scholarly journals TiO2-Nanofillers Effects on Some Properties of Highly- Impact Resin Using Different Processing Techniques

2018 ◽  
Vol 12 (1) ◽  
pp. 202-212 ◽  
Author(s):  
Hawraa Khalid Aziz
Keyword(s):  
Thermal Conductivity ◽  
Impact Strength ◽  
Color Stability ◽  
Acrylic Resin ◽  
Water Bath ◽  
Control Group ◽  
Significance Level ◽  
Significant Difference ◽  
And Control ◽  
The Impact

Background: The criteria of conventional curing of polymethyl methacrylate do not match the standard properties of the denture base materials. Objectives: This research was conducted to investigate the addition of TiO2 nano practical on impact strength, thermal conductivity and color stability of acrylic resin cured by microwave in comparison to the conventional cured of heat-polymerized acrylic resin. Materials and Methods: 120 specimens made of high impact acrylic resin were divided into two main groups according to the type of curing (water bath, microwave), then each group was subdivided into two groups according to the addition of 3% TiO2 nano-fillers and control group (without the addition of TiO2 0%). Each group was subdivided according to the type of test into 3 groups with 10 specimens for each group. Data were statistically analyzed using Student t-test to detect the significant differences between tested and control groups at significance level (P<0.05). Results: According to curing type methods, the results showed that there was a significant decrease in impact strength of microwaved cured resin, but there was no significant difference in the thermal conductivity and color stability of resin. In addition, by using nanofiller, there was a significant increase in the impact strength and color stability with the addition of 3% TiO2 nanofillers, but no significant difference was found in the thermal conductivity of the acrylic resin. Conclusion: The microwave curing of acrylic resin had no change in the color stability and thermal conductivity in comparison to the water bath, but the impact strength was decreased. The addition of 3% TiO2 improved the impact and the color stability, but the thermal conductivity did not change.

scholarly journals The impact of using the strategy of self-questioning in the achievement of students in the fifth grade in mathematics: أثر استخدام استراتيجية التساؤل الذاتي في تحصيل طلاب الصف الخامس الابتدائي في مادة الرياضيات

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Abdul Latif Al-Zakri
Keyword(s):  
Achievement Test ◽  
Experimental Methodology ◽  
Fifth Grade ◽  
Control Group ◽  
Significance Level ◽  
Fifth Grade Students ◽  
Significant Difference ◽  
And Control ◽  
The Impact ◽  
Experimental Group

This study aimed to examine the impact of the use of self-questioning in the understanding of fifth grade students in mathematics material. The researcher used the experimental methodology for independent groups to investigate the impact of the independent variable, which is a self-questioning strategy on the dependent variable, which is understanding. The study sample consisted of 42 students from the fifth grade students from Khubayb bin Udai School in Riyadh; equally divided into two groups of 21 students in each group (experimental and control), and after making sure from groups' equivalence by applying the tools of the study, having been taught the experimental group by using self-questioning strategy, while the control group has been studied the unit by using the traditional method. After the completion of the study of prescribed content study, study tools (achievement test) were applied then. The results indicated to the presence of a statistically significant difference (at the significance level <0. 05) between the mean scores of the two groups' students (experimental and control) in achievement test posttest for the experimental group. Since the results of the study were positive in increasing the achievement, the researcher recommended the need to use self-questioning to raise the level of achievement of learners in mathematics material

IMPACT STRENGTH TEST ON ADDITION OF AGAVE SISALANA FIBER AND E-GLASS FIBER IN ACRYLIC RESIN DENTAL PLATE REPAIR

2021 ◽  
Vol 17 (1) ◽  
pp. 49-55
Author(s):  
Ni Kadek Sugianitri ◽  
◽  
Suhendra Suhendra ◽  
Keyword(s):  
Impact Strength ◽  
Glass Fiber ◽  
Acrylic Resin ◽  
Control Group ◽  
Denture Base ◽  
Denture Plate ◽  
Significant Difference ◽  
The Impact ◽  
Agave Sisalana ◽  
Fiber Addition

Introduction: Acrylic resin is the most common material for the denture base because the acrylic resin has good esthetics, ease of processing, reparability, and inexpensive. A disadvantage of acrylic resin is that it is easy to be cracked. One of the ways to resolve this problem is by adding agave sisalana fiber and E-glass fiber. The purpose of this study was to find out the effect of the addition of agave sisalana fiber and E-glass fiber on the impact strength of an acrylic resin denture plate reparation. Material and Method: The experiment involved twenty-seven plates of heat-cured acrylic with the dimensions of 55x 10 x 10 mm with the 26 x 5 x 4 mm for the cavity to measure, each measurement divided into three groups, with nine samples for each group. The first group was a control group (without fiber), the second group was a group with agave sisalana fiber addition, the third group was a group with e-glass fiber addition. All plates were soaked in distillation water for one day at 37o C. Plates were tested for impact strength using the Charpy method. All data obtained were analyzed with one-way ANOVA followed by LSD (Least Significant Difference) with p<0,05. Result and Discussion: The result showed that the influences of impact strength between without fiber with agave sisalana fiber and E-glass fiber addition on acrylic denture reparation. Acrylic denture reparation in both fibers with concentration 3,3%, agave sisalana fiber has the highest impact strength rather than e-glass fiber. Conclusion: The conclusion of this study is that there is an increase in impact strength with agave sisalana fiber and E-glass fiber addition on acrylic denture reparation and agave sisalana fiber has the highest impact strength.

scholarly journals Influence of Processing Techniques on Microhardness and Impact Strength of Conventional and Reinforced Heat Cured Acrylic Resin: A Comparative Study

2021 ◽  
Vol 58 (3) ◽  
pp. 239-246
Author(s):  
Aisha Kiran ◽  
Faiza Amin ◽  
Muneeb A Lone ◽  
Imran Alam Moheet ◽  
Maham M Lone ◽  
...  
Keyword(s):  
Impact Strength ◽  
Acrylic Resin ◽  
Water Bath ◽  
P Value ◽  
Dry Heat ◽  
Heat Cure ◽  
Significant Difference ◽  
Group A ◽  
Processing Techniques ◽  
The Impact

This study determined and compared the influences of various processing techniques including air circulating oven (ACO), dry heat oven (DHO) and water bath (WB) on the impact strength (IS) and microhardness (HV) of the conventional heat cure acrylic resin (CHCAR) and rubber reinforced heat cure acrylic resin (RRHCAR). Samples were fabricated using CHCAR (control Group A; n=114) and RRHCAR (experimental Group B; n=114). Group A and B were further divided into subgroups according to processing techniques: ACO, DHO and WB (n=38 each) for both testing variables microhardness and impact strength (n=19 each). Charpy testing machine and Vickers microhardness tester were utilized. Analysis of variance was applied to determine the presence of significant differences among processing techniques while P-value ≤ 0.05 was considered as significant. Water bath (P-value [0.001) and DHO technique (p-value [0.001) showed significant differences between both groups� impact strength and microhardness. Microhardness of group A and B showed a significant difference (p-value 0.002) when processed by ACO. Impact strength and micro hardness were improved in RRHCAR compared to CHCAR processed by ACO and DHO in comparison to WB technique. Rubber reinforced heat cure acrylic resin revealed improvement in the impact strength and microhardness. The air circulating oven exhibited highest microhardness in both testing materials. Dry heat oven showed improved values of impact strength in conventional heat cure acrylic resin.

ENHANCEMENT OF DENTURE-BASED MATERIAL PMMA BY INCORPORATION OF SILANIZED HALLOYSITE NANOTUBES

2021 ◽  
Vol 74 (9) ◽  
pp. 2293-2296
Author(s):  
Rafah Habib Abdul Amir
Keyword(s):  
Impact Strength ◽  
Base Material ◽  
Hardness Test ◽  
Acrylic Resin ◽  
Halloysite Nanotubes ◽  
Control Group ◽  
Transverse Strength ◽  
Comparison Results ◽  
Significant Difference ◽  
The Impact

The aim: This study evaluates the effect of adding silanized halloysite nanotubes to the polymethylmethacrylate (PMMA) resin on its hardness, impact strength, transverse strength. Materials and methods: Three groups of acrylic resin were prepared, one group without HNTs, was used as a control group (A). The other two groups contained 0.3% (B), 0.6% wt of silanized halloysite nanotubes (C). For each one, hardness, impact strength and transverse strength were measured. One-way ANOVA and Tukey’s test were used for comparison. Results: Regarding to the impact test, there was no significant difference between 0.3% concentration and the pure (control) group while 0.6% concentration had significant decrease compared to the pure group and so between the 0.3% group 0.6% group. For the hardness test, the 0.3% group had no significant difference with the pure group and a significant difference between group 0.6% group and the pure group while there was a no significant decrease between the 0.3% and 0.6% group with the higher hardness mean in the 0.3% compared to 0.6% group. For the transverse strength, both 0.3% wt concentration and 0.6% concentration showed significant difference compared to the pure group and also between each other with the lowest impact strength in 0.6% group followed by 0.3% group with the highest transverse strength in the pure group. Conclusions: The silanation of halloysite nanotubes reduces the mechanical properties of the heat-cured acrylic denture base material. The more concentration of silanazed halloysite nanotubes is added, the more weakening occurs in the acrylic material relating to the hardness, transverse strength and impact strength.

scholarly journals The effect of teaching self- questioning strategy in increasing the achievement of sixth primary students in science in private education schools in Dammam: أثر التدريس باستراتيجية التساؤل الذاتي في زيادة تحصيل طالبات السادس الابتدائي في العلوم بمدارس التربية الأهلية بالدمام

2019 ◽  
Vol 3 (29) ◽  
Author(s):  
Nujoom Abdullah alsabey
Keyword(s):  
Sixth Grade ◽  
Achievement Test ◽  
Experimental Methodology ◽  
Control Group ◽  
Significance Level ◽  
Significant Difference ◽  
Sixth Grade Students ◽  
And Control ◽  
The Impact ◽  
Experimental Group

This study aimed to examine the impact of the use of self-questioning in the understanding of sixth grade students in Science Course. The researcher used the experimental methodology for independent groups to investigate the impact of the independent variable, which is a self-questioning strategy on the dependent variable, which is understanding. The study sample consisted of 40 students from the sixth grade students from National Education Schools in Dammam; equally divided into two groups of 20 students in each group (experimental and control), and after making sure from groups' equivalence by applying the tools of the study, having been taught the experimental group by using self-questioning strategy, while the control group has been studied the unit by using the traditional method. After the completion of the study of prescribed content study, study tools (achievement test) were applied then. The results indicated to the presence of a statistically significant difference (at the significance level <0. 05) between the mean scores of the two groups' students (experimental and control) in achievement test posttest for the experimental group. Since the results of the study were positive in increasing the achievement, the researcher recommended the need to use self-questioning to raise the level of achievement of learners in Science Course.    

Resorbable Collagen Barrier Impeding the Extrusion of Obturating Material in Primary Molars Undergoing Resorption – A Randomized Clinical Trial

2021 ◽  
Vol 45 (5) ◽  
pp. 312-316
Author(s):  
Mishra Neha Sanjeev ◽  
Harsimran Kaur ◽  
Sandeep Singh Mayall ◽  
Rishika ◽  
Ramakrishna Yeluri
Keyword(s):  
Test Group ◽  
Primary Molars ◽  
Control Group ◽  
Chi Square ◽  
Significance Level ◽  
Significant Difference ◽  
Chi Square Test ◽  
Group A ◽  
Group B ◽  
And Control

Objective: To evaluate the effectiveness of placing a resorbable collagen barrier in impeding the extrusion of obturation material in primary molars undergoing resorption. Study design: All the 94 canals in 47 mandibular molars were allocated to 2 groups- Group ‘A’- 47 canals with collagen barrier (Test group) and Group ‘B’- 47 canals without collagen barrier (Control group) based on randomization protocol. Pulpectomy was performed and obturation of both test and control canals were radiographically assessed. Pearson’s chi – square test was applied to analyze the results. The significance level was predetermined at p &lt; 0.05. Results: Among the test group, 93.6% of the canals showed no extrusion while, 6.4% showed visible extrusion of the material outside the apex. In the control group, 83% showed no extrusion whereas 17% of the canals showed visible extrusion outside the apex. But no significant difference was noted (p&gt;0.05). Conclusion: The placement of resorbable collagen barrier in the apical third of the canal prevented the extrusion of obturating material beyond the apex in resorbing primary molars.

scholarly journals Evaluation of color change in acrylic and bisacrylic resin resins in different solutions

2018 ◽  
Vol 5 (4) ◽  
pp. 76
Author(s):  
Mone Laiz Bortoli ◽  
Cristina Von Appen ◽  
Camila Longoni ◽  
Carmen Beatriz Borges Fortes ◽  
Jefferson Tomio Sanada
Keyword(s):  
Color Change ◽  
Color Stability ◽  
Acrylic Resin ◽  
Color Variation ◽  
Color Reading ◽  
Control Group ◽  
Color Changes ◽  
Significant Difference ◽  
Prosthesis Material ◽  
Chlorhexidine Solution

Aim: This work aimed to evaluate the color stability of an acrylic resin chemically activated (ARCA) using different handling techniques, and a bisacrylic resin when exposed to different pigmentation solutions.Material and Methods: Silicon matrixes were confectioned (10x10x3mm) to be used as specimens. The groups were designed as follows: Group Pot, Group Brush, Group Manufacturer and Group Bisacrylic (n=18). Each group was exposed to three different pigmentation solutions: distilled water, coke and chlorhexidine digluconate 0.12%. Three readings were performed for each specimen using a spectrophotometer, and the evaluations were carried out in three different time. After the color reading, three averages and the standard deviation of variation were performed after 24 hours (T1), 7 days (T2) and 14 days (T3). Data were submitted to the ANOVA and 2 criteria and Tukey (P<0.05) in the statistical software SSPS 18 for Macintosh (SPSS Inc., Chicago, USA).Results: When compared the solutions in each group of material, there was no statistically significant difference, except for T3, where the group Dencor Brush and Bisacrylic demonstrated higher color variation in all the solutions, even in the control group, and the values in Chlorhexidine higher than the other, showing greater instability after 14 days.Conclusions: With the results, bisacrylic resin used as provisory prosthesis material presents greater color instability than the ARCA, when submitted to different solutions. Bisacrylic resin and Dencor Brush present significantly visible color changes in chlorhexidine solution after 14 days. All the materials in coke solution present homogeneity in the color change after 7 days exposition to the solution, with no visible color change.

scholarly journals What is the impact of methotrexate on liver in patients with juvenile idiopathic arthritis? Results of liver SWE performed in a single centre

2021 ◽  
Author(s):  
Vildan Güngörer ◽  
Mehmet Öztürk ◽  
Mustafa Yasir Özlü ◽  
Şükrü Arslan
Keyword(s):  
Juvenile Idiopathic Arthritis ◽  
Shear Wave Elastography ◽  
Term Therapy ◽  
Control Group ◽  
Significant Difference ◽  
Group 2 ◽  
Long Term Therapy ◽  
And Control ◽  
The Impact

ABSTRACT Objectives Long-term therapy with low-dose methotrexate (MTX) is widely used in treatment of rheumatic diseases, in children. The purpose of this study was to evaluate liver elasticity in patients with juvenile idiopathic arthritis (JIA) who received MTX and compare the results with control group. Methods Liver elasticity was evaluated with shear wave elastography (SWE) technique in 25 patients aged 3–17 years who were followed up with JIA and received MTX and compared with 25 healthy controls of the same age and weight. Factors that had an effect on liver elasticity were examined. Results The mean SWE value of patients was 2.64 ± 2.13 m/s and 24.10 ± 18.50 kPa, whereas 1.83 ± 0.16 m/s and 10.09 ± 1.83 kPa in control group. There was a significant difference in liver elasticity in the patient and control groups. When the patients were evaluated as Group 1 (&lt; 1000 mg) and Group 2 (≥ 1000 mg) according to the cumulative MTX dose, no significant difference was obtained. There was positive correlation between liver elasticity and weekly MTX dose and age. Conclusions Our study revealed that liver elasticity significantly decreased in patients who received MTX when compared with the control group. The elastography technique will be understood better over time and used safely in many areas.

scholarly journals The Impact of Smartboard on Preparatory Year EFL Learners’ Motivation at a Saudi University

2017 ◽  
Vol 8 (3) ◽  
pp. 172
Author(s):  
Waqar Ahmad ◽  
Zuraina Ali ◽  
Muhammad Aslam Sipra ◽  
Imtiaz Hassan Taj
Keyword(s):  
Teaching And Learning ◽  
Control Group ◽  
Efl Learners ◽  
Saudi Students ◽  
Significant Difference ◽  
Literature Reviews ◽  
Preparatory Year ◽  
And Control ◽  
The Impact ◽  
Experimental Group

Smartboards, which are now widely used in the teaching and learning process in Saudi Arabia, have turned the traditional environments of the classrooms, especially the EFL classrooms to be more interesting and encouraging. Literature reviews suggest that Saudi students usually lack motivation for studying English as a foreign language. This study tends to investigate the impact of Smartboards on preparatory year EFL learners motivation at a Saudi university. Two intact groups were selected, in which one was termed as experimental and the second as control group. The experimental group was taught using the Smartboard while the control group was taught with the traditional whiteboard, pen and book method. The treatment was given for seven weeks. A questionnaire was administered to both the groups at the beginning and the end of the study. The data was analysed using the SPSS and the results showed that there was significant difference between the experimental and control groups in terms of motivation.  

scholarly journals Fracture Resistance of Immature Incisors Following Root Filling with Various Bioactive Endodontic Cements Using an Experimental Bovine Tooth Model

2019 ◽  
Vol 13 (02) ◽  
pp. 156-160 ◽  
Author(s):  
Pegah Sarraf ◽  
Mohammad Hossein Nekoofar ◽  
Mohammad Saeed Sheykhrezae ◽  
Paul M. H. Dummer
Keyword(s):  
Root Canal ◽  
Fracture Resistance ◽  
Acrylic Resin ◽  
Control Group ◽  
Control Groups ◽  
Cem Cement ◽  
Filling Materials ◽  
Gutta Percha ◽  
Significant Difference ◽  
And Control

Abstract Objective The aim of this study was to compare the fracture resistance of immature bovine roots when using ProRoot MTA, CEM Cement, and Biodentine as root filling materials. Materials and Methods An immature bovine tooth model was developed by removing the coronal and apical portions of 70 bovine incisors 8 mm above and 12 mm below the cementoenamel junction (CEJ). The specimens were then divided into five groups: ProRoot MTA, CEM Cement, Biodentine, gutta-percha/AH26 sealer, and control. All groups received a 5-mm apical plug with a temporary restorative material. Then, the remaining root canal space was filled with one of the afore-mentioned materials. After setting, the specimens were mounted in acrylic resin. Then, 3 mm coronal to the CEJ from the buccal side of the teeth and at a 135°angle to the long axis, the specimens were loaded until fracture. Results The specimens in the Biodentine (2196 N) and ProRoot MTA (2103 N) groups had significantly greater fracture resistance in comparison to the control group (p = 0.01). No significant difference was found between CEM Cement, gutta-percha and sealer AH26, and control groups. No significant differences occurred between the four experimental groups (p = 0.45). Conclusion Filling the root canal space with ProRoot MTA and Biodentine contributed to higher fracture resistance values.

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