scholarly journals Application of 3D-printed plastic teeth in the teaching of tooth morphology

2020 ◽  
Author(s):  
Helin Wang ◽  
Haokun Xu ◽  
Junhua Zhang ◽  
Shibin Yu ◽  
Meiqing Wang ◽  
...  
Keyword(s):  
Morphological Characteristics ◽  
Two Dimensional ◽  
Tooth Morphology ◽  
Plastic Model ◽  
Tooth Structure ◽  
Anonymous Questionnaire ◽  
Significant Difference ◽  
Morphology And Structure ◽  
3D Printed ◽  
Medical University

Abstract Background: The "tooth morphology" course is an important basic stomatology course. But it is difficult to fully reflect the 3D morphological characteristics of tooth structure in the two-dimensional pictures in traditional textbooks. The aim of this study was to assess the effect of 3D-printed plastic model teeth in the teaching of tooth morphology. Methods: Forty-five undergraduate stomatology students who had matriculated at the Fourth Medical University in 2014 and 23 who had matriculated in 2016 were involved in the study. Each student who matriculated in 2016 was given a full set of 14 standard 3D-printed plastic model teeth for use during the learning process, and an anonymous questionnaire was used to evaluate the 3D-printed plastic model teeth from the perspective of the students. Results: There was no significant difference in the scores of the theoretical examination and the total score between the two groups. However, for the score of the sculpted gypsum teeth, students who used the 3D-printed plastic model teeth in their studies scored significantly higher (P=0.002). More than 90% of the students thought that the 3D-printed plastic model teeth were of great help or were very helpful for mastering the anatomy of teeth and for carving the plaster teeth.Conclusion: The standard 3D-printed plastic teeth can effectively assist students in learning tooth morphology by transforming the two-dimensional pictures and descriptions in the textbook into a 3D conformation, effectively promoting students' learning and mastery of tooth morphology and structure. Additionally, the results suggest that the 3D-printed plastic teeth are of great help to the students in mastering and improving their carving skills.

scholarly journals The effect of 3D-printed plastic teeth on scores in a tooth morphology course in a Chinese university

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Helin Wang ◽  
Haokun Xu ◽  
Junhua Zhang ◽  
Shibin Yu ◽  
Meiqing Wang ◽  
...  
Keyword(s):  
Undergraduate Students ◽  
Three Dimensional ◽  
Morphological Characteristics ◽  
Two Dimensional ◽  
Tooth Morphology ◽  
Plastic Model ◽  
Tooth Structure ◽  
Significant Difference ◽  
3D Printed ◽  
Medical University

Abstract Background The tooth morphology course is an important basic dental course. However, it is difficult to fully reflect the three-dimensional (3D) morphological characteristics of tooth structure in two-dimensional pictures in traditional textbooks. The aim of this study was to assess the effect of 3D-printed plastic model teeth in the teaching of tooth morphology. Methods Twenty-two undergraduate students who matriculated at the School of Stomatology, the Fourth Medical University, in 2014 and 23 who matriculated in 2016 participated in the study. Each student who matriculated in 2016 was given a full set of fourteen standard 3D-printed plastic model teeth for use during the learning process, and an anonymous questionnaire was used to evaluate the usefulness of the 3D-printed plastic model teeth from the perspective of the students. Results There was no significant difference between the two groups in the scores of the theoretical examination or the total score. However, for the score of the sculpted gypsum teeth, the students who used the 3D-printed plastic model teeth in their studies scored significantly higher (P = 0.002). More than 90% of the students thought that the 3D-printed plastic model teeth were of great help or were very helpful for mastering the anatomy of teeth and for carving the gypsum teeth. Conclusion Standard 3D-printed plastic teeth can effectively assist students in learning tooth morphology by transforming two-dimensional pictures and descriptions in the textbook into a 3D conformation, effectively promoting students’ learning and mastery of tooth morphology and structure. Additionally, the results suggest that 3D-printed plastic model teeth are of great help to the students in mastering and improving their carving skills.

scholarly journals The effect of 3D-printed plastic teeth on scores in a  tooth morphology course in a Chinese university

2020 ◽  
Author(s):  
Helin Wang ◽  
Haokun Xu ◽  
Junhua Zhang ◽  
Shibin Yu ◽  
Meiqing Wang ◽  
...  
Keyword(s):  
Undergraduate Students ◽  
Three Dimensional ◽  
Morphological Characteristics ◽  
Two Dimensional ◽  
Tooth Morphology ◽  
Plastic Model ◽  
Tooth Structure ◽  
Significant Difference ◽  
3D Printed ◽  
Medical University

Abstract Background: The tooth morphology course is an important basic dental course. However, it is difficult to fully reflect the three-dimensional (3D) morphological characteristics of tooth structure in two-dimensional pictures in traditional textbooks. The aim of this study was to assess the effect of 3D-printed plastic model teeth in the teaching of tooth morphology. Methods: Twenty-two undergraduate students who matriculated at the School of Stomatology, the Fourth Medical University, in 2014 and 23 who matriculated in 2016 participated in the study. Each student who matriculated in 2016 was given a full set of fourteen standard 3D-printed plastic model teeth for use during the learning process, and an anonymous questionnaire was used to evaluate the usefulness of the 3D-printed plastic model teeth from the perspective of the students. Results: There was no significant difference between the two groups in the scores of the theoretical examination or the total score. However, for the score of the sculpted gypsum teeth, the students who used the 3D-printed plastic model teeth in their studies scored significantly higher (P=0.002). More than 90% of the students thought that the 3D-printed plastic model teeth were of great help or were very helpful for mastering the anatomy of teeth and for carving the gypsum teeth. Conclusion: Standard 3D-printed plastic teeth can effectively assist students in learning tooth morphology by transforming two-dimensional pictures and descriptions in the textbook into a 3D conformation, effectively promoting students' learning and mastery of tooth morphology and structure. Additionally, the results suggest that 3D-printed plastic model teeth are of great help to the students in mastering and improving their carving skills.

F.VIII R:Ag in Hepatitis

1979 ◽  
Author(s):  
R. Kotitschke ◽  
J. Scharrer
Keyword(s):  
Chronic Hepatitis ◽  
Blood Donors ◽  
Blood Donation ◽  
Normal Population ◽  
Rabbit Antiserum ◽  
Two Dimensional ◽  
Plastic Plate ◽  
Significant Difference ◽  
Acute Hepatitis B ◽  
The One

F.VIII R:Ag was determined by quantitative immunelectrophoresis (I.E.) with a prefabricated system. The prefabricated system consists of a monospecific f.VIII rabbit antiserum in agarose on a plastic plate for the one and two dimensional immunelectrophoresis. The lognormal distribution of the f.VIII R:Ag concentration in the normal population was confirmed (for n=70 the f.VIII R:Ag in % of normal is = 95.4 ± 31.9). Among the normal population there was no significant difference between blood donors (one blood donation in 8 weeks; for n=43 the f.VIII R:Ag in % of normal is = 95.9 ± 34.0) and non blood donors (n=27;f.VIII R:Ag = 94.6 ± 28.4 %). The f.VIII R:Ag concentration in acute hepatitis B ranged from normal to raised values (for n=10, a factor of 1.8 times of normal was found) and was normal again after health recovery (n=10, the factor was 1.0). in chronic hepatitis the f.VIII R:Ag concentration was raised in the majority of the cases (for n=10, the factor was 3.8). Out of 22 carrier sera 20 showed reduced, 2 elevated levels of the f.VIII R:Ag concentration. in 5 sera no f.VIII R:Ag could be demonstrated. The f.VIII R:Ag concentration was normal for n=10, reduced for n=20 and elevated for n=6 in non A-non B hepatitis (n=36). Contrary to results found in the literature no difference in the electrophoretic mobility of the f.VIII R:Ag was found between hepatitis patients sera and normal sera.

Two Adhesive Systems-effect on Adhesion to Tooth Structure

2019 ◽  
Vol 70 (7) ◽  
pp. 2608-2613
Author(s):  
Larisa Simona Deac ◽  
Kamel Earar ◽  
Adela Loredana Colceriu Burtea ◽  
Alexandra Stefania Berghe ◽  
Aurora Antoniac ◽  
...  
Keyword(s):  
Adhesive Systems ◽  
Hybrid Layer ◽  
Tooth Structure ◽  
Selective Etch ◽  
Etch And Rinse ◽  
Significant Difference ◽  
Wisdom Teeth ◽  
Group 2 ◽  
Self Etch ◽  
Group 1

This study evaluates and compares by dye penetration method and SEM photomicrographs the sealing obtained using two different classes of adhesive systems (etch-and-rinse and self-etch with selective etching) with SDR (Dentsply) bulk fill composite. 84 class V cavities were prepared on oral and vestibular face of 42 intact, freshly extracted wisdom teeth. The cavities were randomly divided in two groups and restored: Group 1 with prime &bond one select (Dentsply) and SDR (Dentsply) and Group 2 with prime&bond one Etch&Rinse (Dentsply) and SDR (Dentsply). Prime&bond one Select (Dentsply) is a single component adhesive and can be used in self etch mode, in selective enamel etch mode, or in etch-and-rinse mode. We chosen for this study the selective etch of the enamel mode. Prime&bond one Etch Rinse (Dentsply) is a universal etch-and-rinse one-bottle dental adhesive, designed to be used in two steps. The bulk fill composites are commonly used in modern dentistry due to their properties of low polymerization shrinkage and curing in layer of 4 mm depth, offering the practitioner a fast clinical procedure with good results. The results showed a good sealing at enamel and dentin margins with no statistically significant difference between adhesives, even though the mean of enamel infiltration was smaller for Group1. Furthermore the results show that there were differences between the two groups, for the infiltrations at the enamel, the values of microleakage being arithmetically higher for Group 1, but with no statistically difference between the two groups.SEM images showed for both groups a good adhesion surface with the tooth, but the hybrid layer of the total-etch adhesives is different from the hybrid layer formed by self etch adhesives, in terms of thickness, uniformity. In conclusion both adhesive systems have equivalent sealing qualities and can be successfully used with SDR.

scholarly journals Dimensional Accuracy of Dental Models for Three-Unit Prostheses Fabricated by Various 3D Printing Technologies

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1550
Author(s):  
Soo-Yeon Yoo ◽  
Seong-Kyun Kim ◽  
Seong-Joo Heo ◽  
Jai-Young Koak ◽  
Joung-Gyu Kim
Keyword(s):  
Surface Roughness ◽  
Three Dimensional ◽  
Dimensional Accuracy ◽  
3D Analysis ◽  
Digital Light Processing ◽  
Test Models ◽  
Reference File ◽  
Significant Difference ◽  
Jet Printing ◽  
3D Printed

Previous studies on accuracy of three-dimensional (3D) printed model focused on full arch measurements at few points. The aim of this study was to examine the dimensional accuracy of 3D-printed models which were teeth-prepped for three-unit fixed prostheses, especially at margin and proximal contact areas. The prepped dental model was scanned with a desktop scanner. Using this reference file, test models were fabricated by digital light processing (DLP), Multi-Jet printing (MJP), and stereo-lithography apparatus (SLA) techniques. We calculated the accuracy (trueness and precision) of 3D-printed models on 3D planes, and deviations of each measured points at buccolingual and mesiodistal planes. We also analyzed the surface roughness of resin printed models. For overall 3D analysis, MJP showed significantly higher accuracy (trueness) than DLP and SLA techniques; however, there was not any statistically significant difference on precision. For deviations on margins of molar tooth and distance to proximal contact, MJP showed significantly accurate results; however, for a premolar tooth, there was no significant difference between the groups. 3D color maps of printed models showed contraction buccolingually, and surface roughness of the models fabricated by MJP technique was observed as the lowest. The accuracy of the 3D-printed resin models by DLP, MJP, and SLA techniques showed a clinically acceptable range to use as a working model for manufacturing dental prostheses

Poro-Elasto-Plastic Model for Wave-Induced Liquefaction

2014 ◽  
Author(s):  
Chengcong Liao ◽  
Hongyi Zhao ◽  
Dong-Sheng Jeng
Keyword(s):  
Two Dimensional ◽  
Plastic Model ◽  
Centrifuge Tests ◽  
Pore Pressures ◽  
Proposed Model ◽  
Progressive Waves ◽  
Plastic Components ◽  
Excess Pore Pressures ◽  
Wave Induced ◽  
Pore Pressure Build Up

In this study, a two-dimensional poro-elasto-plastic model for the wave-induced liquefaction in a porous seabed was presented. Two mechanisms of the wave-induced pore pressures were considered. Both elastic components (for oscillatory) and the plastic components (for residual) were integrated to predict the wave-induced excess pore pressures in marine sediments. The proposed 2D poro-elasto-plastic model allows for the pore pressure build-up process in a sandy seabed. The proposed model overall agreed well with the previous wave experiments and centrifuge tests. Numerical example shows that the pattern of progressive waves -induced liquefaction gradually changed from 2D to 1D.

scholarly journals Volume Measurements in Aortic Root Assessment Using Two-Dimensional Echocardiography

2016 ◽  
Vol 10 ◽  
pp. CMC.S39383
Author(s):  
Adebayo T. Oyedeji ◽  
Bolaji E. Egbewale ◽  
Adeseye A. Akintunde ◽  
Ebenezer A. Ajayi ◽  
Olukolade O. Owojori ◽  
...  
Keyword(s):  
Aortic Root ◽  
Normal Population ◽  
Age Groups ◽  
Aortic Dilatation ◽  
Two Dimensional ◽  
Linear Measurements ◽  
2D Echocardiography ◽  
Significant Difference ◽  
Volume Measurements ◽  
Dimensional Echocardiography

Background Aortic dilatation is associated with the presence of aortic diseases. Current guidelines for assessing the aortic root (AoR) depend on linear measurements acquired by two-dimensional (2D) echocardiography. We considered that real-time three-dimensional echocardiography, which correlates better with AoR volume obtained by computed tomography, is widely unavailable, and therefore, there is a need to determine the AoR volume using 2D echocardiography. Methods Fifty-one consecutive apparently healthy volunteers were recruited and subsequently divided into three age groups. Specified planes of acquisition and previously defined landmarks were identified, and phases of the cardiac cycle that allowed for measurement standardization were used. Volume was determined by the modified Simpson's method. Results Although the average diastolic and systolic volume measurements of the AoR dimensions were not significantly different across the three age groups in the study population, a highly significant difference was observed in the volume measurements between male and female normotensive persons, P < 0.01 in each case. AoR volume measurements were five times in the diseased compared with the normotensive individuals; however, linear measurements were only 1.5 times in size of the normal individuals. Both point and interval estimates of the volume measurements of AoR in adult normotensives in three age groups were presented as baseline information. Conclusions We hereby present a novel way to determine the AoR volume using 2D echocardiography and the normal reference range with respect to age and gender. We also established the relevance of our measurement by comparing the normal population with two isolated diseased aortas.

scholarly journals Characterizing sand ripples at equilibrium phases

2013 ◽  
Vol 61 (4) ◽  
pp. 293-298 ◽  
Author(s):  
Jie Qin ◽  
Deyu Zhong ◽  
Guangqian Wang
Keyword(s):  
Time Series ◽  
Random Fields ◽  
Morphological Characteristics ◽  
Structure Functions ◽  
Second Order ◽  
Order Structure ◽  
Two Dimensional ◽  
Sand Ripples ◽  
Digital Elevation ◽  
Equilibrium Phases

Abstract Morphological characteristics of ripples are analyzed considering bed surfaces as two dimensional random fields of bed elevations. Two equilibrium phases are analyzed with respect to successive development of ripples based on digital elevation models. The key findings relate to the shape of the two dimensional second-order structure functions and multiscaling behavior revealed by higher-order structure functions. Our results suggest that (1) the two dimensional second-order structure functions can be used to differentiate the two equilibrium phases of ripples; and (2) in contrast to the elevational time series of ripples that exhibit significant multiscaling behavior, the DEMs of ripples at both equilibrium phases do not exhibit multiscaling behavior.

scholarly journals What is the knowledge of tubercular patients about risk factors contributing to development of their disease

2006 ◽  
Vol 134 (Suppl. 2) ◽  
pp. 122-127 ◽  
Author(s):  
Miroslav Ilic
Keyword(s):  
Diabetes Mellitus ◽  
Risk Factors ◽  
Main Risk Factor ◽  
Active Pulmonary Tuberculosis ◽  
Anonymous Questionnaire ◽  
Number Of Patients ◽  
Significant Difference ◽  
Level Of Knowledge ◽  
Basic Characteristics

INTRODUCTION. Present knowledge of population on basic characteristics of tuberculosis is a significant issue of prevention of tuberculosis. OBJECTIVE. The objective of our study was to determine the level of knowledge on risk factors of tuberculosis among tubercular patients. METHOD. A total of 115 new patients with the active pulmonary tuberculosis were interviewed by means of anonymous questionnaire, who has been treated at the Institute of Pulmonary Diseases, Sremska Kamenica during six-month period (October 2003-March 2004). RESULTS. The patients fulfilled the questionnaire; 37.6 % had no or finished only elementary school, and 58.6 % considered genetics the main risk factor of tuberculosis. Every second patient believed that he could not catch tuberculosis if he suffered from diabetes mellitus or any kind of tumor. 8.7 % of patients who suffered from diabetes mellitus had been informed by their physicians that could catch tuberculosis one day. Every third patient did not possess sewage system and nearly 20% lived in moist flats. Around 85% had no regular salaries or these were significantly under the average Serbian income per capita in this period (12820 dinars-CSD). Leading risk factors that can contribute to development of tuberculosis were as follows: irregular nutrition (91.4 %), smoking (74.2 %), alcohol consumption (65.5%) and associated diseases (diabetes mellitus, tumors). Only 15% of them believed that all these risk factors (smoking, alcohol, irregular diet) could participate together in development of tuberculosis, and not as individual factors. Analyzing the patients? knowledge on risk factors of tuberculosis, in relation to their educational level and alcohol and cigarettes consumption, there was no significant difference (p<0.05). Nevertheless, analyzing the quality of life in patients? houses, in relation to salary and bad habits (alcohol, cigarettes) as risk factors of tuberculosis, significant statistical difference was found (p>0.05). CONCLUSION. Intensive and permanent education of population is necessary primarily considering the knowledge on tuberculosis that would be the basis of reducing the number of patients and leading to possible eradication of this disease.

scholarly journals PERBEDAAN LEBAR CELAH TEPI TUMPATAN SEMEN IONOMER KACA MODIFIKASI RESIN NANO DAN MODIFIKASI RESIN

2017 ◽  
Vol 4 (1) ◽  
pp. 7
Author(s):  
Yuliana Ratna Kumala ◽  
Dini Rachmawati ◽  
Amanda Andika Sari
Keyword(s):  
Artificial Saliva ◽  
Statistical Test ◽  
Nano Particles ◽  
Marginal Gap ◽  
Nano Technology ◽  
Tooth Structure ◽  
Significant Difference ◽  
Conventional Material ◽  
Gap Width ◽  
Ionomer Cement

Background: One over many ways to treat dental caries is by restoration.Glass ionomer cement (GIC) is the restorations material that bonds physically and chemically to tooth structure. GIC has been developed by combining the conventional material with monomer resin, known as resin  modified GIC (RMGIC). Presently, with the development of nano  technology, RMGIC restoration also available in the form of nano   particles, called nanofilled RMGIC (RMGICn). One disadvantage of GIC is the marginal gap which may affects the durability ofrestoration. Purpose: The purpose of this study to compare the marginal gap width of RMGIC and nanofilled RMGIC.Methods: This study used scanning electron microscope (SEM) to observing and measuring the marginal gap width in two kelompoks of 9 maxillary first premolar teeth. The first kelompok restored with RMGIC, the second kelompok restored with nanofilled RMGIC. Following immersion in artificial saliva and the teeth were thermocycled at a temperature of 5oC, 37oC, and 55oC (250 cycles) 1 minute each. Data analysis was done using independent t-test with 95% confidence interval (α = 0.05).Results: Statistical test showed a significant difference for marginal gap width in both kelompok (p = 0.000).Conclusion: There is marginal gap in RMGIC and RMGICn restoration. RMGIC restoration presented lower marginal gap width than RMGIC.

Sign in / Sign up

Export Citation Format

Share Document