Analysis of Color and Hardness of a Medical Silicone with Extrinsic Pigmentation after Accelerated Aging

Abstract Objective The aim of this study is to evaluate the color alteration and shore A hardness of a medical silicone with extrinsic pigmentation, before and after accelerated aging. Materials and Methods Twenty samples (Silastic Q7–4735) were made with an intrinsic pigmentation. This intrinsic pigmentation was composed of a pink pigment (H-109-P, Factor II) and an opacifier (ZnO). All samples had standardized dimensions (45-mm diameter and 2-mm thickness). Half of the 20 samples manufactured subsequently received an extrinsic pigment (Tan FE–215, Factor II). Therefore, two groups were created (n = 10): Group 1, group with intrinsic pigmentation and without extrinsic pigmentation (control) and Group 2, group with intrinsic and extrinsic pigmentation. Samples were submitted to color and Shore A hardness tests, before and after 1,008 hours of aging. Statistical Analysis Color alteration data were submitted to Student’s t-test (α = 0.05). Shore A hardness data were submitted to two-way analysis of variance and Tukey test (α = 0.05). Results The incorporation of the extrinsic pigment on the silicone did not affect its color (ΔE) when the two groups were compared (p = 0.232). Regarding the hardness test, the interaction between group and period did not interfere with the hardness results(p=0.599). However, the period factor showed that there was a reduction in the hardness of the silicone after aging (p < 0.05). Conclusion In this study, all the hardness and color results of the silicone used were clinically acceptable, regardless of the presence of extrinsic pigmentation.

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Influence of Different Pigmentations and Accelerated Aging on the Hardness and Tear Strength of the A-2186 and MDX4-4210 Silicones

International Journal of Dentistry ◽

10.1155/2020/8492091 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Estefânia Marrega Malavazi ◽

Daniela Micheline dos Santos ◽

Clóvis Lamartine de Moraes Melo Neto ◽

Fernanda Pereira de Caxias ◽

Emily Vivianne Freitas da Silva ◽

...

Keyword(s):

Analysis Of Variance ◽

Repeated Measures ◽

Accelerated Aging ◽

Hardness Test ◽

Strength Test ◽

Tear Strength ◽

Tukey Test ◽

Repeated Measures Analysis ◽

Before And After ◽

Hardness Values

Objective. To evaluate the influence of different pigmentations and accelerated aging on the hardness and tear strength of the A-2186 and MDX4-4210 silicones. Materials and Methods. The samples A-2186 and MDX4-4210 were manufactured without and with pigmentations (black, bronze, and pink). For the Shore A hardness test, 80 samples of each silicone were fabricated, and for the tear strength test, 320 samples of each silicone were fabricated. Eight groups were created for each test (n = 10). These tests were performed before and after 252, 504, and 1008 hours of aging. Three-way repeated-measures analysis of variance and the Tukey test were performed (α = 0.05). Results. The A-2186 silicone showed higher hardness and tear strength when compared with the MDX4-4210 silicone p<0.05, except in the hardness of the A-2186 and MDX4-4210 groups without pigmentation after 1008 hours p>0.05. All hardness values were between 25 and 35 units, regardless of the silicone type, period, and pigmentation (or no pigmentation). In most situations, the hardness of silicones used increased after 252 hours p<0.05. The nonpigmented MDX4-4210 group and all A-2186 groups showed an increase in tear strength after 252 hours p<0.05. For the nonpigmented MDX4-4210 group, from 252 to 1008 hours, there was no change in tear strength p>0.05. All pigmented MDX4-4210 groups showed no change in tear strength from 0 (initial) to 1008 hours of aging p>0.05. In all A-2186 groups, from 252 to 504 hours, there was a reduction in tear strength p<0.05, and from 504 to 1008 hours, there was an increase in tear strength p<0.05, except in the bronze A-2186 group p>0.05. Conclusion. In most situations, the A-2186 silicone showed significantly higher values of hardness and tear strength than the MDX4-4210 silicone. All hardness values were considered clinically acceptable. Accelerated aging could increase, decrease, or not significantly change the hardness and tear strength of the silicones used. The results of hardness and tear strength suggest that MDX4-4210 was more influenced by the presence of pigmentation after aging.

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Color and opacity of composites protected with surface sealants and submitted to artificial accelerated aging

European Journal of Dentistry ◽

10.1055/s-0039-1698927 ◽

2012 ◽

Vol 06 (01) ◽

pp. 024-033 ◽

Cited By ~ 1

Author(s):

Fabiano Gamero Aguilar ◽

Lucas da Fonseca Roberti Garcia ◽

Diogo Rodrigues Cruvinel ◽

Ana Beatriz Silva Sousa ◽

Fernanda de Carvalho Panzeri Pires-de-Souza

Keyword(s):

Accelerated Aging ◽

Color Stability ◽

Scanning Electronic Microscopy ◽

Electronic Microscopy ◽

Surface Protection ◽

Before And After ◽

Color Similarity ◽

Surface Irregularities ◽

Surface Sealants ◽

Color Alteration

ABSTRACTObjectives: To evaluate the color similarity, stability and opacity of composites (TPH, Charisma, and Concept, shade A2) protected with surface sealants (Fortify Plus and Biscover) and cyanoacrylate (Super Bonder).Methods: Forty specimens of each composite were made and separated into 4 groups (n=10) according to the surface protection: GI - without sealant; GII - cyanoacrylate; GIII - Fortify Plus; GIV - Biscover. Color and opacity readings were taken before and after Artificial Acelerated Aging (AAA) and the values obtained for color stability were submitted to statistical analysis by 2-way ANOVA and Bonferroni’s test (P<.05). The values acquired for color similarity were submitted to 1-way ANOVA and Tukey’s test (P<.05). The specimen sufaces were compared before and after AAA using Scanning Electronic Microscopy (SEM).Results: Studied composites did not present the same values for the coordinates L*, a* and b * before AAA, indicating that there was no color similarity among them. All composites presented color alteration after AAA with clinically unacceptable values. Protected groups presented lower opacity variation after AAA, in comparison with the control goup. SEM evaluation demonstrated that AAA increased the surface irregularities in all of the studied groups.Conclusion: Surface sealants were not effective in maintaining composite color, but were able to maintain opacity. (Eur J Dent 2012;6:24-33)

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Assessment of Color Stability of Treated Leathers with Silicone Oil and Polyethylene Glycol

Journal of African Leather and Leather Products Advances ◽

10.15677/jallpa.2014.v1i1.8 ◽

2014 ◽

Vol 1 (1) ◽

pp. 24-34

Author(s):

Alireza K. ◽

Hossein Ahmadi ◽

Mohsen Mohammadi

Keyword(s):

Ascorbic Acid ◽

Polyethylene Glycol ◽

Treatment Process ◽

Color Change ◽

Silicone Oil ◽

Accelerated Aging ◽

Color Stability ◽

Antioxidant Additive ◽

Before And After ◽

Aesthetic Values

Lubricants and leather dressings are the most common treatments of dry and water logged historical leathers. Color change has a great importance during the time and treatment process, due to visual and aesthetic values of historic leather relics. Polyethylene glycol (PEG) and silicone oil (SiO) are frequently used leather dressings in the conservation procedures. Therefore, color stability of treated leathers with PEG and SiO were investigated before and after heat accelerated aging. Moreover, application of ascorbic acid was evaluated as an antioxidant additive for PEG (PEG+AA).Color change after treatment and aging were studied by colorimetry technique in the CIE *L*a*b system. Results indicated to severe color alteration in PEG treated and aged leathers with or without ascorbic acid. Whereas, SiO treated samples showed better stability and minimum color shift after aging. Silicone oil was characterized as the best dressing for historical leathers with compared to PEG and PEG+AA, due to its high stability and aesthetical properties.

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RISKS OF ANEMIA DEVELOPMENT IN DONORS ACCORDING TO INHERITED PREDISPOSITION AND REGULARITY OF BLOOD DONATION

Ulyanovsk Medico-biological Journal ◽

10.34014/2227-1848-2020-1-72-83 ◽

2020 ◽

pp. 72-83

Author(s):

I.M. Vorotnikov ◽

V.A. Razin ◽

I.M. Lamzin ◽

M.N. Sokolova ◽

M.E. Khapman ◽

...

Keyword(s):

Blood Donors ◽

Blood Donation ◽

Hla Antigens ◽

Hla Typing ◽

Main Role ◽

Inherited Predisposition ◽

Group 2 ◽

Student’S T ◽

A Prospective Study ◽

Group 1

Anemia is one of the most common complications of blood donation. Thus, the objective of the paper was to assess the risks of anemia development in donors according to the regularity of donation and inherited predisposition. Materials and Methods. The authors carried out a prospective study, which included 241 blood donors, using random sampling and case-control techniques. Depending on blood donation frequency, the donors were divided into 2 groups: Group 1 consisted of 122 people (51.5 %) frequently donating blood; Group 2 included 119 people (48. 5 %) rarely donating blood. We studied the initial indicators of a general blood test and the same indicators a year after the first blood donation. Additionally, we performed HLA typing of donors. Statistica v. 8.0 software package (Stat Soft Inc., USA) was used for statistical analysis. To compare two independent samples, we used a nonparametric Mann-Whitney U-test and a parametric Student’s t-test (depending on the type of distribution). To assess anemia risks, the odds ratio was calculated. Results. One year after the first blood donation, anemia was diagnosed in 13 people (10.6 %) in Group 1 and in 7 people (5.9 %) in Group 2 (p=0.179). A11 and B7 HLA antigens did not increase anemia risks in group 1 (OS=1.257 (95 % CI 0.318–4.973) and OS=0.240 (95 % CI 0.051–1.134, respectively). HLA-antigens A11 and B7 did not increase anemia risks in Group 1 (OR=1.257 (95 % CI 0.318-4.973) and OR=0.240 (95 % CI 0.051–1.134), respectively). In group 2, antigen-A11 was also an insignificant factor (OS=2.902 (95 % CI 0.606-13.889)) for anemia development. Whereas, antigen-B7 increased anemia risks by 14 times (OS=14.364 (95 % CI 1.644-124.011)). Conclusion. In rare blood donors, it is the genetic factor that plays the main role in anemia development. High prevalence rates of anemia in frequent blood donors are probably determined by other factors. Keywords: anemia, blood donors, HLA typing. Механизмы развития анемий и факторы, их индуцирующие, остаются до конца не изученными. Целью исследования стало изучение риска развития анемии у доноров крови в зависимости от частоты донации и наличия наследственной предрасположенности к развитию анемии. Материалы и методы. Проведено проспективное исследование, выполненное методами случайной выборки и «случай-контроль», в которое вошел 241 донор крови. В зависимости от частоты сдачи доноры были поделены на 2 группы: группу 1 составили 122 чел. (51,5 %), часто сдающие кровь; группу 2 – 119 чел. (48,5 %), редко сдающих кровь. Изучались исходные показатели общего анализа крови и через год от начала донации. Дополнительно проводилось HLA-типирование доноров. Статистический анализ осуществлялся с применением программы Statistica v. 8.0 (Stat Soft Inc., США). Для сравнения двух независимых выборок использовался непараметрический U-критерий Манна–Уитни и параметрический t-критерий Стьюдента (в зависимости от типа распределения). Для оценки риска возникновения анемии рассчитывалось отношение шансов. Результаты. Через год с момента первой сдачи крови в группе 1 выявлено 13 чел. (10,6 %) с анемией, в группе 2 – 7 чел. (5,9 %) (р=0,179). Наличие HLA-антигенов А11 и B7 не повышало риск развития анемии в группе 1 (ОШ=1,257 (95 % ДИ 0,318–4,973) и ОШ=0,240 (95 % ДИ 0,051–1,134 соответственно). В группе 2 наличие гена А11 также являлось незначимым фактором (ОШ=2,902 (95 % ДИ 0,606–13,889), присутствие гена В7 в 14 раз повышало риск развития анемии (ОШ=14,364 (95 % ДИ 1,664–124,011). Выводы. Высокий риск развития анемии у редко сдающих кровь доноров обусловливается генетическими факторами. Высокая распространённость анемии у часто сдающих кровь доноров, вероятно, определяется другими факторами. Ключевые слова: анемия, доноры крови, HLA-типирование.

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Comparison of 24-Hour Electrocardiogram Parameters in Patients with Graves Disease Before and After Anti-Thyroid Therapy

Endocrine Metabolic & Immune Disorders - Drug Targets ◽

10.2174/1871530320666200729145100 ◽

2020 ◽

Vol 20 ◽

Author(s):

Gamze Akkuş ◽

Yeliz Sökmen ◽

Mehmet Yılmaz ◽

Özkan Bekler ◽

Oğuz Akkuş

Keyword(s):

Treatment Group ◽

Medical Treatment ◽

Surgical Therapy ◽

Graves Disease ◽

Before And After ◽

Euthyroid Status ◽

Ectopic Beats ◽

Group 2 ◽

Electrocardiographic Parameters ◽

Group 1

Background: We aimed prospectively investigate the laboratory and electrocardiographic parameters (hearth rate, QRS, QT, QTc, Tpe, Tpe/QTc, arrhythmia prevalance) in patients with graves disease before and after antithyroid therapy. Methods: 71 patients (48 female, 23 male), age between 18-50 (mean±SD: 36.48±12.20 ) with GD were included into the study. Patients treated with antithyroid therapy (thionamids and/or surgical therapy) to maintain euthyroid status. Patients were examined in terms of electrocardiographic parameters before and after the treatment. Results: Mean TSH, free thyroxin (fT4) and tri-iodothyrionine (fT3) levels of all patients were 0.005±0.21, 3.27± 1.81, 11.42±7.44, respectively. While 9 patients (group 2) underwent surgical therapy, had suspicious of malignant nodule or large goiter and unresponsiveness to medical treatment; the other patients (n=62, group 1) were treated with medical therapy. Patients with surgical therapy had more increased serum fT4 (p=0.045), anti-thyroglobulin value (p=0.018) and more severe graves orbitopathy (n=0.051) before treatment when compared to medical therapy group. Baseline Tpe duration and baseline Tpe/QTc ratio and frequency of supraventricular ectopic beats were found to be significantly higher in group 2 when compared to group 1 (p=0.00, p=0.005). Otherwise baseline mean heart rate, QRS duration, QTc values of both groups were similar. Although the patients became their euthyroid status, group 2 patients had still suffered from more sustained supraventricular ectopics beats than group 1. Conclusion: Distinct from medical treatment group, surgical treatment group with euthyroidism at least 3 months had still suffered from an arrhythmia (Tpe, Tpe/QTc, supraventricular and ventricular ectopic beats).

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A Randomized, Controlled, Parallel-Group, Trial on the Effects of Melatonin on Fatigue Associated with Breast Cancer and Its Adjuvant Treatments

Integrative Cancer Therapies ◽

10.1177/1534735420988343 ◽

2021 ◽

Vol 20 ◽

pp. 153473542098834

Author(s):

Abdolazim Sedighi Pashaki ◽

Kamal Mohammadian ◽

Saeid Afshar ◽

Mohammad Hadi Gholami ◽

Abbas Moradi ◽

...

Keyword(s):

Breast Cancer ◽

Adjuvant Chemotherapy ◽

Intervention Group ◽

Chi Square ◽

Significance Level ◽

Severe Fatigue ◽

Before And After ◽

Brief Fatigue Inventory ◽

Chi Square Test ◽

Student’S T

Objective: Fatigue associated with malignant conditions and their treatments is a disabling condition. This trial assessed the anti-fatigue effects of melatonin coadministration during adjuvant treatment of patients with the breast cancer. Material and Methods: Patients with breast cancer were randomly assigned to receive melatonin or placebo during adjuvant chemotherapy and radiotherapy. Thirty-seven patients were randomly enrolled in each group. The mean ages of patients in the intervention and control groups were 50.47 ± 10.79 and 46.05 ± 10.55 years, respectively ( P = .223). The intervention group received oral melatonin (18 mg/day) from 1 week before until 1 month after the adjuvant radiotherapy. The level of fatigue was assessed before and after intervention using Brief Fatigue Inventory (BFI) in both groups. To analyze data, the Student’s t-test and the Chi-square test were used at a significance level of P ≤ .05. Results: The BFI score was similar before the intervention in both groups, however, after the intervention, it was significantly lower in the melatonin group ( P < .001). Moreover, the frequency of severe fatigue in the melatonin group was significantly lower than in the placebo group after intervention (42.1% vs 83.3%, P < .001). Conclusion: Coadministration of melatonin during adjuvant chemotherapy and radiotherapy of women with breast cancer decreased the levels of fatigue associated with the malignant condition and its treatments.

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Student Pharmacists Self-Perceived Confidence in Communication Skills With Healthcare Practitioners Before and After a Seminar Course

Journal of Pharmacy Practice ◽

10.1177/08971900211018430 ◽

2021 ◽

pp. 089719002110184

Author(s):

Kimberly L. Barefield ◽

Caroline Champion ◽

Lucy Yang ◽

Brent Rollins

Keyword(s):

Survey Design ◽

Research Question ◽

Pharmacy Practice ◽

Course Evaluation ◽

Internship Experience ◽

Before And After ◽

Student’S T ◽

Strongly Agree ◽

Pharmacy Curriculum ◽

Question Survey

Introduction: Competent pharmacy practice requires the ability to critically evaluate the medical literature and communicate pharmacotherapy information and recommendations to healthcare practitioners. Given the limited research on how these skills are taught, a seminar course in the third year of the pharmacy curriculum was designed to strengthen these skills and abilities. Methods: This was a prospective, pre- and post-cohort survey design. Students were informed of the study’s intent with participation being voluntary and not affecting their course grade. Students received the same survey at the beginning and end of the semester. The 20-question survey assessed self-perceived confidence in the domains of communication and literature evaluation using a 5-point, Likert-type Strongly Disagree-Strongly Agree Scale. Demographic information and students’ previous pharmacy work and internship experience were collected as a part of the survey. Descriptive statistics and Student’s t-test were used to assess the research question and comparisons of student demographics. Results: Sixty-eight of a possible 91 students (75% response rate) completed both the pre- and post-survey. There was no statistically significant differences between any of the measured demographics. Overall, students slightly agreed they were confident in their communication and literature evaluation skills in the pre-course evaluation, with communicating drug interactions as the least confident area. Post-course, students were significantly more confident in all but 5 of 20 measured areas. Conclusion: The Seminar course resulted in a positive change in students’ perception of confidence to communicate with healthcare professionals and ability to evaluate drug literature.

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Three-dimensional analysis of the root canal preparation with Reciproc Blue®, WaveOne Gold® and XP EndoShaper®: a new method in vivo

BMC Oral Health ◽

10.1186/s12903-021-01450-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Javier Caviedes-Bucheli ◽

Nestor Rios-Osorio ◽

Diana Usme ◽

Cristian Jimenez ◽

Adriana Pinzon ◽

...

Keyword(s):

3D Reconstruction ◽

Root Canal ◽

Paired Comparison ◽

Three Dimensional ◽

New Method ◽

Root Canal Preparation ◽

Paired Data ◽

Before And After ◽

Student’S T

Abstract Background The purpose of this study was to evaluate the changes in canal volume after root canal preparation in vivo with 3 different single-file techniques (Reciproc-Blue®, WaveOne-Gold® and XP-EndoShaper®), with a new method using CBCT and 3D reconstruction. Methods In this prospective study, thirty human lower premolars from healthy patients were used, in which extraction was indicated for orthodontic reasons. All the teeth used were caries- and restoration-free with complete root development, without signs of periodontal disease or traumatic occlusion, and with only one straight canal (up to 25º curvature). Teeth were randomly divided into three different groups: Reciproc-Blue, WaveOne-Gold and XP-EndoShaper. CBCT scans before root canal preparation were used to create a 3D reconstruction with RHINOCEROS 5.0 software to assess the initial canal volume, and then compared with 3D reconstructions after canal preparation to measure the increase in canal volume. Student’s t test for paired data were used to determine statistically significant differences between the before and after canal volumes. Anova test was used to determine statistically significant differences in the percentage of canal volume increase between the groups and Tukey's post-hoc test were used to paired comparison. Results Reciproc-Blue showed the higher increase in canal volume, followed by WaveOne-Gold and XP-EndoShaper (p = 0.003). XP-EndoShaper did not show a statistically significant increase in canal volume after root canal preparation (p = 0.06). Conclusion With this model, Reciproc-Blue showed higher increase in root canal volume, followed by WaveOne-Gold, while XP-EndoShaper did not significantly increase root canal volume during preparation.

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Biomechanical properties of the bone during implant placement

BMC Oral Health ◽

10.1186/s12903-021-01442-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Ádám László Nagy ◽

Zsolt Tóth ◽

Tamás Tarjányi ◽

Nándor Tamás Práger ◽

Zoltán Lajos Baráth

Keyword(s):

Bone Structure ◽

Biomechanical Properties ◽

Control Group ◽

Dynamic Tests ◽

Bone Model ◽

Implant Placement ◽

Significant Difference ◽

Before And After ◽

Group 2 ◽

Post Hoc

Abstract Background In this research the biomechanical properties of a bone model was examined. Porcine ribs are used as experimental model. The objective of this research was to investigate and compare the biomechanical properties of the bone model before and after implant placement. Methods The bone samples were divided in three groups, Group 1 where ALL-ON-FOUR protocol was used during pre-drilling and placing the implants, Group 2 where ALL-ON-FOUR protocol was used during pre-drilling, and implants were not placed, and Group 3 consisting of intact bones served as a control group. Static and dynamic loading was applied for examining the model samples. Kruskal–Wallis statistical test and as a post-hoc test Mann–Whitney U test was performed to analyze experimental results. Results According to the results of the static loading, there was no significant difference between the implanted and original ribs, however, the toughness values of the bones decreased largely on account of predrilling the bones. The analysis of dynamic fatigue measurements by Kruskal–Wallis test showed significant differences between the intact and predrilled bones. Conclusion The pre-drilled bone was much weaker in both static and dynamic tests than the natural or implanted specimens. According to the results of the dynamic tests and after a certain loading cycle the implanted samples behaved the same way as the control samples, which suggests that implantation have stabilized the skeletal bone structure.

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The Effect of Broccoli Sprout Extract on Seasonal Grass Pollen-Induced Allergic Rhinitis

Nutrients ◽

10.3390/nu13041337 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1337

Author(s):

Joseph Yusin ◽

Vivian Wang ◽

Susanne M. Henning ◽

Jieping Yang ◽

Chi-Hong Tseng ◽

...

Keyword(s):

Allergic Rhinitis ◽

Nasal Spray ◽

Placebo Tablet ◽

Group 4 ◽

Cytokine Levels ◽

Before And After ◽

Group 3 ◽

Nasal Steroid ◽

Group 2 ◽

Broccoli Sprout

Patients exposed to pollutants are more likely to suffer from allergic rhinitis and may benefit from antioxidant treatment. Our study determined if patients diagnosed with grass-induced allergic rhinitis could benefit from broccoli sprout extract (BSE) supplementation. In total, 47 patients were confirmed with grass-induced allergic rhinitis and randomized to one of four groups: group 1 (nasal steroid spray + BSE), group 2 (nasal steroid spray + placebo tablet), group 3 (saline nasal spray + BSE) and group 4 (saline nasal spray + placebo tablet). Peak Nasal Inspiratory Flow (PNIF), Total Nasal Symptoms Scores (TNSS) and nasal mucus cytokine levels were analyzed in samples collected before and after the 3-week intervention. Comparing before and after the intervention, PNIF improved significantly when comparing Groups 1 and 2, vs. placebo, at various time points (p ≤ 0.05 at 5, 15, 60 and 240 min) following nasal challenge, while TNSS was only statistically significant at 5 (p = 0.03), 15 (p = 0.057) and 30 (p = 0.05) minutes. There were no statistically significant differences in various cytokine markers before and after the intervention. Combining nasal corticosteroid with BSE led to the most significant improvement in objective measures.

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