scholarly journals Influence of Antimicrobial Nanoparticles on Flexural Strength and Hardness of Polymethylmethacrylate

2021 ◽  
Vol 9 (D) ◽  
pp. 314-318
Author(s):  
Mennatullah Khalil ◽  
Lamis Enaba
Keyword(s):  
Graphene Oxide ◽  
Flexural Strength ◽  
Pairwise Comparison ◽  
Graphene Oxide Nanosheets ◽  
Significance Level ◽  
Tio2 Nps ◽  
Antimicrobial Nanoparticles ◽  
Kolmogorov Smirnov ◽  
Group A ◽  
Group B

BACKGROUND: Polymethylmethacrylate (PMMA) is commonly used for dental appliances but has several shortcomings that could benefit from improvement with the use of nanoparticles (NPs). AIM: The purpose of this study was to modify PMMA with three different antimicrobial NPs; Graphene oxide nanosheets (nGO), Titanium dioxide NPs (TiO2 NPs) and curcumin (CUR)-loaded graphene oxide nanosheets alone, and in combination and assess the flexural strength and hardness of the different groups. MATERIALS AND METHODS: The material used in this study was chemically cured PMMA that was modified with nGO, TiO2 NPs and GOCUR alone and in combination to give 6 groups; Group A: PMMA, Group B: PMMA with nGO, Group C: PMMA with TiO2 NPs, Group D: PMMA with TiO2 and GO NPs, Group E: PMMA with GOCUR, and Group F: PMMA with TiO2 NP, and GOCUR. The Six groups were tested for flexural strength and hardness. Statistical analysis was and data were expressed as means and standard deviation. Data was explored for normality using the Kolmogorov-Smirnov test of normality. The ANOVA test was used to compare between groups, followed by Bonferroni’s post hoc test for pairwise comparison. The significance level was set at p ≤ 0.05. RESULTS: The highest flexural strength was recorded in Group C (52.26 ± 5.48 MPa) and the lowest value was in Group A (24.94 ± 5.37 MPa). The highest hardness was recorded in Group F (23.29 ± 0.8 HV) and the lowest value was in Group A (15.88 ± 1.02 HV). CONCLUSION: The modification of PMMA with NPs with proven antimicrobial activity can increase the flexural strength and hardness of the material. GO, TiO2 and, GOCUR NPs were each used alone and in different combinations, and all the groups displayed higher flexural strength and hardness than the unmodified PMMA.

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 < 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>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 In vitro Comparison of Apically Extruded Debris during Root Canal Retreatment with Rotary and Reciprocating Systems

2019 ◽  
Vol 13 (1) ◽  
pp. 488-492
Author(s):  
María J. Burbano Balseca ◽  
Silvana B. Terán Ayala ◽  
Fábio D. da Costa Aznar ◽  
Adriana R. de Freitas-Aznar ◽  
Guillermo M. Aguirre Balseca ◽  
...  
Keyword(s):  
Similar Amount ◽  
Hybrid Technique ◽  
Significance Level ◽  
Sealing Material ◽  
Apical Extrusion ◽  
Root Canal Retreatment ◽  
Group A ◽  
Group B ◽  
Reciprocating Systems

Introduction: The extrusion of apical detritus during the retracting procedure is very important, as, besides eliminating materials of radicular obturation, aggressive agents and products such as the remains of dentin taken out, and microorganisms are generally located in tissue around the roots, producing undesired effects, such as inflammation, acute pain, post-operatory pain and delays in the periapical treatment. Objective: To determine the amount of apically extruded detritus using rotary and reciprocating retreatment systems. Methodology: An experimental comparative study as conducted in which 40 single-rooted human first premolars were analyzed. The instruments used were ProTaper Universal files up to F3 and sodium hypochlorite, and the sealing was made through the hybrid technique Tager. They were then kept at 37ºC and 100% of humidity for 15 days so that the sealing material would seal. For the retracting procedure, experimental tubes previously weighted were used. The sample was divided randomly into two groups of 20 pieces. Group A: ProTaper R, and group B: Reciproc. Then, the irrigating material (distilled water) was evaporated from the tubes for 12 hours in a stove at 105ºC, and the experimental tubes were weighted in an analytical precision weighing scale 10-5g. The data was analyzed through the T Student with a significance level of 5%. Results: Results indicated that groups A and B, retreatment with rotational ProTaper R and reciprocating retreatment system (Reciproc) showed a similar difference of initial and final weights, indicating similar apical extrusion of detritus. Conclusion: Both systems extruded a similar amount of detritus during the retreatment procedures.

PENGARUH KOMBINASI EKSTRAK JERUK BRASTAGI DAN WORTEL PER ORAL SEBELUM AKTIVITAS FISIK TERHADAP PENURUNAN KADAR MDA PLASMA MENCIT SETELAH AKTIVITAS FISIK

2017 ◽  
Vol 1 (1) ◽  
pp. 41
Author(s):  
Nurvidya Rachma Dewi ◽  
Ambrosius Purba ◽  
Beltasar Tarigan
Keyword(s):  
Physical Activity ◽  
Free Radicals ◽  
Cellular Level ◽  
Not Given ◽  
Time Intervals ◽  
Kolmogorov Smirnov ◽  
Group A ◽  
The Difference ◽  
Group B ◽  
Per Oral

Aerobic metabolism in the cellular level generates free radicals. Under normal condition,theres balance between free radicals and endogenous antioxidants. Excessive amount of freeradicals impair DNA, protein, fat, etc. The level of free radicals can be known by measuringplasma malondialdehyde level. Combination of Brastagis oranges and carrots juice asexogenous antioxidants supplementation expected to decrease free radicals level . The aim of thisstudy is to investigate the difference of plasma MDA level during several time intervals on micewhich is given and not given combination of Brastagis oranges and carrots juice before physicalactivity using mices treadmill for 20 minutes. The research method used in this study is anexperimental laboratory study. The objects of this study are 40 mice (mus musculus), whitecolored, male, weighting 25-30 grams, which is randomly chosen. The objects are divided into 2groups, Group A : 20 mice (given combination of Brastagis oranges and carrots juice beforephysical activity using mices treadmill) and group B : 20 mice (not given combination ofBrastagis oranges and carrots juice before physical activity using mices treadmill). Group Aare divided into 5 subgroups: A1 (measurement of plasma MDA level at 0 minute after treadmill),A2 (measurement of plasma MDA level at 15 minutes after treadmill), and A3 (measurement ofplasma MDA level at 30 minutes after treadmill), A4 (measurement of plasma MDA level at 60minutes after treadmill), and A5 (measurement of plasma MDA level at 240 minutes aftertreadmill). The same procedures are employed for the group B. Plasma MDA level measuredafter doing physical activity using mice treadmill. The homogenity of the result then was testedusing Levenes test and the normality of the result was tested using Kolmogorov-smirnov test (p>0.05). Further, the data was analyzed using independent t-test (p?0.05), one-way ANOVA(p?0.05) then Duncans test were used. The results reveal significant lowering plasma MDAconcentration in mice receiving combination of Brastagis oranges and carrots juice beforephysical activity, which is measured during several time intervals : 0,15,30,60, and 240 minutesafter physical activity than in mice not receiving combination of Brastagis oranges and carrotsjuice before physical activity. The MDA level differences between groups which is given and notgiven combination of Brastagis orange and carrots juice before physical activity measuredduring several intervals are 11,44% (0,8920 vs 1,0071) measured 0 minute after physical activity,15,47% (0,7902 vs 0,9348) measured 15 minutes after physical activity, 14,42% (0,7473 vs0,8732) measured 30 minutes after physical activity, 11,35% (0,6696 vs 0,7554) measured 60minutes after physical activity, and 13,60% (0,5786 vs 0,6696) measured 240 minutes afterphysical activity.The conclusion of the study suggested that combination of Brastagis orange andcarrots juice supplementation has lowering effect toward plasma MDA level measured duringseveral time intervals.

scholarly journals Apical Debris Extrusion by Adaptive Root Canal Instrumentation in Oval Canals: Full-Sequence SAF System vs. the XP-Endo Shaper Plus Sequence

2020 ◽  
Vol 10 (16) ◽  
pp. 5684 ◽  
Author(s):  
Ajinkya M. Pawar ◽  
Bhaggyashri A. Pawar ◽  
Anuj Bhardwaj ◽  
Alexander Maniangat Luke ◽  
Zvi Metzger ◽  
...  
Keyword(s):  
Root Canal ◽  
Significance Level ◽  
Full Sequence ◽  
Apical Extrusion ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Stage 1 ◽  
Two Stages ◽  
Root Canal Instrumentation

Apical extrusion of debris (AED) by the full sequence of the self-adjusting file (SAF) system was compared with that of the XP-endo shaper plus sequence. Sixty permanent mandibular incisors were randomly assigned to two groups (n = 30) for root canal instrumentation: Group A: Stage 1—pre-SAF OS, pre-SAF 1 and pre-SAF 2 files, followed by Stage 2—1.5 mm SAF; and Group B: Stage 1— hand K-file 15/0.02, followed by Stage 2—XP-endo shaper and Stage 3—XP-endo finisher. The AED produced during instrumentation at each stage was collected in pre-weighed Eppendorf tubes. The weights of AED by the two methods were compared using t tests with significance level set at 5%. Group A produced significantly less total AED than Group B (p < 0.001), with no significant difference in debris extrusion between the two stages (p = 0.3014). Conversely, in Group B, a significant difference was noted between Stage 1 and Stages 2 and 3 (p < 0.01), with no significant difference between Stages 2 and 3 (p = 0.488). Both sequences resulted in measurable amounts of AED. Each phase, in either procedure, made its own contribution to the extrusion of debris.

scholarly journals Comparative study of knowledge about oral cancer among undergraduate dental students

2016 ◽  
Vol 14 (3) ◽  
pp. 338-345
Author(s):  
Samara Ribeiro da Silva ◽  
Yara Juliano ◽  
Neil Ferreira Novo ◽  
Ilan Weinfeld
Keyword(s):  
Risk Factors ◽  
Oral Cancer ◽  
Undergraduate Students ◽  
Dental Students ◽  
Clinical Aspects ◽  
Significance Level ◽  
First Semester ◽  
Group A ◽  
Group B ◽  
Self Examination

ABSTRACT Objective: To evaluate and compare the knowledge of dental undergraduate students about oral cancer. Methods: The students were divided into two groups according to semester attended in the undergraduate course: Group A, the first semester; and Group B, seventh semester. They were asked to answer a questionnaire about epidemiology, risk factors, clinical aspects, therapeutic solutions and oral self-examination. For statistical analysis, the Fisher's exact test, the Cochran's G test and Kendall's concordance test were used, with significance level set at 0.05. Results: Regarding the prevalent sex, only 8.0% of Group A and 56.0% of Group B judged males as the frequent affected by the disease (p=0.0006). In terms of age, 84.0% of the Group B and 44.0% of the Group A estimated that most cases were diagnosed over 40 years (p=0.0072). Smoking was identified as the major risk factor for 64.0% and 91.6% of Groups A and B, respectively (p=0.0110). On issues related to sex, ethnicity, age, risk factors, self-examination, treatment, professional responsible for treatment and profile of an individual with the disease, the seventh-semester showed significantly higher correct answer percentages than first-semester undergraduates. Conclusion: There was significant correlation between the right and wrong answers given by first and seventh semester students, making necessary a specific approach directed to their lack of knowledge.

scholarly journals Effects of Transcutaneous Electrical Acustimulation on Refractory Gastroesophageal Reflux Disease

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Li-na Meng ◽  
Shanshan Chen ◽  
Jiande D. Z. Chen ◽  
Hai-feng Jin ◽  
Bin Lu
Keyword(s):  
Gastroesophageal Reflux Disease ◽  
Gastroesophageal Reflux ◽  
Reflux Disease ◽  
Pairwise Comparison ◽  
Acid Reflux ◽  
Weak Acid ◽  
Before And After ◽  
Group A ◽  
Impedance Monitoring ◽  
Group B

Objective. To investigate effects and possible mechanisms of transcutaneous electrical acustimulation (TEA) performed by a wearable watch-size stimulator for refractory gastroesophageal reflux disease (RGERD).Methods. Twenty patients diagnosed as RGERD were enrolled in the study and randomly divided into four groups: esomeprazole group (Group A), esomeprazole combined with TEA group (Group B), esomeprazole combined with sham-TEA group (Group C), and esomeprazole combined with domperidone group (Group D). HRM and 24 h pH-impedance monitoring and GerdQ score were used to measure related indexes before and after treatment.Results. (1) TEA significantly increased LESP, compared with PPI treatment only or PPI plus sham-TEA. After pairwise comparison, LESP of Group B was increased more than Group A (P=0.008) or Group C (P=0.021). (2) PPI plus TEA decreased not only the number of acid reflux episodes but also the number of weak acid reflux episodes (P=0.005). (3) Heartburn and reflux symptoms were improved more with PPI + TEA than with PPI treatment only or PPI plus sham-TEA (GerdQ scores,P=0.001).Conclusion. TEA can improve symptoms in RGERD patients by increasing LESP and decreasing events of weak acid reflux and acid reflux; addition of TEA to esomeprazole significantly enhances the effect of TEA.

scholarly journals Lusutrombopag is effective and safe in patients with chronic liver disease and severe thrombocytopenia: a multicenter retrospective study

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Hiroaki Nomoto ◽  
Naoki Morimoto ◽  
Kouichi Miura ◽  
Shunji Watanabe ◽  
Yoshinari Takaoka ◽  
...  
Keyword(s):  
Platelet Count ◽  
Liver Disease ◽  
Chronic Liver Disease ◽  
Platelet Transfusion ◽  
Chronic Liver ◽  
Severe Thrombocytopenia ◽  
Invasive Procedures ◽  
Significance Level ◽  
Group A ◽  
Group B

Abstract Background Chronic liver disease (CLD) is often complicated by severe thrombocytopenia (platelet count < 50,000/µL). Platelet transfusion has been a gold standard for increasing the platelet count to prevent hemorrhagic events in such patients. Lusutrombopag, a thrombopoietin receptor agonist, can increase the platelet count in such patients when invasive procedures are scheduled. Former studies on lusutrombopag included patients with a platelet count of > 50,000/µL at baseline: the proportions of patients who did not require platelet transfusion were 84–96%, which might be overestimated. Methods The efficacy and safety of lusutrombopag were retrospectively investigated in CLD patients with platelet count of < 50,000/µL, a criterion for platelet transfusion, in real-world settings. We examined the proportion of patients who did not require platelet transfusion in 31 CLD patients, which exceeded a minimum required sample size (21 patients) calculated by 80% power at a significance level of 5%. Lusutrombopag, 3 mg once daily, was administered 8–18 days before scheduled invasive procedures. Results Among 31 patients who received lusutrombopag, 23 patients (74.2%) patients showed a platelet count of ≥ 50,000/µL (Group A) and did not require platelet transfusion. The remaining 8 patients (25.8%) did not reached platelet ≥ 50,000/µL (Group B). The means of platelet increase were 38,000/µL and 12,000/µL in groups A and B, respectively. A low platelet count at baseline was a characteristic of patients in group B. Among 13 patients who repeatedly used lusutrombopag, lusutrombopag significantly increased the platelet count as the initial treatment. When all repeated uses of lusutrombopag were counted among these 13 patients, platelet transfusion was not required in 82.1% (23/28) of treatments. Although one patient showed portal thrombosis after lusutrombopag treatment, the thrombosis was disappeared by anticoagulant treatment for 35 days. The degree of platelet increase with lusutrombopag was larger than that in their previous platelet transfusion. Conclusions The proportion of patients who did not require platelet transfusion was 74.2%, which is smaller than that in former studies which included CLD patients with a platelet count of > 50,000/µL. However, lusutrombopag is effective and safe for CLD patients with a platelet count of < 50,000/µL.

scholarly journals Mechanical Properties and Shrinkage Behavior of Concrete-Containing Graphene-Oxide Nanosheets

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 590 ◽  
Author(s):  
Zengshun Chen ◽  
Yemeng Xu ◽  
Jianmin Hua ◽  
Xu Wang ◽  
Lepeng Huang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Graphene Oxide ◽  
Flexural Strength ◽  
Elasticity Modulus ◽  
Shrinkage Strain ◽  
Graphene Oxide Nanosheets ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Dry Shrinkage ◽  
Shrinkage Behavior

Graphene oxide (GO) has been widely used as an additive due to its numerous unique properties. In this study, the compressive strength, flexural strength and elasticity modulus of concrete containing 0.02 wt%, 0.05 wt % and 0.08 wt % GO, and its dry shrinkage performance have been experimentally investigated. After the sample preparation, apparatus for compression test and flexural test were used to test the relevant properties of concrete containing GO. The dial indicators were used to measure the shrinkage of samples. The results indicate that GO can considerably improve the compressive strength, flexural strength, and elasticity modulus of concrete at the concrete age of 28 days by 4.04–12.65%, 3.8–7.38%, and 3.92–10.97%, respectively, which are substantially smaller than the increment at the age of 3 d by 5.02–21.51%, 4.25–13.06%, and 6.07–27.45% under a water-cement ratio of 0.35. It was also found that GO can increase the shrinkage strain of concrete. For example, at the age of 60 days, 0.02 wt%, 0.05 wt% and 0.08 wt% GO can increase the shrinkage strain of ordinary concrete by 1.99%, 5.79% and 7.45% respectively under a water-cement ratio of 0.49. The study has advanced our understanding on mechanical and shrinkage behavior of concrete containing GO.

Effect of Modification of Aluminum Borate Whiskers with Three Methods on Flexural Properties of Dental Resin Composites

2013 ◽  
Vol 364 ◽  
pp. 687-691
Author(s):  
Yan Bo Yuan ◽  
Xing Xing Li ◽  
Wen Yun Zhang ◽  
Qing Hua Chen ◽  
Yu Hong Xiao ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Sol Gel ◽  
Flexural Properties ◽  
Resin Composites ◽  
Dental Resin ◽  
Dental Resin Composites ◽  
Aluminium Borate ◽  
Significant Difference ◽  
Group A ◽  
Group B

This study aimed to compare three different methods for the modification of aluminium borate whiskers and investigate the effect of aluminium borate whiskers composites on flexural properties of dental resin composites. Method A was to mix aluminium borate whiskers and silicon dioxide (SiO2) nanoparticles directly. Method B was to modify the mixture of aluminium borate whiskers and SiO2nanoparticles with sol-gel process of tetraethoxysilane (TEOS). Method C was to modify the aluminium borate whiskers with SiO2nanoparticles which were repaired by sol-gel method of TEOS. The effects of the three methods were characterized by the TEM and SEM. There was a significant difference (p<0.05) in the flexural strength among three methods. Group C had a flexural strength of 149.59 ± 12.86 MPa (mean ± SD; n = 5), which is significantly higher than 95.28 ± 4.53 MPa for Group A and 123.14 ± 17.37 MPa for Group B. It is concluded that ceramic whisker reinforcement significantly improves the flexural properties of resin composites; different methods produce different effects.

scholarly journals Evaluation of the flexural strength and surface roughness of dental material after immersion in coffee

2021 ◽  
Vol 10 (3) ◽  
pp. e30510312486
Author(s):  
Patrícia Capellato ◽  
Ana Paula Rosifini Alves Claro
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Testing Machine ◽  
Dental Material ◽  
Bending Test ◽  
Control Group ◽  
Test Surface ◽  
Physiological Serum ◽  
Group A ◽  
Group B

This study was done in order to evaluate the changes in flexural strength and surface roughness in dental material restorations after immersion in coffee. Bars specimens (2mm x 2mm x 25 mm) of Z100 3M/ESPE were made according to ISO 4049 using aluminum molds. After curing, the specimens were then randomly divided into five groups and conditioned at 37°C in physiological serum. In all groups, except control, samples were immersed in coffee for ten minutes daily. In group A, the samples were immersed in coffee. For group B, after to be immersed in coffee, samples were immersed in distilled water for one minute. For group C, samples were immersed in mouthwash for one minute. For group D, samples were brushing for ten minutes, with load of 250g and 4250 cycles after all treatments the samples were stored in physiological serum again. In control group, samples were only stored in physiological serum. The five groups were then divided into 2 subgroups according storage time, six and nine weeks, respectively. Flexural strength was determined using three point bending test in a universal testing machine. All the tests were carried out at a room temperature and samples were maintained in physiological serum during the test. Surface roughness measurements were made using a surface roughness tester. All data were analyzed using one-way analysis of variance (ANOVA) followed by Dunnet tests. The ANOVA indicated no difference in the means of surface roughness and significant was observed for flexural strength between control group and one group (coffee).

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