scholarly journals Force decay and dimensional changes of thermoplastic and novel thermoset elastomeric ligatures

2016 ◽  
Vol 86 (5) ◽  
pp. 818-825 ◽  
Author(s):  
Ahmed I. Masoud ◽  
Milena Bulic ◽  
Grace Viana ◽  
Ana K. Bedran-Russo
Keyword(s):  
Force Measurement ◽  
Rocky Mountain ◽  
Outer Diameter ◽  
Dimensional Changes ◽  
Time Points ◽  
Percent Change ◽  
Force Decay ◽  
Custom Made ◽  
The Difference ◽  
Student’S T

ABSTRACT Objectives:  To compare over a period of 8 weeks (1) the force decay and (2) the dimensional changes between thermoplastic (TP) and thermoset (TS) elastomeric ligatures. Materials and Methods:  TP and TS elastomeric ligatures were obtained from Rocky Mountain Orthodontics™. The TS ligatures were custom made specifically for this study. The sample included 72 clear TP and 72 clear TS elastomeric ligatures. The experiment was performed in a simulated oral environment (pH of 6.75) at 37°C. The remaining forces and the dimensional changes were measured at different time points over a period of 8 weeks. Results:  Student’s t-tests revealed significant differences in percent force loss, percent change in outer diameter, percent change in inner diameter, and percent change in wall thickness between TP and TS elastomeric ligatures across all time points (P < .001). The difference in percent change in width between TP and TS elastomeric ligatures was not significant at all time points (P > .05). The mean difference in force loss between TP and TS across all time points was 22.91%. The TP and TS specimens exhibited 93.04% and 77.41% force loss, respectively, at the 28th day. Conclusions:  This novel TS elastomeric ligature showed significantly less force decay and dimensional changes over time; therefore, it might be superior during initial leveling and aligning and during finishing stages. Using a transfer jig to prevent relaxation of the specimens before force measurement showed that force decay of commercially available elastomeric ligatures was greater than that described in previous publications.

scholarly journals Effect of Bleaching Mouthwash on Force Decay of Orthodontic Elastomeric Chains

2018 ◽  
Vol 19 (2) ◽  
pp. 221-225 ◽  
Author(s):  
Mohammad Behnaz ◽  
Fatemeh Namvar ◽  
Setareh Sohrabi ◽  
Mina Parishanian
Keyword(s):  
Sodium Fluoride ◽  
Artificial Saliva ◽  
Test Group ◽  
Clinical Problem ◽  
Control Group ◽  
Force Decay ◽  
Custom Made ◽  
The Difference ◽  
Elastomeric Chains

ABSTRACT Introduction Force decay elastomeric chains are significant, and it is a clinical problem. Aim The aim of this study was to evaluate the effects of bleaching agent in the mouthwash on the force decay of orthodontic chains. Materials and methods In this experimental study, 160 gray closed elastomeric chains were randomly divided into three groups (one control and two test groups). Four loops of chains were stretched for 25 mm on custom-made jig. Control group specimens were immersed in artificial saliva during the test period. Test group specimens were immersed twice a day for 30 seconds in the whitening (LISTERINE® HEALTHY WHITE™) and daily sodium fluoride (LISTERINE® TOTAL CARE ZERO) mouthwashes. All specimens were immersed in artificial saliva at 37°C. Force was measured at different time points (initial, 1, 7, 14, 21, 28 days). Statistical analysis was performed by two-way analysis of variance (ANOVA) and Bonferroni methods (α = 0.05). Results Force of elastomeric chains was decreased dramatically in all groups during the experiment. After 24 hours, force was decreased by 42.18, 48.34, and 53.38% in control group, daily, and bleaching mouthwash groups respectively. The corresponding numbers after 4 weeks were 66.30, 76.73, and 86.48. The difference between three groups at days 1 and 28 was statistically significant (p < 0.05). Conclusion Within the limitations of the current in vitro study, bleaching and sodium fluoride mouthwashes could cause force decay of orthodontic elastomeric chains. Whitening mouthwash is more weakening for elastomeric chains. Clinical significance Use of whitening mouthwash by orthodontic patients could decrease the force of elastomeric chains, so it could be recommended to use them for a short time. How to cite this article Behnaz M, Namvar F, Sohrabi S, Parishanian M. Effect of Bleaching Mouthwash on Force Decay of Orthodontic Elastomeric Chains. J Contemp Dent Pract 2018;19(2):221-225.

Meniscal Deficiency Period and High Body Mass Index Are Preoperative Risk Factors for Joint Space Narrowing After Meniscal Allograft Transplantation

2021 ◽  
Vol 49 (3) ◽  
pp. 693-699
Author(s):  
Sang-Min Lee ◽  
Seong-Il Bin ◽  
Jong-Min Kim ◽  
Bum-Sik Lee ◽  
Kuen Tak Suh ◽  
...  
Keyword(s):  
Risk Factors ◽  
Femoral Condyle ◽  
Joint Space ◽  
Preoperative Risk ◽  
Meniscal Allograft Transplantation ◽  
Time Points ◽  
Allograft Transplantation ◽  
Preoperative Risk Factors ◽  
Meniscal Allograft ◽  
The Difference

Background: Several studies have reported further reduction in joint space width (JSW) after meniscal allograft transplantation; some contributing postoperative factors are known, although preoperative factors remain unclear. This study is the first to analyze the preoperative risk factors for reduced JSW in patients after lateral meniscal allograft transplantation (LMAT). Hypothesis: Poor cartilage status and high preoperative body mass index (BMI) influence the postoperative progression of joint space narrowing. Study Design: Case-control study; Level of evidence, 3. Methods: We retrospectively studied 79 patients after LMAT who were observed for at least 5 years. JSWs on weightbearing flexion posteroanterior radiographs were measured preoperatively and at the 5-year mark. Differences in JSW were divided into more progression and less progression groups. The modified Outerbridge cartilage grades based on magnetic resonance imaging assessments were compared at subtotal/total meniscectomy and at LMAT to determine the difference between time points. Preoperative between-group differences in sex, age, surgical side, follow-up period, weight, height, BMI, and meniscal deficiency period were analyzed. Clinical outcomes were evaluated using the Lysholm score. Data were examined using univariate and multivariate logistic regressions. Results: Radiographically, the overall change in JSW from preoperative to follow-up was 0.58 mm (range, –0.23 to 1.83 mm). Reductions in JSW in the more progression and less progression groups were 0.94 ± 0.32 and 0.22 ± 0.21 mm (mean ± SD), respectively. There was no difference in cartilage status between the groups at meniscectomy or LMAT; however, changes between time points were significant on the lateral femoral condyle and lateral tibial plateau. Clinically, there were significant differences in weight, BMI, and meniscal deficiency period between the 2 groups. Postoperative Lysholm scores increased as compared with the preoperative scores, but there was no difference among the postoperative time points. In the univariate logistic regression risk analysis, weight, BMI, meniscal deficiency period, and the difference in cartilage status between time points for the lateral femoral condyle and lateral tibial plateau were identified as significant. In the subsequent multivariate logistic regression, BMI (odds ratio, 1.45; P = .016) and meniscal deficiency period (odds ratio, 1.21; P = .037) were the statistically significant factors. Conclusion: BMI and meniscal deficiency period were preoperative risk factors for JSW narrowing after LMAT. This suggests that the meniscal deficiency period from meniscectomy to LMAT may be shortened and that proper weight management can lead to successful LMAT.

scholarly journals 152. Applying A Difference-in-Difference Analysis to Assess Effect of Antimicrobial Stewardship Strategies on Changes in Antimicrobial Use

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S86-S86
Author(s):  
Ann F Chou ◽  
Yue Zhang ◽  
Makoto M Jones ◽  
Christopher J Graber ◽  
Matthew B Goetz ◽  
...  
Keyword(s):  
Antimicrobial Stewardship ◽  
Clinical Pharmacist ◽  
Antibiotic Use ◽  
Feedback Mechanism ◽  
Health Care Facilities ◽  
Antimicrobial Use ◽  
Time Points ◽  
The Difference ◽  
The Impact ◽  
Over Time

Abstract Background About 30–50% of inpatient antimicrobial therapy is sub-optimal. Health care facilities have utilized various antimicrobial stewardship (AS) strategies to optimize appropriate antimicrobial use, improve health outcomes, and promote patient safety. However, little evidence exists to assess relationships between AS strategies and antimicrobial use. This study examined the impact of changes in AS strategies on antimicrobial use over time. Methods This study used data from the Veterans Affairs (VA) Healthcare Analysis & Informatics Group (HAIG) AS survey, administered at 130 VA facilities in 2012 and 2015, and antimicrobial utilization from VA Corporate Data Warehouse. Four AS strategies were examined: having an AS team, feedback mechanism on antimicrobial use, infectious diseases (ID) attending physicians, and clinical pharmacist on wards. Change in AS strategies were computed by taking the difference in the presence of a given strategy in a facility between 2012–2015. The outcome was the difference between antimicrobial use per 1000 patient days in 2012–2013 and 2015–2016. Employing multiple regression analysis, changes in antimicrobial use was estimated as a function of changes in AS strategies, controlling for ID human resources in and organizational complexity. Results Of the 4 strategies, only change in availability of AS teams had an impact on antimicrobial use. Compared to facilities with no AS teams at both time points, antibiotic use decreased by 63.9 uses per 1000 patient days in facilities that did not have a AS team in 2012 but implemented one in 2015 (p=0.0183). Facilities that had an AS team at both time points decreased use by 62.2 per 1000 patient days (p=0.0324). Conclusion The findings showed that AS teams reduced inpatient antibiotic use over time. While changes in having feedback on antimicrobial use and clinical pharmacist on wards showed reduced antimicrobial use between 2012–2015, the differences were not statistically significant. These strategies may already be a part of a comprehensive AS program and employed by AS teams. In further development of stewardship programs within healthcare organizations, the association between AS teams and antibiotic use should inform program design and implementation. Disclosures All Authors: No reported disclosures

The Impact of Domestic Violence on Women’s Self-Attitude in Kazakhstan

2020 ◽  
pp. 77-83
Author(s):  
Zhanna Kalmatayeva
Keyword(s):  
Domestic Violence ◽  
Quantitative Research ◽  
Self Esteem ◽  
Self Report ◽  
Control Group ◽  
Personality Research ◽  
Attitude Test ◽  
The Difference ◽  
Student’S T ◽  
The Impact

The purpose of the article was to study the problems of domestic violence of women and its consequences in Kazakhstan. The analysis of the results of the study of self-attitude and self-esteem of women subjected to domestic violence. Revealed there is a correlation between the level of self-attitude of domestic violence victims and the non-differentiated I-concept. 140 women participated in the present study, 70 women are control group which not subjected to domestic violence and 70 women of them who have currently reported domestic violence in the Crisis Center "Umit" in Nur-Sultan in the period from November 2017 to October 2019. Quantitative research method was used in terms of survey model by implementing a psychological test “The self-attitude test questionnaire (SA)” that assesses self-relation, differentiated by self-esteem, self-sympathy, self-interest, and expectations of self-reliance of participants. Also, during the study was used personal questionnaire “Who am I?” a variant of non-standardized self-report, approaching the projective methods of personality research. Descriptive statistics were used to analyze the answers in terms of their levels of the participants’ self-esteem and self-relation and further, since it was revealed according to the results reflect the difference in the two groups by the values obtained from these scales, the Student's t-test for independent groups was used [2] was used to reveal whether there is any correlation between the components of the scale. The obtained results can be used to interventions and training of family for counselors in order to promote women's self-esteem and self-relation.

scholarly journals Level of headaches after surgical aneurysm clipping decreases significantly faster compared to endovascular coiled patients

2017 ◽  
Vol 7 (2) ◽  
Author(s):  
Athanasios K. Petridis ◽  
Jan F. Cornelius ◽  
Marcel A. Kamp ◽  
Sina Falahati ◽  
Igor Fischer ◽  
...  
Keyword(s):  
Aneurysm Rupture ◽  
Endovascular Coiling ◽  
Analog Scale ◽  
Surgical Clipping ◽  
Time Points ◽  
Ruptured Aneurysms ◽  
Aneurysm Clipping ◽  
Incidental Aneurysms ◽  
The Difference ◽  
Late Recovery

In incidental aneurysms, endovascular treatment can lead to post-procedural headaches. We studied the difference of surgical <em>clipping</em> <em>vs</em>. endovascular <em>coiling</em> in concern to post-procedural headaches in patients with ruptured aneurysms. Sixtyseven patients with aneurysmal subarachnoidal haemorrhage were treated in our department from September 1<sup>st</sup> 2015 - September 1<sup>st</sup> 2016. 43 Patients were included in the study and the rest was excluded because of late recovery or highgrade subarachnoid bleedings. Twenty-two were surgical treated and twenty-one were interventionally treated. We compared the post-procedural headaches at the time points of 24 h, 21 days, and 3 months after treatment using the visual analog scale (VAS) for pain. After surgical clipping the headache score decreased for 8.8 points in the VAS, whereas the endovascular treated population showed a decrease of headaches of 3.3 points. This difference was highly statistical significant and remained significant even after 3 weeks where the pain score for the surgically treated patients was 0.68 and for the endovascular treated 1.8. After 3 months the pain was less than 1 for both groups with surgically treated patients scoring 0.1 and endovascular treated patients 0.9 (not significant). Clipping is relieving the headaches of patients with aneurysm rupture faster and more effective than endovascular coiling. This effect stays significant for at least 3 weeks and plays a crucial role in stress relieve during the acute and subacute ICU care of such patients.

scholarly journals Numerical tools to estimate the flux of a gas across the air–water interface and assess the heterogeneity of its forcing functions

Ocean Science ◽  
2013 ◽  
Vol 9 (2) ◽  
pp. 355-375 ◽  
Author(s):  
V. M. N. C. S. Vieira ◽  
F. Martins ◽  
J. Silva ◽  
R. Santos
Keyword(s):  
Atmospheric Stability ◽  
Water Interface ◽  
Co2 Fluxes ◽  
Gas Flux ◽  
Ria Formosa ◽  
Custom Made ◽  
Air Water Interface ◽  
Forcing Functions ◽  
Flux Model ◽  
The Difference

Abstract. A numerical tool was developed for the estimation of gas fluxes across the air–water interface. The primary objective is to use it to estimate CO2 fluxes. Nevertheless application to other gases is easily accomplished by changing the values of the parameters related to the physical properties of the gases. A user-friendly software was developed allowing to build upon a standard kernel a custom-made gas flux model with the preferred parameterizations. These include single or double layer models; several numerical schemes for the effects of wind in the air-side and water-side transfer velocities; the effects of atmospheric stability, surface roughness and turbulence from current drag with the bottom; and the effects on solubility of water temperature, salinity, air temperature and pressure. An analysis was also developed which decomposes the difference between the fluxes in a reference situation and in alternative situations into its several forcing functions. This analysis relies on the Taylor expansion of the gas flux model, requiring the numerical estimation of partial derivatives by a multivariate version of the collocation polynomial. Both the flux model and the difference decomposition analysis were tested with data taken from surveys done in the lagoon system of Ria Formosa, south Portugal, in which the CO2 fluxes were estimated using the infrared gas analyzer (IRGA) and floating chamber method, whereas the CO2 concentrations were estimated using the IRGA and degasification chamber. Observations and estimations show a remarkable fit.

scholarly journals Evaluation of the effectiveness of self-massage in dysmenorrhea/ Ocena efektywności automasażu w redukcji bólu menstruacyjnego kobiet

2017 ◽  
Vol 11 (3) ◽  
pp. 26-32
Author(s):  
Anna Dobrzycka ◽  
Iwona Wilk
Keyword(s):  
Muscle Tension ◽  
Pain Scale ◽  
Quality Of Sleep ◽  
Menstrual Pain ◽  
Before And After ◽  
Average Pain ◽  
The Difference ◽  
Student’S T ◽  
Experimental Group

Background: Primary menstrual pain affects approximately 45-95% of women between 20-25 years of age. A non-invasive method in reducing menstrual pain by relaxing muscle tension is a massage. It brings the structural tension to normal levels and restores correct blood flow in the pelvic region. Aim of the study: The aim of this study was to test the usefulness of a self-massage in reducing the primary menstrual pain. Materials and methods: Out of 180 female students, 34 women aged 19-30 were qualified for the study with the use of a survey. Pittsburgh Sleep Quality Index questionnaire and visual analog pain scale (VAS) were used for the assessment before and after the therapy. Women in the experimental group performed tensegrity selfmassage a few days before the onset of bleeding for two menstrual cycles. Results were analyzed using Student’s t test and one-way analysis of variance (ANOVA). Results: Applying the self-massage statistically proved to significantly reduce the perception of pain (p=0.001) and the number of days with pain (p=0.007) in the experimental group. Within this group, the difference was noted in all participants except one. In addition, a third measurement was taken in order to assess the duration of the effect. The result of the average pain and number of days of pain after the extension was higher than in the second evaluation, but significantly lower than before the experiment. The significance was in accordance with the evaluation of pain, p=0.002 and number of days p=0.03. Evaluation of the quality of sleep in the experimental group was significantly better (p = 0.04) than before treatment. Conclusions: Self-massage reduces primary menstrual pain in women and can be used as an assisted form of self-therapy. It improves the quality of sleep.

Foot Macrodactyly Associated with Klippel-Trenaunay Syndrome

2021 ◽  
Vol 23 (5) ◽  
pp. 375-380
Author(s):  
Maurizio De Pellegrin ◽  
Désirée Moharamzadeh ◽  
Giacomo Placella ◽  
Vincenzo Salini
Keyword(s):  
Functional Outcome ◽  
Congenital Malformation ◽  
Patient’S Satisfaction ◽  
Length Difference ◽  
Custom Made ◽  
The Difference ◽  
The Right ◽  
Klippel Trenaunay Syndrome

Klippel-Trenaunay syndrome is a rare congenital malformation which may be associated with macrodactyly. The main problem is the need for custom-made shoes. We describe the case of a female newborn affected by Klippel-Trenaunay syndrome, with a larger and longer right foot; the difference increased progressively and, at 5 years of age, the right foot was 50% larger and 38% longer than the left one. Due to the progression of the deformity, reduction surgery was advised to reduce the foot’s width. Resection of the second ray and 2nd cuneiform was performed. The result was excellent and there were no complications during a 10-year follow-up period with a decrease of width and length difference to 10% and 4%, respectively, in comparison to the contralateral foot. There were no gait anomalies. Abnormal foot width and length represented the main problems and guided the surgical strategy. Second ray resection was effective, without complications and with a good long-term functional outcome. Possibility of wearing fashionable conventional shoes without insoles was achieved to the patient’s satisfaction

Analysis of Stress Distribution for Powder Compression Molding by Finite Element Method

2019 ◽  
Vol 891 ◽  
pp. 269-274 ◽  
Author(s):  
Prakorb Chartpuk ◽  
Chaiwat Chaimahapuk
Keyword(s):  
Stress Distribution ◽  
Natural Frequency ◽  
Ceramic Powder ◽  
Bearing Steel ◽  
Outer Diameter ◽  
Maximum Compression ◽  
Aisi 52100 ◽  
Steel Aisi ◽  
The Difference ◽  
Powder Compression

The ultrasonic mold was designed for the ceramic powder compression. CAD and CAE were used in the design to analyze the mold strength and its natural frequency. The study of stress distribution and compression in upper and lower punch, mold body and waveguide comparison of stresses was analyzed by FEA experiments under maximum compression at 50,000 N to validate the results of both methods and the mold natural frequency. The difference between FEA and experimental analysis was 3-7%, acceptable. The redesign results in a cylindrical mold body with the outer diameter of 80 mm, the height of 100 mm, and the upper punch of 125 mm in length. The six sides are 26 mm of the high waveguide with 100 mm height. The internal and external diameters are 80 and 110 mm, respectively. The mold has been redesigned and can support the maximum compression force of 1,500 kN. with the bearing steel, AISI 52100, obtainable hardness 65 HRC, the stress concentration occurs at the neck of the upper punch using the ultrasonic at 12.00 to 12.45 kHz.

Sign in / Sign up

Export Citation Format

Share Document