scholarly journals Mechanical Integrity of Hemodialysis Catheters after Exposure to a Novel Catheter Lock Solution

2010 ◽  
Vol 31 (11) ◽  
pp. 1124-1129 ◽  
Author(s):  
Saima Aslam ◽  
Rabih O. Darouiche
Keyword(s):  
Tensile Strength ◽  
Testing Machine ◽  
The Novel ◽  
Yield Strain ◽  
Time Intervals ◽  
Mechanical Integrity ◽  
Industry Standards ◽  
Lock Solution ◽  
Catheter Lock

Objective.To examine the mechanical integrity of hemodialysis catheters after exposure to the combination of N-acetylcysteine, ti-gecycline, and heparin, compared with that of catheters exposed to heparin alone.Methods.We used 3 types of hemodialysis catheters: polyurethane, silicone, and carbothane catheters. Catheter segments were incubated in vitro for various time intervals of up to 2 weeks either in a novel catheter lock solution (novel CLS), which consisted of N-acetylcysteine, tigecycline, and heparin, or in heparin alone (as a control). At the time of testing, each segment was rinsed and cut longitudinally into 2 sections. All catheter sections were scanned using an optical dissecting microscope to check for surface abnormalities and to measure wall thickness. We also carried out tensile strength testing of another set of catheters using a universal testing machine. Tested parameters included stress at yield, strain at yield, stress at break, strain at break, modulus of elasticity, and force at break.Results.The surfaces of catheters in both groups appeared similar by microscopy. The mean thickness of the catheter wall was not significantly different for the catheters exposed to the novel CLS and the catheters exposed to heparin (P >.05). Results for most of the tensile strength parameters tested were similar in the 2 groups of catheters at the end of 2 weeks of incubation. In particular, the force-at-break value of all tested catheters remained much greater than that recommended by industry standards.Conclusions.The use of the novel catheter lock solution did not impair the mechanical integrity or increase the propensity for fracture of hemodialysis catheters.

Comparison between traditional and alternative biocompatible welding techniques used in orthodontic devices

2020 ◽  
pp. 146531252097240
Author(s):  
Fernanda de Souza Henkin ◽  
Luciane Macedo de Menezes ◽  
Berenice Anina Dedavid ◽  
Cátia Abdo Quintão
Keyword(s):  
Tensile Strength ◽  
Laser Welding ◽  
Mechanical Performance ◽  
Steel Wire ◽  
Testing Machine ◽  
Mean Values ◽  
Welding Spot ◽  
Microstructural Morphology ◽  
Orthodontic Devices

Objective: To compare the mechanical strength of joints made by conventional soldering with those made by alternative, more biocompatible, methods (spot, tungsten inert gas [TIG] and laser welding), and to compare the microstructural morphology of wires welded with these techniques. Design: In vitro, laboratory study. Methods: Forty stainless-steel wire segments with 0.8-mm diameter were joined by silver soldering, spot, laser and TIG welding. Ten specimens were produced for each one. Tensile strength test was performed 24 h after welding on the Emic DL2000™ universal testing machine, using a load cell of 1000 N with a crosshead speed of 10 mm/min. Results: The highest tensile strength mean values were obtained with silver soldering (532 N), next were laser (420 N), spot (301 N) and TIG (296 N) welding. Statistically significant differences were observed between the groups; the Dunn post-hoc test revealed differences between laser and spot welding ( p=0.046), laser and TIG ( p = 0.016), spot and silver ( p <0.001), and silver and TIG ( p <0.001). Conclusion: Laser welding strength is high, and comparable to silver welding. Spot and TIG techniques present comparable and significantly lower strengths. The four methods presented resistance values compatible with orthodontic use. The microstructural morphology is different for each technique. The association between the mechanical performance and the microstructure evaluation shows that laser presented the highest quality joint.

scholarly journals Minocycline-EDTA-Ethanol Antimicrobial Catheter Lock Solution Is Highly Effective In Vitro for Eradication of Candida auris Biofilms

2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Ruth A. Reitzel ◽  
Joel Rosenblatt ◽  
Bahgat Z. Gerges ◽  
Nylev Vargas-Cruz ◽  
Issam I. Raad
Keyword(s):  
Therapeutic Option ◽  
Bloodstream Infections ◽  
Central Line ◽  
Emerging Pathogen ◽  
Candida Auris ◽  
Content Type ◽  
Lock Solution ◽  
Highly Effective ◽  
Catheter Lock

ABSTRACT Candida auris is an emerging pathogen that can cause virulent central-line-associated bloodstream infections. Catheter salvage through the eradication of biofilms is a desirable therapeutic option. We compared taurolidine and minocycline-EDTA-ethanol (MEE) catheter lock solutions in vitro for the eradication of biofilms of 10 C. auris strains. MEE fully eradicated all C. auris biofilms, while taurolidine lock partially eradicated all of the C. auris biofilms. The superiority was significant for all C. auris strains tested (P = 0.002).

scholarly journals A Biomechanical Evaluation of a Next-Generation Integrated and Modular ACDF Device Possessing Full-Plate, Half-Plate, and No-Profile Fixation Iterations

2019 ◽  
Vol 9 (8) ◽  
pp. 826-833
Author(s):  
Ripul Panchal ◽  
Anup Gandhi ◽  
Chris Ferry ◽  
Sam Farmer ◽  
Jeremy Hansmann ◽  
...  
Keyword(s):  
Plate Fixation ◽  
Testing Machine ◽  
Axial Rotation ◽  
Biomechanical Study ◽  
The Novel ◽  
Novel Device ◽  
Plate Group ◽  
Flexion Extension ◽  
Group 2

Study Design: In vitro biomechanical study. Objectives: The objective of this in vitro biomechanical range-of-motion (ROM) study was to evaluate spinal segmental stability following fixation with a novel anterior cervical discectomy and fusion (ACDF) device (“novel device”) that possesses integrated and modular no-profile, half-plate, and full-plate fixation capabilities. Methods: Human cadaveric (n = 18, C3-T1) specimens were divided into 3 groups (n = 6/group). Each group would receive one novel device iteration. Specimen terminal ends were potted. Each specimen was first tested in an intact state, followed by anterior discectomy (C5/C6) and iterative instrumentation. Testing order: (1) novel device (group 1, no-profile; group 2, half-plate; group 3, full-plate); (2) novel device (all groups) with lateral mass screws (LMS); (3) traditional ACDF plate + cage; (4) traditional ACDF plate + cage + LMS. A 2 N·m moment was applied in flexion/extension (FE), lateral bending (LB), and axial rotation (AR) via a kinematic testing machine. Segmental ROM was tracked and normalized to intact conditions. Comparative statistical analyses were performed. Results: Key findings: (1) the novel half- and full-plate constructs provided comparable reduction in FE and LB ROM to that of traditional plated ACDF ( P ≥ .05); (2) the novel full-plate construct significantly exceeded all other anterior-only constructs ( P ≤ .05) in AR ROM reduction; and (3) the novel half-plate construct significantly exceeded the no-profile construct in FE ( P < .05). Conclusions: The novel ACDF device may be a versatile alternative to traditional no-profile and independent plating techniques, as it provides comparable ROM reduction in all principle motion directions, across all device iterations.

scholarly journals In VitroandIn Vivoactivity of a novel catheter lock solution against bacterial and fungal biofilms

2018 ◽  
Author(s):  
Jyotsna Chandra ◽  
Lisa Long ◽  
Nancy Isham ◽  
Pranab K Mukherjee ◽  
Gino DiSciullo ◽  
...  
Keyword(s):  
Rabbit Model ◽  
Bloodstream Infections ◽  
Central Line ◽  
Saline Control ◽  
Resistant Bacteria ◽  
Lock Solution ◽  
Catheter Lock ◽  
Adhesion Phase

Central line associated bloodstream infections (CLABSIs) are increasingly recognized to be associated with intralumenal microbial biofilms, and effective measures for the prevention and treatment of BSI remain lacking. This report evaluates a new commercially developed antimicrobial catheter lock solution (ACL) containing trimethoprim (5 mg/ml) and ethanol (25%) and CA-EDTA 3% for activity against bacterial and fungal biofilms using in vitro and in vivo (rabbit) catheter biofilm models. Biofilms were formed with bacterial (seven different species including vancomycin-resistant enterococcus, VRE) or fungal (C. albicans) species on catheter materials. Biofilm formation was evaluated by quantitative culture (colony forming units, CFUs) and scanning electron microscopy (SEM). Treatment with ACL inhibited growth of adhesion phase biofilms in vitro after 60 min (VRE) or 15 min (all others), while mature biofilms were eradicated after exposure for 2 or 4 h, compared to control. Similar results were observed for drug-resistant bacteria. In the catheterized rabbit model, when compared against heparinized saline control, ACL lock therapy significantly reduced the catheter bacterial (3.49 ± 0.75 vs. 0.03 ± 0.06 log CFU/catheter, respectively; P = 0.001) and fungal burden (2.48 ± 1.60 vs. 0.55 ± 1.19 log CFU/catheter segment, respectively; P = 0.012). SEM also demonstrated eradication of bacterial and fungal biofilms in vivo on catheters exposed to ACL, while vigorous biofilms were observed on untreated control catheters. Our results demonstrate that ACL was efficacious against both adhesion phase and mature biofilms formed by bacteria and fungi in vitro as well as in vivo.

scholarly journals In Vitro and In Vivo Activity of a Novel Catheter Lock Solution against Bacterial and Fungal Biofilms

2018 ◽  
Vol 62 (8) ◽  
Author(s):  
J. Chandra ◽  
L. Long ◽  
N. Isham ◽  
P. K. Mukherjee ◽  
G. DiSciullo ◽  
...  
Keyword(s):  
Rabbit Model ◽  
Bloodstream Infections ◽  
Central Line ◽  
Resistant Bacteria ◽  
Content Type ◽  
Lock Solution ◽  
Catheter Lock ◽  
Adhesion Phase

ABSTRACT Central-line-associated bloodstream infections are increasingly recognized to be associated with intraluminal microbial biofilms, and effective measures for the prevention and treatment of bloodstream infections remain lacking. This report evaluates a new commercially developed antimicrobial catheter lock solution (ACL), containing trimethoprim (5 mg/ml), ethanol (25%), and calcium EDTA (Ca-EDTA) (3%), for activity against bacterial and fungal biofilms, using in vitro and in vivo (rabbit) catheter biofilm models. Biofilms were formed by bacterial (seven different species, including vancomycin-resistant Enterococcus [VRE]) or fungal (Candida albicans) species on catheter materials. Biofilm formation was evaluated by quantitative culture (CFU) and scanning electron microscopy (SEM). Treatment with ACL inhibited the growth of adhesion-phase biofilms in vitro after 60 min (VRE) or 15 min (all others), while mature biofilms were completely inhibited after exposure for 2 or 4 h, compared to control. Similar results were observed for drug-resistant bacteria. Compared to the heparinized saline controls, ACL lock therapy significantly reduced the catheter bacterial (3.49 ± 0.75 versus 0.03 ± 0.06 log CFU/catheter; P = 0.016) and fungal (2.48 ± 1.60 versus 0.55 ± 1.19 log CFU/catheter segment; P = 0.013) burdens in the catheterized rabbit model. SEM also demonstrated eradication of bacterial and fungal biofilms in vivo on catheters exposed to ACL, while vigorous biofilms were observed on untreated control catheters. Our results demonstrated that ACL was efficacious against both adhesion-phase and mature biofilms formed by bacteria and fungi in vitro and in vivo.

scholarly journals Evaluation of the Dislodgement Resistance of a New Pozzolan-Based Cement (EndoSeal MTA) Compared to ProRoot MTA and Biodentine in the Presence and Absence of Blood

Scanning ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Alireza Adl ◽  
Nooshin Sadat Shojaee ◽  
Negar Pourhatami
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Time Intervals ◽  
Failure Patterns ◽  
Tukey Test ◽  
Universal Testing ◽  
Presence And Absence ◽  
Type Of Failure ◽  
Push Out

Introduction. This in vitro study investigated the dislodgement resistance of EndoSeal MTA, a new pozzolan-containing calcium silicate-based material, in comparison with ProRoot MTA and Biodentine in the presence and absence of contamination with blood. Methods. Standard furcal perforations were created in 180 human mandibular first molars. The teeth were randomly allocated to 12 groups of 15 each. ProRoot MTA, Biodentine, and EndoSeal MTA were used to repair the perforations. In half of the samples, the walls of the perforated areas were contaminated with blood, whereas saline was injected into the other half. A push-out test was performed using a universal testing machine after 24 hours or 7 days. To evaluate failure patterns, the samples were split into half and were examined under a stereomicroscope at a 20x magnification. Data were analyzed using three-way analysis of variance, Tukey test, and Student’s t-test. Results. At both time intervals and in the presence and absence of contamination with blood, ProRoot MTA and Biodentine had significantly higher retention values than EndoSeal MTA (p<0.001). Contamination with blood had no effect on EndoSeal MTA; however, it negatively affected the dislodgement resistance of Biodentine at 24 hours and ProRoot MTA at both time intervals (p<0.05). Time significantly affected only the bond strength of the uncontaminated groups (p>0.001). The most common type of failure was mixed for ProRoot MTA and Biodentine, whereas it was cohesive for EndoSeal MTA. Conclusions. ProRoot MTA and Biodentine showed higher values of bond strength than EndoSeal MTA and may thus be better options for the repair of root perforations.

scholarly journals Tensile Strength of Glass Fiber Posts Submitted to Different Surface Treatments

2013 ◽  
Vol 24 (6) ◽  
pp. 626-629 ◽  
Author(s):  
Maria Isabel A. Faria ◽  
Erica Alves Gomes ◽  
Danielle Cristine Messias ◽  
Joao Manoel Silva Filho ◽  
Celso Bernardo Souza Filho ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Glass Fiber ◽  
Testing Machine ◽  
Surface Treatments ◽  
Significance Level ◽  
Fiber Posts ◽  
Group I ◽  
Significant Difference ◽  
Glass Fiber Posts

The aim of this in vitro study was to evaluate the tensile strength of glass fiber posts submitted to different surface treatments. Forty-eight maxillary canines had their crowns sectioned and root canals endodontically treated. The roots were embedded in acrylic resin and distributed into 3 groups according to the surface treatment: Group I: the posts were treated with silane agent for 30 s and adhesive; Group II: the posts were cleaned with alcohol before treatment with silane agent and adhesive; Group III: the posts were submitted to conditioning with 37% phosphoric acid for 30 s before treatment with silane agent and adhesive. Each group was divided into 2 subgroups for adhesive polymerization or not before insertion into the canal: A - adhesive was not light cured and B - adhesive was light cured. All posts were cemented with Panavia F and the samples were subjected to tensile strength test in a universal testing machine at crosshead speed of 1 mm/min. Data were submitted to one-way ANOVA and Tukey's test at 5% significance level. There was statistically significant difference (p<0.01) only between group GIII-B and groups GI-A and GI-B. No significant difference was found among the other groups (p>0.05). It was concluded that the products used for cleaning the posts influenced the retention regardless of adhesive light curing.

scholarly journals An in vitro Study to evaluate the Effects of Various Polymerizing Conditions on the Flexural Strength of Autopolymerizing Resins

2017 ◽  
Vol 8 (1) ◽  
pp. 15-19
Author(s):  
Sanjeev Singh, ◽  
Abid Z Hussain, ◽  
RU Thombare, ◽  
BK Motwani, ◽  
Shweta Singh,
Keyword(s):  
Flexural Strength ◽  
Constant Pressure ◽  
Testing Machine ◽  
In Vitro Study ◽  
Bending Test ◽  
Control Group ◽  
Time Interval ◽  
Time Intervals ◽  
Increased Strength

ABSTRACT Aim To investigate the effect of variation in temperature and time intervals on the flexural strength of two brands of autopolymerizing resins polymerized at constant pressure. Materials and methods Two autopolymerizing resins RR Cold Cure resin (DPI) and RR-Rapid Repair Powder (Dentsply) were used. A total of 20 samples were fabricated for each group. Samples were polymerized at temperature ranges of 40°, 50°, 60°, and 70°C and at time intervals of 5, 10, and 15 minutes in the customized curing pot, maintaining pressure of 30 psi. Results Flexural strength was verified using universal testing machine using three-point bending test and was then compared with all samples and also with the samples cured in open air (control group). The samples cured at higher temperature, i.e., 60° and 70°C, have shown increased strength than those at 40° and 50°C as well as control group. Time interval of 10 minutes is considered sufficient to increase the strength of the resin, as per the results of this study. Conclusion The samples cured under varied condition of time and temperature but under constant pressure showed increased strength than those cured in open air. Clinical significance The effect of pressure and temperature has been demonstrated, which could be utilized for enhancing the durability of the prosthesis fabricated from autopolymerized resins. How to cite this article Singh S, Hussain AZ, Thombare RU, Motwani BK, Singh S, Mangalekar SB. An in vitro Study to evaluate the Effects of Various Polymerizing Conditions on the Flexural Strength of Autopolymerizing Resins. J Health Sci Res 2017;8(1):15-19.

scholarly journals In Vitro Tensile Strength of Luting Cements on Metallic Substrate

2014 ◽  
Vol 25 (2) ◽  
pp. 136-140 ◽  
Author(s):  
Iara A. Orsi ◽  
Fernando K. Varoli ◽  
Carlos H.P. Pieroni ◽  
Marly C.C.G. Ferreira ◽  
Eduardo Borie
Keyword(s):  
Tensile Strength ◽  
Zinc Phosphate ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
Metallic Substrate ◽  
Resin Cement ◽  
Glass Ionomer ◽  
Luting Cements ◽  
Ionomer Cement

The aim of this study was to determine the tensile strength of crowns cemented on metallic substrate with four different types of luting agents. Twenty human maxillary molars with similar diameters were selected and prepared to receive metallic core castings (Cu-Al). After cementation and preparation the cores were measured and the area of crown's portion was calculated. The teeth were divided into four groups based on the luting agent used to cement the crowns: zinc phosphate cement; glass ionomer cement; resin cement Rely X; and resin cement Panavia F. The teeth with the crowns cemented were subjected to thermocycling and later to the tensile strength test using universal testing machine with a load cell of 200 kgf and a crosshead speed of 0.5 mm/min. The load required to dislodge the crowns was recorded and converted to MPa/mm2. Data were subjected to Kruskal-Wallis analysis with a significance level of 1%. Panavia F showed significantly higher retention in core casts (3.067 MPa/mm2), when compared with the other cements. Rely X showed a mean retention value of 1.877 MPa/mm2 and the zinc phosphate cement with 1.155 MPa/mm2. Glass ionomer cement (0.884 MPa/mm2) exhibited the lowest tensile strength value. Crowns cemented with Panavia F on cast metallic posts and cores presented higher tensile strength. The glass ionomer cement showed the lowest tensile strength among all the cements studied.

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