scholarly journals Assessment of the reproducibility and precision of milling and 3D printing surgical guides

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sueli Mukai ◽  
Eduardo Mukai ◽  
José Arnaldo Santos-Junior ◽  
Jamil Awad Shibli ◽  
Marcelo Faveri ◽  
...  
Keyword(s):  
3D Printing ◽  
Virtual Model ◽  
Virtual Design ◽  
Surgical Guides ◽  
Technology Advancement ◽  
Significant Difference ◽  
Kolmogorov Smirnov ◽  
3D Printed ◽  
Test For Normality ◽  
Smirnov Test

Abstract Background Technology advancement has rising in the past decade and brought several innovations and improvements. In dentistry, this advances provided more comfortable and quick procedures to both the patient and the dental surgeon, generating less predictability in the final result. Several techniques has been developed for the preparation of surgical guides aiming at the optimization of surgical procedures. The present study aimed to evaluate the reproducibility and precision of two types of surgical guides obtained using 3D printing and milling methods. Methods A virtual model was developed that allowed the virtual design of milled (n = 10) or 3D printed (n = 10) surgical guides. The surgical guides were digitally oriented and overlapped on the virtual model. For the milling guides, the Sirona Dentsply system was used, while the 3D printing guides were produced using EnvisionTEC’s Perfactory P4K Life Series 3D printer and E-Guide Tint, a biocompatible Class I certified material. The precision and trueness of each group during overlap were assessed. The data were analyzed with GraphPad software using the Kolmogorov–Smirnov test for normality and Student’s t test for the variables. Results The Kolmogorov–Smirnov test showed a normal distribution of the data. Comparisons between groups showed no statistically significant differences for trueness (p = 0.529) or precision (p = 0.3021). However, a significant difference was observed in the standard deviation of mismatches regarding accuracy from the master model (p < 0.0001). Conclusions Within the limits of this study, surgical guides fabricated by milling or prototyped processes achieved similar results.

scholarly journals Assessment Of The Reproducibility And Precision For Milling And 3d Printing Surgical Guides

2019 ◽  
Author(s):  
Sueli Mukai ◽  
Eduardo Mukai ◽  
Jamil Awad Shibli DDS ◽  
GABRIELA GIRO
Keyword(s):  
3D Printing ◽  
Coefficient Of Variation ◽  
Virtual Model ◽  
Mean Square ◽  
Virtual Design ◽  
Surgical Guide ◽  
Surgical Guides ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
Master Model

Abstract Objective: The aim of the present study was to evaluate the reproducibility and precision of two types of surgical guides, obtained by using 3D printing and milling methods. Methods: A virtual model was developed, which allowed the virtual design of surgical guide project that were milled (n = 10) or 3D printing (n = 10). Surgical guides were digitally oriented and overlapped on the virtual model that had generated them. For milling guides, it was used the Sirona Dentsply system, while 3D printing guides were produced at the Perfactory P4K Life Series, the EnvisionTEC's E-Guide Tint. In this way, average mismatches from the master model were determined. Moreover, coefficients of variation, root mean square deviations, and mismatches during an overlap were evaluated after obtaining individual misalignments for each guide, in order to verify the reproducibility of the guides and the precision of the methods for obtaining the guides Results: The evaluations showed that both groups presented the same degree of mismatch during overlap, with no statistically significant differences between the groups. However, the intragroup evaluation for misalignment, 3D printing surgical guides had a higher coefficient of variation than the milled guides, since a statistically significant difference was observed between groups in the RMS of the guide from the master model. Conclusions: Milling of the guides resulted in smaller misalignments from the master model.

Investigation of The Nutritional Approaches of Student Athletes During The Covid-19 Epidemic

2021 ◽  
Vol 15 (7) ◽  
pp. 1940-1944
Author(s):  
Sevcan Altun ◽  
Aykut Aksu ◽  
Osman Imamoglu ◽  
Murat Erdogdu ◽  
Kursat Karacabey
Keyword(s):  
Student Athletes ◽  
Eating Habits ◽  
T Test ◽  
Outbreak Period ◽  
Significant Difference ◽  
Package Program ◽  
Kolmogorov Smirnov ◽  
The Subject ◽  
The University ◽  
Smirnov Test

The aim of this study is to investigate the nutritional approaches of student athletes studying at the university during the coronavirus outbreak period. Participants consisted of students studying and doing sports at the University. 446 students, 246 males and 200 females, participated in the study. Besides the personal form, students were filled the questionnaire testing questionnaire. Students voluntarily participated. The surveys were done on social media. Nutritional habits questionnaire consists of 12 questions. In the preparation of the survey questions, the questions proved validity of the researches which have been done on the subject before have been used. SPSS 23.00 package program was used in statistical analyses. Kolmogorov-Smirnov test was performed to test whether the data was normally distributed and it was determined that the data showed normal distribution. Independent t-test, paired t-test, unidirectional variance analysis and LSD tests were used in statistical operations. There was no significant difference in students' nutrition approaches by gender, both in the pre-outbreak period and in the outbreak period points (p> 0.05). Nutrition scores were significantly increased during the outbreak period (p <0.001). A significant difference was found between the students who felt bad before the epidemic and those who felt well before the epidemic and their nutritional scores according to the levels they felt (p <0.05). A significant difference was found between the pre-outbreak period and post-epidemic nutrition scores of the sports faculty students (p <0.05). During the coronavirus epidemic, university student athletes have either increased their nutritional opportunities or have changed their eating habits positively to keep their immune systems strong or both. The fact that sports faculty students have better nutrition compared to other faculty students can be attributed to their taking courses in nutrition, health and similar. It is recommended to give lectures or seminars on nutrition to athlete students. Keywords: Student, Nutrition, Sports Nutrition, Nutritional Approach, Covid-19

Investigation of three-dimensional printing materials for printing aorta model replicating Type B aortic dissection

2021 ◽  
Vol 17 ◽  
Author(s):  
Chia-An Wu ◽  
Andrew Squelch ◽  
Zhonghua Sun
Keyword(s):  
3D Printing ◽  
Aortic Dissection ◽  
Three Dimensional ◽  
Ct Images ◽  
Patient Specific ◽  
Type B ◽  
Type B Aortic Dissection ◽  
Ct Attenuation ◽  
Significant Difference ◽  
3D Printed

Aim: To determine a printing material that has both elastic property and radiology equivalence close to real aorta for simulation of endovascular stent graft repair of aortic dissection. Background: With the rapid development of three-dimensional (3D) printing technology, a patient-specific 3D printed model is able to help surgeons to make better treatment plan for Type B aortic dissection patients. However, the radiological properties of most 3D printing materials have not been well characterized. This study aims to investigate the appropriate materials for printing human aorta with mechanical and radiological properties similar to the real aortic computed tomography (CT) attenuation. Objective: Quantitative assessment of CT attenuation of different materials used in 3D printed models of aortic dissection for developing patient-specific 3D printed aorta models to simulate type B aortic dissection. Method: A 25-mm length of aorta model was segmented from a patient’s image dataset with diagnosis of type B aortic dissection. Four different elastic commercial 3D printing materials, namely Agilus A40 and A50, Visijet CE-NT A30 and A70 were selected and printed with different hardness. Totally four models were printed out and conducted CT scanned twice on a 192-slice CT scanner using the standard aortic CT angiography protocol, with and without contrast inside the lumen.Five reference points with region of interest (ROI) of 1.77 mm2 were selected at the aortic wall and intimal flap and their Hounsfield units (HU) were measured and compared with the CT attenuation of original CT images. The comparison between the patient’s aorta and models was performed through a paired-sample t-test to determine if there is any significant difference. Result: The mean CT attenuation of aortic wall of the original CT images was 80.7 HU. Analysis of images without using contrast medium showed that the material of Agilus A50 produced the mean CT attenuation of 82.6 HU, which is similar to that of original CT images. The CT attenuation measured at images acquired with other three materials was significantly lower than that of original images (p<0.05). After adding contrast medium, Visijet CE-NT A30 had an average CT attenuation of 90.6 HU, which is close to that of the original images with statistically significant difference (p>0.05). In contrast, the CT attenuation measured at images acquired with other three materials (Agilus A40, A50 and Visiject CE-NT A70) was 129 HU, 135 HU and 129.6 HU, respectively, which is significantly higher than that of original CT images (p<0.05). Conclusion: Both Visijet CE-NT and Agilus have tensile strength and elongation close to real patient’s tissue properties producing similar CT attenuation. Visijet CE-NT A30 is considered the appropriate material for printing aorta to simulate contrast-enhanced CT imaging of type B aortic dissection. Due to lack of body phantom in the experiments, further research with simulation of realistic anatomical body environment should be conducted.

scholarly journals Development of Soft sEMG Sensing Structures Using 3D-Printing Technologies

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4292
Author(s):  
Gerjan Wolterink ◽  
Pedro Dias ◽  
Remco G. P. Sanders ◽  
Frodo Muijzer ◽  
Bert-Jan van Beijnum ◽  
...  
Keyword(s):  
3D Printing ◽  
Biceps Brachii ◽  
Low Cost ◽  
Recognition Algorithm ◽  
Practical Applications ◽  
Variable Level ◽  
Processing Step ◽  
Significant Difference ◽  
3D Printed ◽  
Emg Electrodes

3D printing of soft EMG sensing structures enables the creation of personalized sensing structures that can be potentially integrated in prosthetic, assistive and other devices. We developed and characterized flexible carbon-black doped TPU-based sEMG sensing structures. The structures are directly 3D-printed without the need for an additional post-processing step using a low-cost, consumer grade multi-material FDM printer. A comparison between the gold standard Ag/AgCl gel electrodes and the 3D-printed EMG electrodes with a comparable contact area shows that there is no significant difference in the EMG signals’ amplitude. The sensors are capable of distinguishing a variable level of muscle activity of the biceps brachii. Furthermore, as a proof of principle, sEMG data of a 3D-printed 8-electrode band are analyzed using a patten recognition algorithm to recognize hand gestures. This work shows that 3D-printed sEMG electrodes have great potential in practical applications.

Utility and cost–effectiveness of 3D-printed materials for clinical use

2019 ◽  
Vol 3 (4) ◽  
pp. 209-218 ◽  
Author(s):  
Julian Vitali ◽  
Matthew Cheng ◽  
Michael Wagels
Keyword(s):  
Cost Effectiveness ◽  
3D Printing ◽  
Relevant Literature ◽  
Clinical Use ◽  
Surgical Guides ◽  
Rigorous Testing ◽  
Clinical Benefits ◽  
3D Printed ◽  
Surgical Adjunct ◽  
Printed Materials

This review summarizes the utility of 3D-printing as a surgical adjunct, reviewing the cost–effectiveness. The relevant literature was analyzed outlining the utility and/or cost–effectiveness of 3D-printing for clinical use. Compared with existing methods, the evidence suggests an advantage of using 3D-printing as a technology in the treatment of complex clinical cases. However, in high frequency cases, the additional preoperative expenses are not justified. Considerable evidence of its clinical benefits exists for the application of 3D-printed anatomical models and teaching tools. However, the evidence supporting 3D-printing’s use as surgical guides or implantable devices is less clear. Furthermore, caution must exist when using these devices in the clinical setting due to a paucity of rigorous testing, global regulation and long-term data.

scholarly journals A Cautionary Note on the Use of the Kolmogorov–Smirnov Test for Normality

2007 ◽  
Vol 135 (3) ◽  
pp. 1151-1157 ◽  
Author(s):  
Dag J. Steinskog ◽  
Dag B. Tjøstheim ◽  
Nils G. Kvamstø
Keyword(s):  
Goodness Of Fit ◽  
Small Sample ◽  
Power Comparison ◽  
Goodness Of Fit Test ◽  
Kolmogorov Smirnov ◽  
The Mean ◽  
Small Sample Problem ◽  
Tests For Normality ◽  
Test For Normality ◽  
Smirnov Test

Abstract The Kolmogorov–Smirnov goodness-of-fit test is used in many applications for testing normality in climate research. This note shows that the test usually leads to systematic and drastic errors. When the mean and the standard deviation are estimated, it is much too conservative in the sense that its p values are strongly biased upward. One may think that this is a small sample problem, but it is not. There is a correction of the Kolmogorov–Smirnov test by Lilliefors, which is in fact sometimes confused with the original Kolmogorov–Smirnov test. Both the Jarque–Bera and the Shapiro–Wilk tests for normality are good alternatives to the Kolmogorov–Smirnov test. A power comparison of eight different tests has been undertaken, favoring the Jarque–Bera and the Shapiro–Wilk tests. The Jarque–Bera and the Kolmogorov–Smirnov tests are also applied to a monthly mean dataset of geopotential height at 500 hPa. The two tests give very different results and illustrate the danger of using the Kolmogorov–Smirnov test.

Surgical Volume Affects Outcomes in Laryngectomy Procedures

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P84-84
Author(s):  
Brenda Mast ◽  
Guy J Petruzzelli ◽  
Tricia J Johnson
Keyword(s):  
Length Of Stay ◽  
Complication Rate ◽  
High Volume ◽  
Surgical Volume ◽  
Total Cost ◽  
Significant Difference ◽  
Dependent Variables ◽  
Kolmogorov Smirnov ◽  
The University ◽  
Smirnov Test

Objective To determine whether statistical differences occur in total cost, length of stay, ICU days, and surgical complications, depending on the volume of laryngectomy procedures performed. Methods Secondary laryngectomy data from 108 hospitals participating in the University Health System Consortium was examined. All laryngectomy surgical cases occurring from July 1, 2001, through June 30, 2005, with an ICD-9 code of 30.3 or 30.4 were analyzed (N=4,551). The cases were divided into 3 categories based on the number of surgical laryngectomy cases performed by hospital. Those volume categories were high, as defined by organizations with 100–233 cases (n=1712); medium, between 60–99 cases (n=1353); and low, between 4–59 cases (n=1458). 4 dependent variables were examined including total cost, length of stay, ICU days, and complications. Results The 4 dependent variables were analyzed for normality by performing a Kolmogorov-Smirnov test. All 4 variables were non-normally distributed. A Kruskal-Wallis test was then performed on each variable to determine if a statistically significant difference appeared between the 3 volume categories. Each variable was found to have statistical significant differences between the groups, with the high volume hospitals having the lowest cost, shortest length of stay, shortest ICU days, and smallest complication rate. Conclusions This study showed that hospitals with higher surgeon volume for total laryngectomies had reduced total cost, length of stay, number of ICU days, and complication rate for their patients.

scholarly journals Multi-Material 3D Printing of a Customized Sports Mouth Guard: Proof-of-Concept Clinical Case

2021 ◽  
Vol 18 (23) ◽  
pp. 12762
Author(s):  
Alexey Unkovskiy ◽  
Fabian Huettig ◽  
Pablo Kraemer-Fernandez ◽  
Sebastian Spintzyk
Keyword(s):  
3D Printing ◽  
Free Form ◽  
Proof Of Concept ◽  
Virtual Design ◽  
Digital Workflow ◽  
Protective Function ◽  
Drop On Demand ◽  
3D Printed ◽  
Mouth Guards ◽  
Protective Performance

A multilayer mouth guard is known to have the best protective performance. However, its manufacturing in a digital workflow may be challenging with regards to virtual design and materialization. The present case demonstrates a pathway to fabricate a multilayer individualized mouth guard in a fully digital workflow, which starts with intraoral scanning. A free-form CAD software was used for the virtual design. Two various CAM techniques were used, including Polyjet 3D printing of rubber-like soft material and silicone printing using Drop-on-Demand technique. For both methods the outer layer was manufactured from more rigid materials to facilitate its protective function; the inner layer was printed from a softer material to aid a better adaptation to mucosa and teeth. Both 3D printed multilayer mouth guards showed a clinically acceptable fit and were met with patient appraisal. Their protective capacities must be evaluated in further clinical studies.

scholarly journals Level of knowledge about handwashing and hand sanitizer at Taro village, Gianyar before and after counseling

2022 ◽  
Vol 13 (1) ◽  
pp. 250-254
Author(s):  
Maftuhatur Rizkiyah Putri ◽  
Almira Disya Salsabil ◽  
I Made Agus Dwipayana ◽  
Widati Fatmaningrum
Keyword(s):  
T Test ◽  
Paired Sample ◽  
Hand Sanitizer ◽  
Average Value ◽  
Normality Test ◽  
Significant Difference ◽  
Before And After ◽  
Kolmogorov Smirnov ◽  
Level Of Knowledge ◽  
Test For Normality

Introduction: The COVID-19 pandemic has harmed various fields, and people's activities cannot run as usual. Prevention of the transmission of COVID-19 is very important to be applied in everyday life. Washing hands with soap or hand sanitizer is easy and inexpensive prevention to do, but there are still many people who are wrong in practicing it. This needs to be done more counseling and education to the community in order to increase public knowledge about handwashing and hand sanitizer. Method: This research is an analytic study with a research design using a one-group pretest-posttest design. Using 31 respondents from Taro villagers who attended the counseling. Data analysis using Paired Sample T-test and Kolmogorov-Smirnov Test for Normality Test. Result: The average value of knowledge before counseling is 53.8710 while the value after counseling is 82.9677. Paired Sample T-test and obtained a significance value of 0.000 so that a significant difference was found (<0.005) between the values before and after counseling. Conclusion: There is a significant difference in the level of knowledge before and after handwashing and hand sanitizer counseling.

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