scholarly journals Effect of Microimplant Neck Design with and without Microthread on Pullout Strength and Destruction Volume

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5991
Author(s):  
Yu-Chuan Tseng ◽  
Han-Sheng Chen ◽  
Szu-Yu Hsiao ◽  
Kun-Jung Hsu ◽  
Chun-Ming Chen

The microthread neck concept has been applied to dental implants. This study investigated the pullout strength and destruction volume of orthodontic microimplants with and without the microthread neck design. Fifteen microimplants (diameter: 1.5 × 10 mm) of three types (Types A and B: without microimplant neck; Type C: with microimplant neck) were tested. The insertion torque (IT), Periotest value (PTV), horizontal pullout strength (HPS), and horizontal destruction volume (HDV) of each type were measured. Kruskal–Wallis H test and Dunn’s post-hoc comparison test were performed to compare the measured values of the three types of microimplants. The correlations of the measured values were used to perform the Spearman’s correlation coefficient analysis. The ITs of Types B (8.8 Ncm) and C (8.9 Ncm) were significantly higher than those of Type A (5.2 Ncm). Type B yielded the lowest PTV (4.1), and no statistical differences in PTV were observed among the three types. Type A had a significantly lower HPS (158.8 Ncm) than Types B (226.9 Ncm) and C (212.8 Ncm). The three types did not exhibit any significant differences in the HDV. The results of the Spearman’s correlation coefficient test revealed that HDV (ρ = 0.710) and IT (ρ = 0.813) were strongly correlated with HPS, whereas for PTV and HPS, it was not. HPS was strongly and significantly correlated with HDV. The orthodontic microimplant with a microimplant neck design did not perform better than that without a microthread in the mechanical strength test.

2021 ◽  
Author(s):  
Changsheng Chen ◽  
Aimin Ji ◽  
Zhonghang Zhao ◽  
Lingjie Fu

Abstract Background: Self-tapping bone screws hard to insert will brings many surgical risks such as damage the bone, screw failure. This study investigated the effect of different cutting flute offset and different surface treatment on the insertion torque and pullout strength for self-tapping bone screws.Methods: Titanium alloy screws with five types cutting flute offset and two types surface treatment, were tested for maximum insertion torque and pullout strength in a simulation cortical bone material. One group of each type surface treatment screws were tested for torsional properties. All tests were principally performed according to bone screws test standard. Results: For two types surface treatment, the insertion torque of design with 0.4mm offset was less than others cutting flute offset (p<0.05), and the pullout strength of design with 0.2mm offset was bigger than others group (p<0.05). Compared two surface treatment, the insertion torque of dark anodized screws was less than bead blasted, and the former pullout strength was bigger than the latter screws with the offset from 0mm to 0.4mm(p<0.05).Conclusions: The study results show that different cutting flute offset design and surface treatment effect on the insertion torque, and the bigger cutting flute offset has the lower inserting resistance, and the comprehensive performance of dark anodized screws were better than bead blasted.


2019 ◽  
Vol 9 (8) ◽  
pp. 1525 ◽  
Author(s):  
Shen ◽  
Kim ◽  
Kang ◽  
Yeom

Although dual-threaded pedicle screws have been developed, the advantages over single-threaded screws remain controversial. We aimed to investigate the biomechanical performance of two types of dual-threaded pedicle screw by comparing their pullout strength with that of a single-threaded screw in relation to bone quality. Four types of pedicle screw with different thread patterns were designed. Type I: single-threaded screw; Type II: double-threaded screw; Type III: dual-threaded screw; Type IV: a newly designed double dual-threaded screw. Five types of polyurethane foams simulating various degrees of bone quality were used. These were: Type A: cancellous bone; Type B: cancellous bone with cortical bone in the upper margin; Type C: osteoporotic cancellous bone; Type D: osteoporotic cancellous bone with cortical bone in the upper margin; and Type E: osteoporotic bone with cortical bone in the upper and lower margins. A comparison of the pullout strength of Type I, II, and III screws in Type A, B, C and D bone specimens was performed. Type C and E bone specimens were used for comparisons among Type I, II, and IV screws. Compared to the single-threaded screw, the dual-threaded pedicle screws exhibited higher pullout strength in normal-quality bone and significantly lower pullout strength in compromised osteoporotic bone. However, the double dual-threaded screw exhibited better pullout biomechanics in osteoporotic bone with bi-cortical bone.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1163
Author(s):  
Suzana Shahar ◽  
Mohd Razif Shahril ◽  
Noraidatulakma Abdullah ◽  
Boekhtiar Borhanuddin ◽  
Mohd Arman Kamaruddin ◽  
...  

Measuring dietary intakes in a multi-ethnic and multicultural setting, such as Malaysia, remains a challenge due to its diversity. This study aims to develop and evaluate the relative validity of an interviewer-administered food frequency questionnaire (FFQ) in assessing the habitual dietary exposure of The Malaysian Cohort (TMC) participants. We developed a nutrient database (with 203 items) based on various food consumption tables, and 803 participants were involved in this study. The output of the FFQ was then validated against three-day 24-h dietary recalls (n = 64). We assessed the relative validity and its agreement using various methods, such as Spearman’s correlation, weighed Kappa, intraclass correlation coefficient (ICC), and Bland–Altman analysis. Spearman’s correlation coefficient ranged from 0.24 (vitamin C) to 0.46 (carbohydrate), and almost all nutrients had correlation coefficients above 0.3, except for vitamin C and sodium. Intraclass correlation coefficients ranged from −0.01 (calcium) to 0.59 (carbohydrates), and weighted Kappa exceeded 0.4 for 50% of nutrients. In short, TMC’s FFQ appears to have good relative validity for the assessment of nutrient intake among its participants, as compared to the three-day 24-h dietary recalls. However, estimates for iron, vitamin A, and vitamin C should be interpreted with caution.


Author(s):  
Brian TaeHyuk Keum ◽  
John L. Oliffe ◽  
Simon M. Rice ◽  
David Kealy ◽  
Zac E. Seidler ◽  
...  

AbstractWe examined whether men’s distress disclosure would be indirectly associated with psychological distress through feeling understood by others and loneliness as serial or parallel mediators. We conducted path analyses (N = 1827 adult men; mean 37.53 years, SD = 14.14) to test the mediators while controlling for race/ethnicity. Post-hoc multi-group analysis was conducted to examine differences across White and Asian men. The serial mediation model fit the data better than the parallel mediation model. Controlling for race/ethnicity, a significant partial indirect association was found between greater distress disclosure and lower psychological distress through greater feelings of being understood and lower feelings of loneliness. Post-hoc multi-group analysis suggested that the hypothesized paths fit equivalently across White and Asian men, and the direct effect was not significant for Asian men. Our hypothesized serial model also fit the data significantly better than alternative models with distress and the mediators predicting disclosure. Distress disclosure may be a socially conducive strategy for men to feel understood and socially connected, a process that may be associated with lower psychological distress.


2021 ◽  
pp. 175319342098321
Author(s):  
Anyuan Wang ◽  
Jian Ding ◽  
Long Wang ◽  
Tinggang Chu ◽  
Zhipeng Wu ◽  
...  

We present the MRI findings for 39 Wassel Type IV duplicated thumbs in 38 patients. We found that MRI revealed the morphology of the cartilaginous connection between the thumb anlages and the location of the deviation corresponding to the classification of Horii, which allowed precise preoperative planning of corrective osteotomies. All 39 thumbs were available for follow-up after surgical reconstruction at a mean of 29 months (range 25 to 39). Four out of nine Horii Type A cases and all 12 Type B, as well as the six Type C and the six Type D cases, achieved good results according to the Tada scoring system. Five Type A cases achieved fair results with residual stiffness of the interphalangeal joint. No secondary operations were needed. We conclude that MRI proved useful in subclassifying Wassel Type IV duplicated thumbs and may aid in planning the osteotomies needed for their reconstruction. Level of evidence: IV


Genus ◽  
2021 ◽  
Vol 77 (1) ◽  
Author(s):  
Andrea Priulla ◽  
Nicoletta D’Angelo ◽  
Massimo Attanasio

AbstractThis paper investigates gender differences in university performances in Science, Technology, Engineering and Mathematics (STEM) courses in Italy, proposing a novel application through the segmented regression models. The analysis concerns freshmen students enrolled at a 3-year STEM degree in Italian universities in the last decade, with a focus on the relationship between the number of university credits earned during the first year (a good predictor of the regularity of the career) and the probability of getting the bachelor degree within 4 years. Data is provided by the Italian Ministry of University and Research (MIUR). Our analysis confirms that first-year performance is strongly correlated to obtaining a degree within 4 years. Furthermore, our findings show that gender differences vary among STEM courses, in accordance with the care-oriented and technical-oriented dichotomy. Males outperform females in mathematics, physics, chemistry and computer science, while females are slightly better than males in biology. In engineering, female performance seems to follow the male stream. Finally, accounting for other important covariates regarding students, we point out the importance of high school background and students’ demographic characteristics.


2020 ◽  
Vol 41 (S1) ◽  
pp. s459-s461
Author(s):  
Valerie M Vaughn ◽  
Lindsay A. Petty ◽  
Tejal N. Gandhi ◽  
Keith S. Kaye ◽  
Anurag Malani ◽  
...  

Background: Nearly half of hospitalized patients with bacteriuria or treated for pneumonia receive unnecessary antibiotics (noninfectious or nonbacterial syndrome such as asymptomatic bacteriuria), excess duration (antibiotics prescribed for longer than necessary), or avoidable fluoroquinolones (safer alternative available) at hospital discharge.1–3 However, whether antibiotic overuse at discharge varies between hospitals or is associated with patient outcomes remains unknown. Methods: From July 2017 to December 2018, trained abstractors at 46 Michigan hospitals collected detailed data on a sample of adult, non–intensive care, hospitalized patients with bacteriuria (positive urine culture with or without symptoms) or treated for community-acquired pneumonia (CAP; includes those with the disease formerly known as healthcare-associated pneumonia [HCAP]). Antibiotic prescriptions at discharge were assessed for antibiotic overuse using a previously described, guideline-based hierarchical algorithm.3 Here, we report the proportion of patients discharged with antibiotic overuse by the hospital. We also assessed hospital-level correlation (using Pearson’s correlation coefficient) between antibiotic overuse at discharge for patients with bacteriuria and patients treated for CAP. Finally, we assessed the association of antibiotic overuse at discharge with patient outcomes (mortality, readmission, emergency department visit, and antibiotic-associated adverse events) at 30 days using logit generalized estimating equations adjusted for patient characteristics and probability of treatment. Results: Of 17,081 patients (7,207 with bacteriuria; 9,874 treated for pneumonia), nearly half (42.2%) had antibiotic overuse at discharge (36.3% bacteriuria and 51.1% pneumonia). The percentage of patients discharged with antibiotic overuse varied 5-fold among hospitals from 14.7% (95% CI, 8.0%–25.3%) to 74.3% (95% CI, 64.2%–83.8%). Hospital rates of antibiotic overuse at discharge were strongly correlated between bacteriuria and CAP (Pearson’s correlation coefficient, 0.76; P ≤ .001) (Fig. 1). In adjusted analyses, antibiotic overuse at discharge was not associated with death, readmission, emergency department visit, or Clostridioides difficile infection. However, each day of overuse was associated with a 5% increase in the odds of patient-reported antibiotic-associated adverse events after discharge (Fig. 2). Conclusions: Antibiotic overuse at discharge was common, varied widely between hospitals, and was associated with patient harm. Furthermore, antibiotic overuse at discharge was strongly correlated between 2 disparate diseases, suggesting that prescribing culture or discharge processes—rather than disease-specific factors—contribute to overprescribing at discharge. Thus, discharge stewardship may be needed to target multiple diseases.Funding: This study was supported by the Society for Healthcare Epidemiology of America and by Blue Cross Blue Shield of Michigan and Blue Care Network.Disclosures: Valerie M. Vaughn reports contracted research for Blue Cross and Blue Shield of Michigan, the Department of VA, the NIH, the SHEA, and the APIC. She also reports receipt of funds from the Gordon and Betty Moore Foundation Speaker’s Bureau, the CDC, the Pew Research Trust, Sepsis Alliance, and the Hospital and Health System Association of Pennsylvania.


1993 ◽  
Vol 13 (9) ◽  
pp. 5513-5523
Author(s):  
K Mizuno ◽  
K Hasegawa ◽  
T Katagiri ◽  
M Ogimoto ◽  
T Ichikawa ◽  
...  

Protein tyrosine phosphatases (PTPs), together with protein tyrosine kinases (PTKs), are involved in the regulation of cell activation, growth, and differentiation. To further elucidate the fine tuning of cell growth and differentiation through tyrosine phosphorylation, we tried to isolate mouse receptor-type PTP (RPTP) cDNA clones by screening mouse brain cDNA libraries with mouse CD45 PTP domain probes under reduced-stringency conditions. Characterization of isolated cDNA clones for RPTP showed that the cytoplasmic region contains two tandem repeats of PTP domain of about 230 amino acids with intrinsic phosphatase activity. The extracellular region was composed of immunoglobulin (Ig)-like domains and fibronectin type III (FN-III)-like domains. The gene was highly homologous to human PTP delta (HPTP delta) and thus was named MPTP delta (murine counterpart of HPTP delta). The MPTP delta gene appeared to generate at least three species of mRNA, which differ in the composition of the extracellular domain: type A, one Ig-like and four FN-III-like domains; type B, one Ig-like and eight FN-III-like domains; and type C, three Ig-like and eight FN-III-like domains. Interestingly, the 5' untranslated region and the leader peptide of types A and B were completely different from those of type C. Northern (RNA) blot analysis demonstrated that brain, kidney, and heart cells express three mRNA species of about 7 kb. Antibody directed against part of the extracellular domain of type A MPTP delta recognized a 210-kDa protein in brain and kidney lysates. In situ hybridization of brain samples revealed that MPTP delta mRNA is present in the hippocampus, thalamic reticular nucleus, and piriform cortex, where some Src family PTKs have been also demonstrated to exist. Although MPTP delta mRNA was not detected in lymphoid tissues, all of the pre-B-cell lines tested and one of three B-cell lines tested expressed MPTP delta mRNA, whereas antibody-producing B-cell hybridomas and T-cell and macrophage lines did not. Finally, the MPTP delta locus was tightly linked to the brown (b) locus on mouse chromosome 4.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Andrea Colli ◽  
Laura Besola ◽  
Lorenzo Bagozzi ◽  
Erica Manzan ◽  
Eleonora Bizzotto ◽  
...  

Introduction: TOP-MINI is a new micro invasive surgical procedure to treat degenerative mitral valve regurgitation due to flail/prolapse. Hypothesis: This prospective single centre study sought to assess the safety and effectiveness of the TOP-MINI procedure up to one year follow-up. Methods: Clinical and Echocardiographic outcomes were evaluated at 1, 3, 6 months and 1 year follow-up for all patients underwent TOP-MINI procedure from November 2013 to March 2015. Procedural success was defined as residual MR≤2+ at any time. Results: Sixty-one patients were treated during study period. One year survival was 96.7±2.3%. Freedom from MR>2+ is shown in figure 1 Panel A, Freedom from MR>2+ according to valve anatomy (Type A isolated P2 disease, Type B posterior multisegment disease, Type C anterior or bileaflet and/or calcified disease) is shown in Figure 1 Panel B. Freedom from MR>2+ according to STS risk profile is shown in Figure 2. The trend of Echocardiographic parameters is shown in Figure 3. Conclusions: TOP-MINI is a safe and effective procedure at 1 year FU. Residual MR is influenced by valve anatomy showing good results in Type A and B patients. Future techniques refinements are needed in order to improve outcomes of Type C patients. The lack of annuloplasty procedure does not influence negatively left ventricle reverse remodeling.


2013 ◽  
Vol 33 (8) ◽  
pp. 963-969 ◽  
Author(s):  
Eduardo C. Cruz Junior ◽  
Felipe M. Salvarani ◽  
Rodrigo O.S. Silva ◽  
Marcos X. Silva ◽  
Francisco C.F. Lobato ◽  
...  

The purpose of the study was to evaluate the real importance of anaerobic enteropathogens and rotavirus in contrast to more common agents as cause of diarrhea in piglets within the first week of life. Sixty 1- to 7-day-old piglets, 30 diarrheic and 30 non-diarrheic (control), from 15 different herds were selected, euthanized and necropsied. Samples of the jejunum, ileum, colon, cecum and feces were collected from the piglets and analyzed to determine the presence of the following enteropathogens: enterotoxigenic Escherichia coli (ETEC), Clostridium perfringens types A and C, Clostridium difficile, rotavirus and Isospora suis. Among diarrheic piglets, 23.3% were positive for C. difficile, 70% for C. perfringens type A cpb2+, 14.3% for rotavirus and 10% for ETEC. Among non-diarrheic control piglets, 10% were positive for C. difficile, 76.7% for C. perfringens type A cpb2+, 0% for rotavirus, 3.3% for ETEC and 3.3% for I. suis. C. perfringens type C was not detected in any of the animals. Histological lesions characteristic of C. difficile, E. coli and rotavirus were observed. However, no C. perfringens type A suggestive lesions were detected. There was a positive correlation between mesocolon edema and the presence of C. difficile toxins. Although C. perfringens type A cpb2+ was the most frequently detected enteropathogen, there was no association between its presence and diarrhea or macro or microscopic changes. C. difficile and Rotavirus were the most relevant pathogens involved with neonatal diarrhea in this study, and histopathology associated with microbiological test proved to be the key to reach a final diagnosis.


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