scholarly journals Effect of Veneering and Hydrothermal Aging on the Translucency of Newly Introduced Extra Translucent and High Translucent Zirconia with Different Thicknesses

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Sevki Cinar ◽  
Bike Altan
Keyword(s):  
Statistical Analysis ◽  
Contrast Ratio ◽  
Zirconia Ceramics ◽  
Hydrothermal Aging ◽  
Material Type ◽  
Significant Difference ◽  
Before And After ◽  
Cad Cam ◽  
Different Thickness

Purpose. The purpose of this study was to evaluate the effect of veneering and aging on the translucency of newly introduced extra and high translucent zirconia with different thickness. Materials and Methods. One hundred forty disk-shaped specimens were fabricated from two translucent zirconia blocks (VITA YZ XT and VITA YZ HT), and they are milled with CAD/CAM system. Then, specimens were divided into nonveneered (XT, HT) and veneered groups (XTV, HTV). Nonveneered groups were prepared with four different thicknesses (0.5-1-1.5-2 mm). Veneered groups were divided into three subgroups ( n = 10 ) for veneering with base dentin ceramic with thicknesses of 0.5 + 0.5 , 0.5 + 1 , and 0.5 + 1.5   mm . A spectrophotometer was used to calculate the translucency parameter (TP) and contrast ratio (CR) of all specimens before and after aging. Statistical analysis was performed using 3-way ANOVA and Tukey HSD tests ( p < 0.05 ). Results. TP values were significantly affected by thickness of specimens ( p < 0.001 ). VITA YZ XT was significantly found more translucent than VITA YZ HT. The highest translucency was observed in the XT-0.5 mm group. There is no significant difference between translucency of the veneered and nonveneered groups in the same thickness for XT. On the contrary, veneering significantly affected translucency of HT. TP values significantly decreased after aging for all groups. After aging, translucency value difference before and after aging was the highest in the XT-0.5 mm group whereas the HTV-2 mm group showed the lowest difference after aging. TP decreased significantly as thickness of specimen increases regardless of the material type. Extra translucent and nonveneered zirconia groups are more prone to hydrothermal aging. Conclusions. The translucency parameter of zirconia ceramics was significantly influenced by both material type and veneering. Also, extra translucent and nonveneered zirconia groups are more susceptible to hydrothermal aging.

Relative Translucency of IPS E.max LT Core Materials after Veneering and Glazing

2011 ◽  
Vol 492 ◽  
pp. 358-361 ◽  
Author(s):  
Ting Sun ◽  
Long Quan Shao ◽  
Jun Ai ◽  
Bin Deng ◽  
Ning Wen
Keyword(s):  
Contrast Ratio ◽  
White Background ◽  
Ceramic System ◽  
The Core ◽  
Significant Difference ◽  
All Ceramic ◽  
Before And After ◽  
Different Thickness ◽  
Core Materials

This study compared the translucency of IPS e.max all-ceramic system of A and D color series veneered and glazed at clinically appropriate thicknesses. Core specimens (n = 5) of IPS e.max were produced and veneered with IPS e.max veneering porcelain to final dimensions (13 mm in diameter, 0.6 mm in thickness for core specimens with a thickness of 0.3 and 1.0 mm for core specimens with a thickness of 0.5 mm). Luminous reflectance was measured three times each specimen with a calibrated spectrophotometer after veneering and again after glazing cycle. Contrast ratios (CR=Yb/Yw) were measured from the luminous reflectance (Y)of the tested specimens with a black (Yb) and a white background (Yw). There was no significant difference in contrast ratios of specimens within the same color series before and after glazing (P > 0.05). Significant difference was found in the contrast ratios of specimens of the same color but different thickness before and after glazing (P < 0.05). The specimens with a thickness of 1.0mm presents significantly higher contrast ratios than specimens of the same color with a thickness of 0.6mm before and after glazing. The contrast ratios of glazed specimens were significantly lower than nonglazed ones. The Contrast ratio increases as the thickness of the core veneer materials increase, while luminosity and chroma are not related to relative translucency. The glazing cycle results in decreased opacity for core veneer materials.

scholarly journals Surface Roughness and Translucency of Various Translucent Zirconia Ceramics after Hydrothermal Aging

2021 ◽  
Author(s):  
Chaimongkon Peampring ◽  
Santiphab Kengtanyakich
Keyword(s):  
Surface Roughness ◽  
Repeated Measures ◽  
Contrast Ratio ◽  
X Ray Diffraction ◽  
Hydrothermal Aging ◽  
Significant Difference ◽  
Before And After ◽  
Bonferroni Test ◽  
Group 2 ◽  
Group 1

Abstract Objective This study investigated the effect of hydrothermal aging on surface roughness and translucency of various translucent zirconia materials. Materials and Methods Four types of zirconia were tested. Group 1 was translucent zirconia with no cubic structure. Group 2, 3, and 4 included cubic-containing zirconia with different amounts of cubic structures (less than 30%, 30–50%, and more than 50%, respectively). Each group contained 15 disk-shape specimens with dimensions of 15 mm in diameter and 1 mm in thickness. As-sintered surface roughness, translucency parameter, and contrast ratio were evaluated in the two different sessions, before and after aging. Statistical Analysis Two-way repeated measures ANOVA with Bonferroni test was used to analyze statistically significant difference in those tested parameters. Phase structure before and after aging was analyzed by X-ray diffraction analysis (XRD). Results Groups 1 and 2 showed significant increased surface roughness after aging while groups 3 and 4 showed no alteration of surface. There was no effect of aging on translucency in all groups. After aging, group 1 and 2 presented monoclinic structure (16.63 and 5.01%, respectively). Conclusion Hydrothermal aging caused phase transformation and increasing surface roughness in group 1 and 2 but did not affect translucency in all groups.

scholarly journals Effect of Various Veneering Techniques on Bond Strength and Colour Stability of Zirconia / Veneering Ceramic after Hydrothermal Aging

2021 ◽  
Vol 10 (39) ◽  
pp. 3474-3479
Author(s):  
Rafat Sasany ◽  
Duygu Sarac ◽  
Goknil Ergun Kunt
Keyword(s):  
Bond Strength ◽  
In Vitro Study ◽  
Resin Cement ◽  
Colour Stability ◽  
Hydrothermal Aging ◽  
Significant Difference ◽  
Before And After ◽  
Cad Cam ◽  
Ceramic Restorations

BACKGROUND The purpose of this in-vitro study was to compare the colour stability and bond strength of zirconia-based ceramic restorations after hydrothermal aging using conventional layering, heat-pressing, and multilayer veneering techniques. METHODS One hundred twenty specimens’ core (15 x 10 x 0.7) was fabricated from A2-shade zirconia CAD-CAM blocks (IPS e.max ZirCAD). Specimens were divided into 4 groups for veneering (N = 30): [(layering group (L), IPS e.max ceram), (heat – pressing group (P), IPS press), and multilayer group, IPS e max Cad for 2 different types of cement (cemented with RelyX U200 (M1) and PANAVIA SA (M2))]. Aging was performed for (5 - 55°C, 5000). Colour coordinates before and after aging were measured to calculate colour differences (ΔE00). The shear bond strength test was performed with a universal test unit. The data were analysed using the analysis of variance (ANOVA) and Tukey’s Honest Significant Difference test (alpha = 0.05). RESULTS Significant differences were found between the groups in bond strength (P < 0.001). Group M1 had the highest bond strength while Group L had the lowest bond strength. In terms of ΔE00 values, there were significant variations between the groups (P < 0.001). Group M1 had the highest colour stability, while Group M2 had the lowest colour stability. CONCLUSIONS The method of fabrication had an impact on the power of the bond between veneering ceramic and zirconia, as well as its colour stability. The restoration fabricated by a multilayer technique was cemented by resin cement (Rely X U200 Automix) which was found to be more resistant and colour stable. KEY WORDS Veneers, Heat-Press Technique, Bond Strength, Colour Different, Hydrothermal Aging.

The Effect of Thickness on the Fracture Strength and Failure Modes of Zirconia Crowns

2016 ◽  
Vol 697 ◽  
pp. 629-632
Author(s):  
Li Xian Zhang ◽  
Rui Li ◽  
Yu Niu ◽  
Yu Xiao Liu
Keyword(s):  
Fracture Strength ◽  
Failure Modes ◽  
Statistical Significance ◽  
Dental Practice ◽  
Significant Difference ◽  
Cad Cam ◽  
Zirconia Crowns ◽  
Different Thickness

To explore the effect of thickness on the fracture strength and failure modes of zirconia crowns, four crown models with different thickness (1.2 mm, 1.0 mm, 0.8 mm, 0.6 mm) with the same shape were designed by Dental Designer software in CAD/CAM system. They were manufactured to 40 zirconia crowns by CAM carving machine. The fracture strength and the failure modes of each crown was measured, while porcelain fused to metal (PFM) crowns as control. The average fracture strength of different zirconia crowns were recorded as below: 1308.38 ± 111.38 N (Group 0.6 mm), 1841.60 ± 68.21 N (Group 0.8 mm), 2429.88 ± 315.03 N (Group 1.0 mm), 3068.31 ± 233.88 N (Group 1.2 mm). There was no significant difference between Group 1.0 mm and Group 1.2 mm (P > 0.05), and statistical significance was obtained among every other two groups (P < 0.05). The failure modes of different thickness zirconium crowns are similar. There are more broken pieces from thicker crowns compared to thinner ones. It is concluded that the thickness can influence the fracture strength of zirconia crown. With the increase of the thickness, the fracture strength of the zirconium crowns also increases. We recommend zirconia crowns thicker than or at least 1.0 mm in dental practice.

scholarly journals Statistical Analysis using traditional technique, Microsoft Excel and Predictive Analytic Software

10.17158/514 ◽  
2016 ◽  
Vol 19 (2) ◽  
Author(s):  
Jovelyn M. Durango ◽  
Carlito P. Yurango
Keyword(s):  
Statistical Analysis ◽  
Completion Time ◽  
Microsoft Excel ◽  
Instructional Tools ◽  
Traditional Technique ◽  
Significant Difference ◽  
Before And After ◽  
Computer Based ◽  
The One ◽  
Time Required

<p>The advent of technology has improved the way statistics is taught and learned. It is claimed that the use of computer-based instructional tools can actively explore the meaning of statistical concepts among the students, as well as enhance their learning experiences. This study aimed to compare three methods of statistical analysis namely, the traditional technique (use of the calculator), Microsoft Excel and Statistical Package for Social Sciences (SPSS) software. This investigation utilized the experimental design, specifically the One-Group Pretest – Posttest Design. There were six education students who self-assessed their attitude before and after the introduction of the use of various computation techniques and performed the statistical analysis considering also the completion time required for each process. Results of the study revealed an increase in the level of attitude among the respondents form the pretest to the posttest. Also, the cognitive level regardless of the approach was very high. However, the t-test failed to establish a significant difference in the attitude among the respondents. On the other hand, there were significant differences in both the test scores and completion time of the respondents in the three methods in favor of SPSS.</p><p> </p><p><strong>Keywords: </strong>Information technology, statistics, traditional technique, Microsoft excel, SPSS, comparative analysis, experimental research design, Davao City, Philippines. </p>

scholarly journals The Effects of the TPACK-P Educational Program on Teachers’ TPACK: Programming as a Technological Tool

2018 ◽  
Vol 7 (3.34) ◽  
pp. 636
Author(s):  
Seong Won Kim ◽  
Youngjun Lee
Keyword(s):  
Statistical Analysis ◽  
Training Program ◽  
Content Knowledge ◽  
Educational Program ◽  
Control Group ◽  
Significant Difference ◽  
Before And After ◽  
Post Test ◽  
Technological Tool ◽  
Experimental Group

Background/Objectives: This study examined the effects of introducing programming as a technological tool for teachers’ Technological Pedagogical Content Knowledge (TPACK) development.Methods/Statistical Analysis: Thirty-two teachers were divided into two groups, completing different types of TPACK educational programs. The control group’s TPACK training program was based on information and communication technology (ICT), while that of the experimental group was based on programming. To verify the effectiveness of the TPACK training program, tests were administered before and after the educational program. A statistical analysis of questionnaire results also investigated changes resulting from TPACK.Findings: Both the control and experimental groups showed statistically significant improvements in the post-test compared with the pre-test. However, in the detailed areas of TPACK by group, the improvements in the two groups differed. Unlike the control group, the experimental group showed a statistically significant improvement in the knowledge related to technology. This result illustrated that programming is effective in solving the problem of integrating technology into the classroom. In contrast, there was no significant difference in the post-test, as this was applied in the short term. However, programming has been shown to affect Technological Pedagogical Knowledge (TPK), Technological Content Knowledge (TCK), and TPACK. In summary, the results showed that a TPACK educational program based on programming is effective for teachers’ TPACK development. Keywords: TPACK, In-service teacher, Programming, TPACK-P, Educational program

scholarly journals The Management and Outcome of Higher Order Multifetal Pregnancies: Obstetric, Neonatal and Follow-up Data

Twin Research ◽  
2001 ◽  
Vol 4 (1) ◽  
pp. 4-11
Author(s):  
Mark H. Yudin ◽  
Elizabeth V. Asztalos ◽  
Ann Jefferies ◽  
Jon F.R. Barrett
Keyword(s):  
Statistical Analysis ◽  
Motor Skills ◽  
Gestational Age ◽  
Neurodevelopmental Outcome ◽  
Higher Order ◽  
Neurodevelopmental Outcomes ◽  
Significant Difference ◽  
Before And After

AbstractThe objective of this study was to describe current obstetric, neonatal, and long-term neurodevelopmental outcomes of higher order multifetal gestations (≥ 3 fetuses) in the 1990s. We also intended to identify a target gestational age at which neonatal and neurodevelopmental morbidities are low. Records from all multifetal pregnancies (≥ 3 viable fetuses ≥ 20 weeks gestation) delivered at the two perinatal centers in Toronto, Ontario, Canada during the study period (January 1, 1990–December 31, 1996) were reviewed. Data were collected on obstetric, neonatal, and long-term neurodevelopmental outcomes. Follow up data were gathered regarding the presence of a severe deficit in four categories (vision, hearing, cognition, and motor skills). Statistical analysis was performed to determine a gestational age at which a significant decrease in deficit occurred. During the study period 165 multifetal pregnancies were delivered. This resulted in 511 fetuses, of which 496 were live births. Of these 496 infants, 453 survived to discharge. Follow up data were obtained on 332 (73.3 per cent) infants. Infant survival increased with gestational age, and was approximately 90 per cent or greater at 26 weeks or more. Of all infants followed, the proportion of those without deficit increased with increasing gestational age, such that the per cent without deficit was 96.9 at 31 weeks or greater. Of all infants followed, 301 (90.7 per cent) had no deficit. Statistical analysis revealed a significant difference in long-term neurodevelopmental outcome between infants born before and after 28 weeks gestation. The incidence of a major deficit was 44.1 per cent for those born earlier than and 5.4 per cent for those born later than this gestational age (p = 0.001). In our cohort, survival figures were high. Even in lower gestational groupings, survival was high, but not without serious concerns about severe morbidity. This information is useful when counseling parents of higher order multifetal pregnancies.

scholarly journals Effect of glide path on transportation promoted by NiTi and M-Wire instruments

2018 ◽  
Vol 21 (1) ◽  
pp. 104
Author(s):  
Tatiane Pires Nogueira ◽  
Ellen Roberta Lima Bessa ◽  
Eduardo Da Costa Nunes ◽  
André Augusto Franco Marques ◽  
Lucas Da Fonseca Roberti Garcia ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Root Canal ◽  
Polyester Resin ◽  
Root Canal Preparation ◽  
Root Canals ◽  
Path Creation ◽  
Dental Instruments ◽  
Glide Path ◽  
Significant Difference ◽  
Before And After

<p><strong>Objective:</strong> To evaluate the effect of glide path creation on transportation promoted by NiTi and M-Wire instruments. <strong>Material and Methods: </strong>Sixty polyester resin blocks containing a simulated root canal were distributed into four groups (n=15), according to the protocols/systems used for root canal preparation: GPR group - glide path + Revo-S system; R group - no glide path + Revo-S system; GPPN group - glide path + ProTaper Next system and PN group - no glide path + ProTaper Next system. Root canals were photographed before and after preparation, and the images were superimposed to evaluate the transportation at the apical, middle and coronal thirds. The time spent to perform preparation was also measured (seconds). Data were submitted to the non-parametric Kruskal-Wallis test (p&lt;0.05) for statistical analysis. <strong>Results:</strong> In the apical third, there was no significant difference among groups (p&gt;0.05). GPR and R groups were similar in the middle third (p&gt;0.05). However, the transportation value in GPR group was statistically higher in comparison with GPPN and PN groups (p&lt;0.05). In the coronal third, GPR and R groups were similar (p&gt;0.05). Only R group presented significant difference in comparison with GPPN and PN groups (p&lt;0.05). There was no difference among groups about time spent to perform preparation (p&gt;0.05). <strong>Conclusion:</strong> None of the systems were capable of maintaining the original trajectory of the simulated root canal, and the glide path had no effect on the transportation promoted by instruments.</p><p><strong>Keywords</strong></p><p>Dental instruments; Endodontics; Root canal preparation.</p>

scholarly journals USING VIDEO BLOG IN TEACHING SPEAKING

2019 ◽  
Vol 1 (1) ◽  
pp. 13
Author(s):  
Muhammad Jahid Marzuki ◽  
Sitti Nurpahmi
Keyword(s):  
Statistical Analysis ◽  
English Education ◽  
Sampling Technique ◽  
Education Department ◽  
Speaking Test ◽  
Significant Difference ◽  
Before And After ◽  
Final Score ◽  
Speaking Performance ◽  
Academic Year

The objective of the research is to find out whether or not video blog can improve the speaking ability of the students of English Education Department of FTK UINAM in academic year 2017/2018.  The researcher applied pre-experimental method, with one group pretest and posttest design which employed speaking test to find out the students’ speaking performance in terms of accuracy. The sample consisted of 20 students used purposive sampling technique taken from the population of the second semester students of Sulawesi Flight. The result of the data analysis indicated that there was significant difference of students’ speaking performance before and after being trained through video blog. It is proved by result of statistical analysis of the level significance 0.05 with degree of freedom (df) =  N-1 = 20-1 = 19 which indicated that t-test value of final score I speaking ability (13.309) was greater than t-table (2.093). Therefore, video blog can improve speaking performance of the students.

scholarly journals Different fabrication techniques of implant-supported prostheses

2019 ◽  
Vol 18 ◽  
pp. e191573
Author(s):  
Silas Monteiro Borges ◽  
Stephanie Francoi Poole ◽  
Izabela Cristina Maurício Moris ◽  
Aloísio Oro Spazzin ◽  
Adriana Cláudia Lapria Faria ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Computer Aided Design ◽  
Fracture Load ◽  
Fracture Pattern ◽  
Thermomechanical Cycling ◽  
Significant Difference ◽  
Computer Aided ◽  
Before And After ◽  
Cad Cam ◽  
Manufacturing Techniques

Aim: This study evaluated the mechanical behavior of implant-supported crowns obtained by different fabrication technique after thermomechanical cycling. Methods: Thirty-two external hexagon dental implants were divided into four groups (n=10): CC – conventional casting with torch; EI – electromagnetic induction casting; PL – plasma casting; and CAD-CAM – milling through computer-aided design and computer-aided manufacturing. Vickers microhardness of the specimens were made before and after the thermomechanical cycling, and then subjected to fracture load. Fracture pattern was evaluated. Results: No significant difference was observed comparing the microhardness before and after thermomechanical cycling. CAD-CAM group presented significant lower microhardness than the other groups. No significant statistical difference was showed on fracture load between the groups. The CAD-CAM and PL presented lower number of failure by plastic deformation. Conclusion: The manufacturing techniques affected the mechanical behavior and the failure pattern of implant-supported crowns tested.

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