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.

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 Mechanical Properties of Heat Cured Acrylic Resin Reinforced with Natural Sisal Fibers Powder

2021 ◽  
Vol 2114 (1) ◽  
pp. 012023
Author(s):  
Teba M. Hameed ◽  
Balqees M. Al-Dabbagh ◽  
Ragdaa K. Jasim
Keyword(s):  
Tensile Strength ◽  
Impact Strength ◽  
Flexural Strength ◽  
Acrylic Resin ◽  
Impact Testing ◽  
Bending Test ◽  
Heat Cure ◽  
Significant Difference ◽  
Sisal Fibers ◽  
The Impact

Abstract Materials and Methods: In total, 90 specimens were prepared to be used in the study. The specimens were divided into (3) main groups depended on the presence of sisal fibers powder, first group (30) specimens of heat cure PMMA without additives (control), second and third experimental groups of 60 specimens of heat cure PMMA with salinized sisal fibers powder with two different weight percentages (1 and 3%) wt. Three point bending test was used to measure the flexural strength of the specimens, while the impact strength was done by impact testing Charpy’s machine and tensile test was performed according to ASTM (D-638). Data analysis was performed using (ANOVA) test. The results of this study refer to a highly significant in the flexural strength and tensile strength of specimens reinforced with sisal fibers powder compared with control specimens. Non-significant difference was detected in impact strength among the reinforced groups and control gro. Reinforcement of acrylic resin with natural sisal fibers powder affects its flexural strength and tensile strength with non-significant in impact strength.

scholarly journals Clinical significance of prostatic-urethral angulation on the treatment outcome of patients with symptomatic benign prostatic hyperplasia treated with tamsulosin hydrochloride

2015 ◽  
Vol 87 (3) ◽  
pp. 238
Author(s):  
Hassan El-Tatawy ◽  
Tarek Gameel ◽  
Mohammed Abo El-enen ◽  
Ayman Hagras ◽  
Ayman Mousa ◽  
...  
Keyword(s):  
Benign Prostatic Hyperplasia ◽  
Clinical Significance ◽  
Treatment Efficacy ◽  
Specific Antigen ◽  
Prostatic Hyperplasia ◽  
Final Conclusion ◽  
P Value ◽  
Significant Difference ◽  
Group A ◽  
The Impact

Objectives: To evaluate the impact of the prostatic-urethral angulation (PUA) on the treatment efficacy of selective alpha-1A receptor blocker in male patients with lower urinary tract symptoms secondary to benign prostatic hyperplasia (LUTS/BPH). Materials and methods: A total of 80 patients with LUTS/BPH and with mean age 53.3 ± 6.3 (range 47-70) were included in our prospective comparative study. The patients were classified into 2 groups as a consecutive cases 40 in each one depending on the PUA either ≤ 35° (group A) or &gt; 35° (group B). PUA and different prostatic parameters were measured using transrectal ultrasound. Prostate-specific antigen (PSA), the International Prostate Symptom Score and quality of life score (IPSS/QoL score), maximum flow rate (Q<sub>max</sub>), and postvoid residual (PVR) volume were compared between the groups. The clinical significance of PUA was evaluated after 8 weeks of medical treatment with tamsulosin hydrochloride 0.4 mg daily. Results: Baseline evaluation (pre-treatment) for both groups were comparable to each other with no clinically significant difference regarding age, PSA, IPSS/QoL score, Qmax and PVR volume (P-value &gt; 0.05). Comparison of parameters after 8 weeks showed that tamsulosin hydrochloride improved the total IPSS and all subscores (P &lt; 0.001), QoL (P = 0.001), Q<sub>max</sub> (P = 0.002), and PVR (P = 0.04) in group A (Table 1). Conclusion: Tamsulosin hydrochloride appears to be less effective in improving IPSS/Qol score, Qmax and PVR in patients with lager PUA. The PUA might be a predictor for the treatment efficacy of α-blockers and more studies are warranted in the future before the final conclusion.

scholarly journals ADDITION OF RICE HUSK NANOCELLULOSE TO THE IMPACT STRENGTH OF RESIN BASE HEAT CURED

2021 ◽  
Vol 4 (3) ◽  
pp. 119
Author(s):  
Muhammad Aditya Ramadhan Hasran ◽  
Dian Noviyanti Agus Imam ◽  
Bambang Sunendar
Keyword(s):  
Impact Strength ◽  
Mechanical Strength ◽  
Rice Husk ◽  
Acrylic Resin ◽  
Control Group ◽  
P Value ◽  
Test Results ◽  
Nano Cellulose ◽  
Reinforcing Material ◽  
The Impact

Background: One of the materials for denture bases is heat-cured acrylic resin (PMMA). This material still lacks impact strength as a mechanical strength property. The addition of reinforcing material is known to increase the mechanical strength of PMMA. One of the reinforcing materials added to PMMA is nano cellulose from rice husks, one of the wastes from agricultural products. Purpose: This study aims to determine rice husk nano cellulose's addition to the PMMA denture base's impact strength. Method:  The research sample consisted of six groups, each group consisting of 8 samples selected by simple random. The PI, P2, P3, P4, P5, and K groups were PMMA with 1%, 2%, 3%, 4%, 5% nano cellulose, and without nano cellulose. Result: Mean impact strength test results were 41.50 x 10-3 ± 3.891 J / mm2 for P1, 44.13 x 10-3 ± 3,980 J / mm2 for P2, 45.63 x 10-3 ± 4,438 J / mm2 for P3, 46.87 x 10-3 ± 4,824 J / mm2 for P4, 49.12 x 10-3 ± 4.016 J / mm2 for P5 and 36.25 x 10-3 ± 1.982 J / mm2 for K. One way Anova test results with p-value of 0.000 indicates differences in the six groups (p<0.05). Conclusion: This study concludes that the impact strength value of PMMA with the addition of rice husk nano cellulose has increased compared to the control group without the addition of rice husk nano cellulose.

Impact of Whatsapp in improving learning among 9th semester MBBS students

2021 ◽  
Vol 19 (1) ◽  
pp. 27-30
Author(s):  
Y Satish Reddy ◽  
Keyword(s):  
Undergraduate Students ◽  
Control Group ◽  
P Value ◽  
Study Group ◽  
Opinion Poll ◽  
Didactic Teaching ◽  
Significant Difference ◽  
Group A ◽  
The Mean ◽  
The Impact

Background: Interactive Teaching learning can be used in clinical subjects like surgery for better participation of students as one-way didactic lectures do not involve active participation of students. WhatsApp is one of the most famous messaging services which everyone use and it is easy, cheaper, and faster. Objective: the purpose of the study was to study the impact of whatsapp in improving learning in general surgery among 9th semester medical students. Methods: This study was conducted among 9th semester MBBS students in Surgery department. Students were divided into group a (study group) and group b(control group) by a simple random sampling. Gastric cancer was discussed among students of both Groups through didactic teaching. after didactic teaching, only Group A students were exposed to social media type of learning, i.e., using WhatsApp, after the session a multiple-choice questionnaire having 10 MCQs was given to both groups and an additional poll was conducted among the Study-group students to assess their perception towards Whatsapp intervention. the mean score obtained by both the groups were compared with unpaired t test. P-value <0.05 is taken as statistically significant. Results: The mean (SD) score of the Study-group was 8.58(1.18) and the mean (SD) score of the Control-group was 5.41(1.32) and statistically significant difference was found between the two groups scores with a p-value less than 0.05 opinion poll found that the intervention of whatsapp among study group was effective. Conclusion: we observed that the usage of WhatsApp in addition to the didactic teaching was found advantageous and enhanced learning in undergraduate students

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 The Effect of Coca Cola Drink on the Impact Strength and Surface Roughness of Acrylic Denture Base

2018 ◽  
Vol 2 (2) ◽  
pp. 120-131
Author(s):  
Fahd Ikram
Keyword(s):  
Surface Roughness ◽  
Impact Strength ◽  
Plastic Material ◽  
Base Material ◽  
Control Group ◽  
Denture Base ◽  
Heat Cure ◽  
Base Resin ◽  
Group A ◽  
The Impact

Despite the development of many denture base material like chrome-cobalt, fluid and plastic material but the heat cure polymethylmethacrylate considered as the most widely used denture base material. The aims of this study to evaluate and compare the impact strength and surface roughness of heat cured denture base resin after immersing incoca-cola drink for two and four weeks. Methods: A total number of 40 samples were prepared, 30 samples for impact strength test and 10 samples for surface roughness test. The samples were divided into three group; A (control), B (2 weeks immersed in coca cola drink), and C (4 weeks immersed in coca cola drink). Result: Data analyzed by using SPSS software with ANOVA test indicated a non significant differences between the different tested groups, however the samples that were immersed in coca cola drink for 4 weeks revealed non dramatic increase in surface roughness, while the samples that were immersed for 2 weeks showed a non dramatic decrease in the impact strength. Conclusions: The coca cola drink non significantly caused dropping in the tested properties in comparison to the control group.

scholarly journals The Effect of Addition of Bambusa Arundinacea (Retz.) Willd. Fibers to Heat-Cured Acrylic Resin on Impact Strength

2018 ◽  
Vol 1 (2) ◽  
pp. 81
Author(s):  
Chanita Elonianty ◽  
Titien Hary Agustantina ◽  
Intan Nirwana
Keyword(s):  
Impact Strength ◽  
Low Cost ◽  
Acrylic Resin ◽  
Test Results ◽  
High Toughness ◽  
Significant Difference ◽  
Impact Tester ◽  
Strength Formula ◽  
The Impact ◽  
One Way Anova

Background: The prevalence of acrylic resin dentures fracture due to accidental drop is relatively high especially when it is being cleaned by patient. The effort to strengthen acrylic resin denture was done by adding Bambusa arundinacea (Retz.) Willd fibers, which was based on previous research. It has been proven that the addition of bamboo fiber to self-cured acrylic resin can increase the tensile strength. It has acceptable tensile properties, relatively low cost, high toughness, and good thermal properties. Purpose: To determine the impact strength of heat-cured acrylic resin after the addition of Bambusa arundinacea (Retz.) Willd. fibers at various lengths and weights. Methods: Bambusa arundinacea (Retz.) Willd. fibers with lengths of 2 mm, 6 mm, 12 mm and weights of 3wt%, 6wt%, 9wt% were added to heat-cured acrylic resin. The impact strength of heat-cured acrylic resin was tested using the Charpy method with mini impact tester KRY type. The test results were calculated using the impact strength formula. The research data were analyzed using one-way anova test and Tukey HSD test. Results: The data analysis showed that there was a significant difference in impact strength of heat-cured acrylic resin after the addition of Bambusa arundinacea (Retz.) Willd fibers. Conclusion: Addition of Bambusa arudinacea (Retz.) Willd. fibers increased the impact strength of heat-cured acrylic resin respective to the increment of length and weight of Bambusa arudinacea (Retz.) Willd. fibers.

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 Impact of an Educational Program on Medical Students’ Knowledge and Awareness of Elder Abuse

2021 ◽  
Vol 8 ◽  
pp. 238212052110164
Author(s):  
Abbie West ◽  
Cara Cawley ◽  
Elizabeth Crow ◽  
Alexis M. Stoner ◽  
Natalie M. Fadel ◽  
...  
Keyword(s):  
Medical Students ◽  
Educational Program ◽  
Survey Methodology ◽  
Elder Abuse ◽  
P Value ◽  
Significant Difference ◽  
Survey Results ◽  
Second Year ◽  
College Of Osteopathic Medicine ◽  
The Impact

Objective: Approximately 1 in 6 adults 60 and older have experienced a form of abuse in the past year. Many cases remain under-reported due to lack of knowledge and awareness. This study created an educational program on elder abuse for medical students to determine if participation would increase knowledge and awareness of elder abuse. Methods: This study used a pre and post survey methodology to evaluate students’ knowledge and awareness of elder abuse before and after participating in this educational program. Sixty first and second year osteopathic medical students at the Edward Via College of Osteopathic Medicine, Carolinas Campus participated in this study. Students were emailed a pre-survey to evaluate their pre-existing knowledge and awareness. The survey was, previously created by the Student Training on Preventing Domestic Violence (STOP-DV) team using validated measures. Participants then attended educational events about various forms of elder abuse and recognizing its associated signs, and afterward completed the post-survey. The results were compared using t-tests to determine if there was a significant difference. Results: First and second year students differed significantly in pre-survey results of knowledge but not post-survey results. The results showed a significant difference in overall mean knowledge ( P-value < .001) and awareness scores ( P-value < .001) in all students. Conclusion: These results suggest education on elder abuse can enable future physicians to better recognize, understand, and support older adults regarding elder maltreatment.

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