registrations. Additional research is warranted to further investigate the precision of virtual occlusal records with currently available software systems.

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