ABSTRACT
Abstract Objective The present study aims to evaluate the influence of different positioning of the hip femoral prosthesis on the stress and strain over this implant. Methods A femoral prosthesis (Taper - Víncula, Rio Claro, SP, Brazil) was submitted to a stress and strain analysis using the finite element method (FEM) according to the International Organization for Standardization (ISO) 7206-6 Implants for surgery - Partial and total hip joint prostheses - Part 6: Endurance properties testing and performance requirements of neck region of stemmed femoral components standard. The analysis proposed a branch of the physical test with a +/− 5° angle variation on the standard proposed for α and β variables. Results The isolated +/− 5° variation on the α angle, as well as the association of +/− 5° variation on the α and β angles, presented significant statistical differences compared with the control strain (p= 0.027 and 0.021, respectively). Variation on angle β alone did not result in a significant change in the strain of the prosthesis (p= 0.128). The stem positioning with greatest implant strain was α = 5° and β = 14° (p= 0.032). Conclusion A variation on the positioning of the prosthetic femoral stem by +/− 5° in the coronal plane and/or the association of a +/− 5° angle in coronal and sagittal planes significantly influenced implant strain.
Resumo Objetivo Avaliar a influência da variação do posicionamento da prótese femoral do quadril na tensão e na deformação produzidas neste implante. Métodos Utilizou-se a análise de tensão e de deformação da prótese femoral (Taper, Víncula, Rio Claro, SP, Brasil) pelo método de elementos finitos (MEF) de acordo com a norma ISO 7206-6 Implants for surgery - Partial and total hip joint prostheses-Part 6: Endurance properties testing and performance requirements of neck region of stemmed femoral components. A análise propôs uma ramificação do ensaio físico, com variação da angulação de +/− 5° sobre a proposta normativa das variáveis α e β. Resultados Ao comparar com a deformação controle, houve significância estatística com a angulação isolada de +/− 5° do ângulo α, bem como com a associação de +/− 5° nas angulações α e β (p= 0,027 e 0,021, respectivamente). Já com a variação apenas do ângulo β, não houve variação significativa na deformação da prótese (p= 0,128). A posição da haste com maior deformação no implante foi com α = 5° e β = 14° (p= 0,032). Conclusão A variabilidade de posicionamento da haste femoral protética de +/− 5° no plano coronal e/ou a associação da angulação de +/− 5° nos planos coronal e sagital interferiu de forma significativa na deformação do implante.
Subject(s)
Humans , Equipment Failure Analysis , Arthroplasty, Replacement, Hip/adverse effects , Finite Element Analysis , Hip ProsthesisABSTRACT
Objective: The aim of this study was to investigate loose brackets in relation to various related factors in orthodontic patients who had completed orthodontic treatment. Material and Methods: In this retrospective study, 738 medical records of patients who had undergone comprehensive orthodontic treatment and matched specific inclusion criteria were selected. Paired t-tests and ANOVA, along with the Mann-Whitney test and KruskalWallis analyses were performed to compare the means of variables between selected subgroups. Results: Loose brackets were found most frequently on premolars, followed by incisors and then canines (p<0.01). Male and young patients were found to have a higher incidence of loose brackets compared to female and adult patients (p=0.044 and p<0.01, respectively). The highest correlation coefficient value was found between treatment duration and total number of loose brackets (0.393), which was statistically significant. Conclusions: The frequency of total number of loose brackets increased with younger age group. Premolar teeth were found to be the most commonly affected teeth, followed by incisors and canines. Mandibular teeth presented more loose brackets than maxillary.
Objetivo: Fue investigar brackets sueltos en relación con varios factores relacionados en pacientes ortodónticos que habían completado el tratamiento de ortodoncia. Material y Métodos: En este estudio retrospectivo, se seleccionaron 738 registros médicos de pacientes que se habían sometido a un tratamiento ortodóntico integral y criterios de inclusión específicos coincidentes. Se realizaron pruebas t pareadas y ANOVA, junto con la prueba de Mann-Whitney y los análisis de Kruskal-Wallis para comparar las medias de las variables entre los subgrupos seleccionados. Resultados: Se encontraron corchetes sueltos con mayor frecuencia en los premolares, seguidos de incisivos y luego caninos (p<0.01). Se encontró que los pacientes masculinos y jóvenes tenían una mayor incidencia de corchetes sueltos en comparación con los pacientes femeninos y adultos (p=0.044 y p<0.01, respectivamente). El valor del coeficiente de correlación más alto se encontró entre la duración del tratamiento y el número total de corchetes sueltos (0.393), que fue estadísticamente significativo. Conclusiones: La frecuencia del número total de corchetes sueltos aumentó con el grupo de edad más joven. Los dientes premolares fueron los dientes más afectados, seguidos de los incisivos y los caninos. Los dientes mandibulares presentan más brackets sueltos que los maxilares.
Subject(s)
Humans , Male , Female , Child , Adolescent , Adult , Middle Aged , Young Adult , Orthodontic Brackets , Ligation/instrumentation , Saudi Arabia , Retrospective Studies , Cohort Studies , Treatment Outcome , Equipment Failure AnalysisABSTRACT
Abstract: This study aimed to assess the cyclic fatigue resistance of Genius and EdgeFile X1 reciprocating instruments compared with WaveOne Gold Primary. Twenty Genius (Ultradent) 25.04, 20 Genius 30.04, 20 EdgeFile X1 (EdgeEndo) and 20 WaveOne Gold Primary (Dentsply Maillefer) instruments were included in this study and tested in a static cyclic fatigue testing device, which has an artificial stainless steel canal with a 60° angle of curvature and a 5-mm radius of curvature. All instruments were operated in reciprocation mode until fracture occurred. The number of cycles to failure (NCF) was calculated and time to fracture (TF) was recorded in seconds using a digital chronometer. The mean and standard deviations of NCF and TF were calculated for each reciprocating system and the data were subjected to Kruskal-Wallis one-way analysis of variance and to Dunn's test (p < .05) using SigmaPlot software (Systat software, CA, USA). The fractured surfaces of five instruments from each brand were randomly examined and microphotographed by a low-vacuum environmental scanning electron microscopy - SEM (Tabletop Microscope TM3030, Hitachi, Japan) to confirm the cyclic fatigue fracture. EdgeFile exhibited the highest cyclic fatigue resistance, followed by both Genius files (p < .05). Within the limitations of this in vitro study, EdgeFile X1 instruments had significantly higher cyclic fatigue resistance than did Genius and WaveOne Gold Primary instruments. The cyclic fatigue resistance of both Genius files was higher than that of WaveOne Gold Primary.
Subject(s)
Titanium/chemistry , Root Canal Preparation/instrumentation , Dental Instruments/standards , Nickel/chemistry , Reference Values , Stress, Mechanical , Surface Properties , Time Factors , Materials Testing , Microscopy, Electron, Scanning , Statistics, Nonparametric , Equipment Failure Analysis , Equipment DesignABSTRACT
Abstract To evaluate the torsional properties of engine-driven pathfinding instruments manufactured from different NiTi alloys - R-Pilot (tip size 12.5;.04 taper; M-Wire) and One G (tip size 14;.03 taper; Conventional NiTi). A total of 40 NiTi instruments from engine-driven pathfinding instruments (n = 20) were used. The torsion tests followed ISO 3630-1 (1992). Three millimeters of each instrument tip was fastened to a small load cell by a lever arm linked to the axis of torsion. During the test, the torsion testing machine software measured the maximum torsional strength and angle of rotation (0) before instrument failure. The fractured surface of each instrument was assessed by scanning electron microscopy (SEM). In addition, a supplementary examination was performed to measure the cross-sectional area and the metal mass volume of each instrument 3 mm from the tip. Data were analyzed using a t-test, with significance level set at 5%. R-pilot had significantly higher torsional strength than did One G (p < 0.05). Regarding the angle of rotation to fracture, One G had higher angles than did R-Pilot (p < 0.05). The supplementary examination showed that R-Pilot had the highest cross-sectional area and volume of metal mass at 3 mm from the tip (p < 0.05). R-pilot (M-Wire NiTi alloy) had a significantly higher torsional strength and One-G (superelastic NiTi alloy) had the highest angle of rotation to fracture.
Subject(s)
Root Canal Preparation/instrumentation , Dental Alloys/chemistry , Dental Instruments , Alloys/chemistry , Reference Values , Stress, Mechanical , Surface Properties , Materials Testing , Microscopy, Electron, Scanning , Reproducibility of Results , Analysis of Variance , Statistics, Nonparametric , Equipment Failure Analysis , Torque , Equipment DesignABSTRACT
Abstract This study evaluated the effectiveness of a multi-mode adhesive (SBU-Scotch Bond Universal/3M) as a substitute for silica coating and silane application on the bonding of zirconia ceramics to resin cement. One-hundred and twenty sintered zirconia ceramic blocks (5 x 5 x 5 mm) were obtained, finished by grounding with silicon carbide paper (#600, #800, #1000 and #1200) and randomly divided into 12 groups (n=10) in accordance with the factors "surface treatment" (ScSi - silicatization + silanization; ScSBU - silicatization + SBU; SBU - SBU without photoactivation and SBUp - SBU photoactivated) and "ceramic" (Lava / 3M ESPE, Ceramill Zirconia / Amann Girrbach and Zirkonzahn / Zirkonzahn). Dual resin cement cylinders (RelyX Ultimate/3M ESPE) were subsequently produced in the center of each block using a silicon matrix (Ø=2 mm, h=5 mm) and photoactivated for 40 s (1200 mW/cm2). The samples were stored for 30 days in distilled water (37ºC) and submitted to shear bond strength test (1 mm/min, 100 KgF). Data (MPa) were analyzed under ANOVA (2 levels) and Tukey test (5%). Complementary analyzes were also performed. ANOVA revealed that only the factor "surface treatment" was significant (p=0.0001). The ScSi treatment (14.28A) promoted statistically higher bond strength values than the other ScSBU (9.03B), SBU (8.47B) and SBUp (7.82B), which were similar to each other (Tukey). Failure analysis revealed that 100% of the failures were mixed. The silica coating followed by the silanization promoted higher bond strength values of resin cement and ceramic, regardless of the zirconia ceramic or SBU.
Resumo Este estudo avaliou a efetividade de um adesivo "multi-mode" (Single Bond Universal/3M) como um substituto para a silicatização e aplicação do silano na resistência de união das cerâmicas de zircônia e um cimento resinoso. Para isso, 120 blocos cerâmicos sinterizados de zircônia nas dimensões de (5 x 5 x 5 mm) foram obtidos, lixados com lixas de granulação decrescente (#600, #800, #1000 e #1200) e divididos aleatoriamente em 12 grupos (n = 10), de acordo com os fatores "tratamento de superfície" (ScSi - silicatização + silanização; ScSBU - silicatização + Single Bond; SBU - SBU sem fotoativação e SBUp - SBU com fotoativação) e "cerâmica" (Lava/3M ESPE, Ceramill Zircônia/ Amann Girrbach e Zirkonzahn/Zirkonzahn). Posteriormente, cilindros de cimento resinoso dual (RelyX Ultimate/3M ESPE) foram confeccionados no centro de cada bloco com auxílio de uma matriz de silicone (Ø=2 mm; h=5 mm) e fotopolimerizados por 40 s (1200 mW/ cm²). Em seguida, as amostras foram armazenadas durante trinta dias em água destilada (37 °C) e submetidas ao ensaio de resistência de união ao cisalhamento (1 mm/min, 100 kgF). Os dados (MPa) foram analisados sob ANOVA (2 fatores) e teste de Tukey (5%). Análises complementares também foram realizadas. ANOVA revelou que apenas o fator "tratamento de superfície" foi significativo (p=0,0001). O tratamento ScSi (14.28A) promoveu valores de adesão estatisticamente superiores aos demais ScSBU (9.03B), SBU (8.47B) e SBUp (7.82B), os quais foram semelhantes entre si (Tukey). A Análise de falhas revelou que 100% da falhas que ocorreram foram mistas. A silicatização seguida da silanização promoveu a melhor resistência de união entre cimento resinoso e a cerâmica, independentemente do tipo da cerâmica ou do SBU.
Subject(s)
Silanes/chemistry , Yttrium , Zirconium , Silicates/chemistry , Dental Cements , Spectrometry, X-Ray Emission , Tensile Strength , X-Ray Diffraction , Dental Bonding , Wettability , Resin Cements/chemistry , Equipment Failure Analysis , Shear Strength , Dental Stress AnalysisABSTRACT
OBJECTIVE@#The aim of the current study was to evaluate the effect of ultraviolet (UV) photofunctionalization of dental titanium implants with exposure to the oral cavity on osseointegration in an animal model.@*METHODS@#Forty-eight titanium implants (Camlog Conelog 4.3 mmx9.0 mm) were placed epicrestally into the edentulous jaws of three minipigs and implant stability was assessed by measuring the implant stability quotient (ISQ). Prior to implantation half of the implants were photofunctionalized with intense UV-light. After three months, the implants were exposed and ISQ was measured again. After six months of implant exposure, the minipigs were sacrificed and the harvested specimens were analyzed using histomorphometric, light, and fluorescence microscopy.@*MAIN RESULTS@#Forty-two of 48 implants osseointegrated. The overall mean bone-implant contact area (BIC) was (64±22)%. No significant differences were found in BIC or ISQ value (multivariate analysis of variance (MANOVA), P>0.05) between implants with and without exposure to UV photofunctionalization.@*CONCLUSIONS@#No significant effects were observed on osseointegration of dental titanium implants nine months after exposure of UV photofunctionalization.
Subject(s)
Animals , Female , Male , Dental Implantation, Endosseous , Methods , Dental Implants , Equipment Failure Analysis , Hydrophobic and Hydrophilic Interactions , Models, Animal , Osseointegration , Surface Properties , Swine , Swine, Miniature , Titanium , Ultraviolet RaysABSTRACT
PURPOSE: The purpose of this study was to evaluate the repeatability and matching accuracy between two identical intraoral spectrophotometers. MATERIALS AND METHODS: The maxillary right central incisor, canine, and mandibular left central incisor of each of 30 patients were measured using 2 identical intraoral spectrophotometers with different serial numbers (EasyShade V). The color of each shade tab from 3 shade guides (VITA 3D-Master) was also determined with both devices. All measurements were performed by a single operator. Statistical analyses were performed to verify the repeatability, accuracy, and the differences between the devices with paired t-tests, one-way ANOVA, and intra-class correlation coefficients (ICCs) (α=.05). RESULTS: A high level of measurement repeatability (ICC>0.90) among L *, a *, and b * color components was observed within and between devices (P < .001). Intra-device matching agreement rates were 80.00% and 81.11%, respectively, while inter-device matching agreement rate was 51.85%. ANOVA revealed no significant different color values within each device, while paired t-test provided significant different color values between both devices. The CIEDE2000 color differences between both devices were 2.28±1.61 ΔE 00 for in-vivo readings. Regarding the clinical matching accuracy of both devices, ΔE 00 values between teeth and matching shade tabs were 3.05±1.19 and 2.86±1.02, respectively. CONCLUSION: Although two EasyShade V devices with different serial numbers show high repeatability of CIE L*, a*, and b* measurements, they could provide different color values and shade for the same tooth.
Subject(s)
Humans , Dimensional Measurement Accuracy , Equipment Failure Analysis , In Vitro Techniques , Incisor , Reading , Spectrophotometry , ToothABSTRACT
ABSTRACT Objective: This study aimed at evaluating the design and dimensions of five different brands of orthodontic mini-implants, as well as their influence on torsional fracture strength. Methods: Fifty mini-implants were divided into five groups corresponding to different manufactures (DEN, RMO, CON, NEO, SIN). Twenty-five mini-implants were subjected to fracture test by torsion in the neck and the tip, through arbors attached to a Universal Mechanical Testing Machine. The other 25 mini-implants were subjected to insertion torque test into blocks of pork ribs using a torquimeter and contra-angle handpiece mounted in a surgical motor. The shape of the active tip of the mini-implants was evaluated under microscopy. The non-parametric Friedman test and Snedecor's F in analysis of variance (ANOVA) were used to evaluate the differences between groups. Results: The fracture torque of the neck ranged from 23.45 N.cm (DEN) to 34.82 N.cm (SIN), and of the tip ranged from 9.35 N.cm (CON) to 24.36 N.cm (NEO). Insertion torque values ranged from 6.6 N.cm (RMO) to 10.2 N.cm (NEO). The characteristics that most influenced the results were outer diameter, inner diameter, the ratio between internal and external diameters, and the existence of milling in the apical region of the mini-implant. Conclusions: The fracture torques were different for both the neck and the tip of the five types evaluated. NEO and SIN mini-implants showed the highest resistance to fracture of the neck and tip. The fracture torques of both tip and neck were higher than the torque required to insert mini-implants.
RESUMO Objetivo: o objetivo do presente estudo foi avaliar o desenho e as medidas de cinco marcas diferentes de mini-implantes ortodônticos, e sua influência na resistência à fratura em torção. Métodos: cinquenta mini-implantes foram divididos em cinco grupos, correspondentes a diferentes fabricantes (DEN, Dentaurum; RMO, Rocky Mountain Orthodontics; CON, Conexão; NEO, Neodent; SIN, Sistema de Implantes Nacional). Vinte e cinco mini-implantes foram submetidos ao teste de fratura por torção no pescoço e na ponta, com mandris fixados a uma máquina universal de testes mecânicos. Os outros 25 mini-implantes foram submetidos ao teste de torque de inserção em blocos de costelas suínas, utilizando-se um torquímetro e um contra-ângulo montado em motor cirúrgico. O formato da ponta ativa dos mini-implantes foi avaliado por microscopia. O teste não-paramétrico de Friedman e o teste F de Snedecor na análise de variância (ANOVA) foram utilizados para avaliar as diferenças entre os grupos. Resultados: o torque de fratura do pescoço variou de 23,45 N.cm (DEN) a 34,82 N.cm (SIN); e o da ponta, entre 9,35 N.cm (CON) e 24,36 N.cm (NEO). O valor do torque de inserção variou de 6,6 N.cm (RMO) a 10,2 N.cm (NEO). As características que mais influenciaram os resultados foram: diâmetro externo, diâmetro interno, razão entre o diâmetro interno e o externo, e a presença de fresagem na região apical do mini-implante. Conclusões: os torques de fratura foram diferentes entre os cinco tipos avaliados, tanto no pescoço quanto na ponta. Os mini-implantes NEO e SIN foram os mais resistentes à fratura do pescoço e da ponta. Os torques de fratura tanto na ponta quanto no pescoço foram maiores do que o torque necessário para a inserção dos mini-implantes.
Subject(s)
Animals , Dental Implants , Orthodontic Appliance Design , Orthodontic Anchorage Procedures/instrumentation , Ribs , Spectrometry, X-Ray Emission , Stress, Mechanical , Surface Properties , Swine , In Vitro Techniques , Materials Testing , Brazil , Microscopy, Electron, Scanning , Equipment Failure Analysis , Torque , Dental Stress AnalysisABSTRACT
Abstract This in vitro study evaluated the cutting ability of reciprocating files and the deformations caused by their multiple use. Five Reciproc® R25 files were divided into five groups for 10 simulated root canal preparations each. The resin blocks were weighed and photographed (12.5X and 20X) before and after preparation. The canals were prepared according to the manufacturer’s instructions. Enlargement of the root canals was evaluated by comparison of pre- and post-preparation images using a computer software. The preoperative and postoperative weight differences determined the cutting ability of repeatedly used instruments. The data were analyzed using Lilliefors and Friedman statistical tests. The cutting ability and enlargement of the canals gradually decreased after each use, with significant differences observed at the 8th and 9th repetitions, respectively. There was no evidence of file deformation. The cutting ability and enlargement of the simulated canals gradually decreased when a reciprocating file was used up to 10 times.
Subject(s)
Dental Instruments , Root Canal Preparation/instrumentation , Equipment Design , Equipment Failure Analysis , Materials Testing , Plastics/chemistry , Time FactorsABSTRACT
In this paper, the common errors in medical devices test reports are classified and analyzed. And then the main 11 influence factors for these inspection report errors are summarized. The hierarchy model was also developed and verified by presentation data using MATLAB. The feasibility of comprehensive weights quantitative comparison has been analyzed by using the analytic hierarchy process. In the end, this paper porspects the further research direction.
Subject(s)
Equipment Failure Analysis , Equipment and Supplies , Reference Standards , Models, TheoreticalABSTRACT
The objective of this study was to assess the influence of cortical thickness and bone density on the insertion torque of a mini-implant (MI) with microthreads. Mini-implants with lengths of 6 and 8 mm in the active part were inserted into synthetic bone blocks (polyurethane resin). The density of these blocks was 20 pounds per cubic foot (pcf), simulating bone marrow, and that of blocks 1, 2, and 3-mm-thick blocks was 40 pcf, simulating cortical bone. Blocks with uniform density of 40 pcf were also used to simulate bone areas of greater density. Insertion torque was quantified with a universal testing machine (EMIC). For both MIs, increasing insertion torque was associated with increasing cortical bone thickness. For the same MI length, significant differences were observed among all assessed groups. The insertion torque of the 6-mm-long MI inserted in a 3-mm-thick cortical bone was equivalent to that of the 8-mm-long MI inserted in a 1-mm-thick cortical bone. MIs inserted in bone blocks of greater density presented insertion torque values almost twice as high as those in other groups. The shorter MI, the lower the insertion torque, and the greater the cortical bone thickness, the greater the insertion torque. To minimize fracture risk, the size of MI should be selected according to the insertion site.
Subject(s)
Humans , Dental Implants , Orthodontic Anchorage Procedures/methods , Torque , Analysis of Variance , Bone Density , Bone and Bones/anatomy & histology , Dental Stress Analysis , Equipment Failure Analysis , Materials Testing , Orthodontic Appliance Design , Orthodontic Anchorage Procedures/instrumentation , Reference Values , Risk Factors , Statistics, Nonparametric , Surface PropertiesABSTRACT
This study aimed to investigate the causes and managements of the fractures and migrations of the implantable venous access port catheter (IVAPC). The fracture or migration of IVAPC occurred in 4 patients who were treated between May 2012 and January 2014 in Union Hospital, Wuhan, China. The port catheter leakage was found in 2 cases during drug infusion. Catheters that dislodged to the superior vena cava and right atrium were confirmed by port angiogram. The two dislodged catheters were successfully retrieved by interventional procedures. Catheter fracture occurred in two cases during port removal. One catheter was eventually removed from the subclavian vein through right clavicle osteotomy and subclavian venotomy, and the other removed by external jugular venotomy. Flushing the port in high pressure and injury of the totally implantable venous access port (TIVP) during implantation are usually responsible for catheter displacement. Interventional retrieval procedure can be used if the catheter dislodges to the vena cava and right atrium. Catheter fracture may occur during removal if clipping syndrome occurs or the catheter is sutured very tight during implantation.
Subject(s)
Child , Child, Preschool , Female , Humans , Male , Middle Aged , Young Adult , Angiography , Catheters, Indwelling , Central Venous Catheters , Device Removal , Methods , Equipment Failure , Equipment Failure Analysis , Heart Atria , Diagnostic Imaging , General Surgery , Osteotomy , Methods , Suture Techniques , Vena Cava, Superior , Diagnostic Imaging , General SurgeryABSTRACT
To evaluate the fatigue behavior of nitinol stents, we used the finite element method to simulate the manufacture processes of nitinol stents, including expanding, annealing, crimping, and releasing procedure in applications of the clinical treatments. Meanwhile, we also studied the effect of the crown area dimension of stent on strain distribution. We then applied a fatigue diagram to investigate the fatigue characteristics of nitinol stents. The results showed that the maximum strain of all three stent structures, which had different crown area dimensions under vessel loads, located at the transition area between the crown and the strut, but comparable deformation appeared at the inner side of the crown area center. The cause, of these results was that the difference of the area moment of inertia determined by the crown dimension induced the difference of strain distribution in stent structure. Moreover, it can be drawn from the fatigue diagrams that the fatigue performance got the best result when the crown area dimension equaled to the intermediate value. The above results proved that the fatigue property of nitinol stent had a close relationship with the dimension of stent crown area, but there was no positive correlation.
Subject(s)
Alloys , Computer Simulation , Equipment Failure Analysis , Finite Element Analysis , StentsABSTRACT
Objective: Discomfort and noncompliance with noninvasive ventilation (NIV) interfaces are obstacles to NIV success. Total face masks (TFMs) are considered to be a very comfortable NIV interface. However, due to their large internal volume and consequent increased CO2 rebreathing, their orifices allow proximal leaks to enhance CO2 elimination. The ventilators used in the ICU might not adequately compensate for such leakage. In this study, we attempted to determine whether ICU ventilators in NIV mode are suitable for use with a leaky TFM. Methods: This was a bench study carried out in a university research laboratory. Eight ICU ventilators equipped with NIV mode and one NIV ventilator were connected to a TFM with major leaks. All were tested at two positive end-expiratory pressure (PEEP) levels and three pressure support levels. The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization. Results: Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection); three worked with some problems (low PEEP or high cycling delay); and one worked properly. Conclusions: The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM. .
Objetivo: O desconforto e a falta de adaptação às interfaces de ventilação não invasiva (VNI) são obstáculos ao sucesso da VNI. A máscara facial total (MFT) é uma interface de VNI considerada muito confortável. No entanto, devido a seu grande volume interno e, consequentemente, ao aumento da reinalação de CO2, a MFT tem orifícios que permitem vazamentos proximais para melhorar a eliminação de CO2. É possível que os ventiladores usados na UTI não compensem esse vazamento adequadamente. Neste estudo, buscamos determinar se ventiladores de UTI com módulo de VNI podem ser usados com MFT com grandes vazamentos. Métodos: Estudo em simulador mecânico conduzido em um laboratório universitário de pesquisa. Oito ventiladores de UTI equipados para realizar VNI e um ventilador específico para VNI foram conectados a uma MFT com grandes vazamentos. Todos foram testados com dois níveis de positive end-expiratory pressure (PEEP, pressão expiratória final positiva) e três níveis de pressão de suporte. As variáveis analisadas foram disparo do ventilador, ciclagem, vazamento total e pressurização. Resultados: Dos oito ventiladores de UTI, quatro não funcionaram (autodisparo ou desligamento inapropriado por detecção incorreta de desconexão), três funcionaram com alguns problemas (valores baixos de PEEP ou grande atraso na ciclagem do ventilador) e apenas um funcionou adequadamente. Conclusões: A maioria dos ventiladores de UTI testados mostrou-se inadequada para VNI com MFT com grandes vazamentos. .
Subject(s)
Humans , Equipment Failure Analysis/standards , Masks/standards , Noninvasive Ventilation/instrumentation , Ventilators, Mechanical/standards , Computer Simulation , Equipment Design , Equipment Failure Analysis/methods , Intensive Care Units , Models, Biological , Masks/adverse effects , Noninvasive Ventilation/adverse effects , Ventilators, Mechanical/adverse effectsABSTRACT
Objective: The aim of this article was to assess how intraoral biodegradation influenced the surface characteristics and friction levels of metallic brackets used during 12 and 24 months of orthodontic treatment and also to compare the static friction generated in these brackets with four different methods of the ligation of orthodontic wires. Material and Methods: Seventy premolar brackets as received from the manufacturer and 224 brackets that were used in previous orthodontic treatments were evaluated in this experiment. The surface morphology and the composition of the deposits found in the brackets were evaluated with rugosimetry, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Friction was analyzed by applying tensile tests simulating sliding mechanics with a 0.019x0.025" steel wire. The static friction levels produced by the following ligation methods were evaluated: loosely attached steel ligature around all four bracket wings, steel ligature attached to only two wings, conventional elastomeric ligation around all 4 bracket wings, and non-conventional Slide® elastomeric ligature. Results: The results demonstrated the presence of biodegradation effects such as corrosion pits, plastic deformation, cracks, and material deposits. The main chemical elements found on these deposits were Carbon and Oxygen. The maximum friction produced by each ligation method changed according to the time of intraoral use. The steel ligature loosely attached to all four bracket wings produced the lowest friction levels in the new brackets. The conventional elastic ligatures generated the highest friction levels. The metallic brackets underwent significant degradation during orthodontic treatment, showing an increase in surface roughness and the deposit of chemical elements on the surface. Conclusion: The levels of static friction decreased with use. The non-conventional elastic ligatures were the best alternative to ...
Subject(s)
Humans , Adult , Equipment Failure Analysis/methods , Friction , Orthodontic Appliance Design , Orthodontic Brackets , Orthodontic Wires , Analysis of Variance , Elastomers/chemistry , Materials Testing , Microscopy, Electron, Scanning , Spectrometry, X-Ray Emission , Stainless Steel/chemistry , Statistics, Nonparametric , Surface Properties , Time FactorsABSTRACT
Report of a rare complication - fracture of the pedicles - in a patient with total disc replacement of L5-S1, a surgical resolution, and a biomechanical explanation. To the authors' knowledge, there is only one previous report of bilateral fracture of the pedicles in the literature, as a complication in total disc replacement of the lumbar spine. In this case, no direct repair was made to the fracture site; instead intersomatic fusion was performed by the anterior approach. A 40-year-old male, a martial arts practitioner who had undergone L5-S1 (ProDisc®) disc replacement nine months earlier, with complete resolution of the preoperative symptoms and no complications, sudden pain during physical activity, without neurological symptoms. Computed axial tomography showed a fracture of the L5 pedicles and anterior luxation of the polyethylene insert. Surgery was performed by the posterior approach, with direct repair of the fractures and posterolateral fusion of L5-S1 with transpedicular screws (Schanz) and USS® internal fixator. A follow-up axial CT scan at 6 months after surgery showed complete consolidation of the fractures, and the patient was asymptomatic. Due to the alteration in weight transmission through the anterior part of the spine in the total replacement of the lumbar disc, which preserves the movement but not the absorption of forces, the pedicle becomes more susceptible to fracture. It is important to bear this complication in patients submitted to this procedure.
Relato de uma complicação rara - fratura de pedículos - em paciente com prótese de disco L5-S1, sua resolução cirúrgica e uma explicação biomecânica. Até onde os autores sabem, existe na literatura apenas um relato anterior de fratura bilateral de pedículos como complicação de substituição total de disco lombar; neste caso, não se realizou reparo direto da fratura, e sim, fusão intersomática por acesso anterior. Paciente do sexo masculino, com 40 anos de idade, praticante de artes marciais e com antecedente de prótese de disco L5-S1 (ProDisc®) há nove meses, atinge melhora completa dos sintomas pré-operatórios sem complicações, apresenta dor súbita ao realizar atividade física sem intercorrências neurológicas. Na tomografia axial computadorizada, observa-se fratura de pedículos L5 e luxação anterior do inxerto de polietileno. Realiza-se cirurgia por acesso posterior com reparo direto das fraturas e fusão posterolateral de L5-S1 com parafusos transpediculares tipo Schanz e fixador interno USS®. A TC axial de acompanhamento 6 meses depois da cirurgia mostra consolidação completa das fraturas, e o paciente está assintomático. Devido à alteração da transmissão de cargas através da parte anterior da coluna vertebral na substituição total de disco lombar, que preserva o movimento, mas não a absorção de forças, o pedículo fica mais suscetível à fratura, e é preciso considerar essa complicação em pacientes submetidos a esse procedimento.
Reporte de una rara complicación, fractura de pedículos, en un paciente con prótesis de disco L5-S1, la resolución quirúrgica y una explicación biomecánica. En el conocimiento de los autores, solo existe un reporte previo en la literatura de una fractura bilateral de pedículos como complicación de un reemplazo total de disco lumbar; en dicho caso no se realizó una reparación directa de la fractura, sino una fusión intersomática por vía anterior. Paciente masculino de 40 años de edad, practicante de artes marciales, con antecedente de prótesis de disco L5-S1 L nueve meses atrás, alcanza mejoría total de los síntomas preoperatorios sin complicaciones, presenta dolor súbito al realizar actividad física sin datos neurológicos. En la TAC se observa fractura de pedículos L5 y luxación anterior del inserto de polietileno. Se realiza cirugía por vía posterior con reparación directa de las fracturas y fusión posterolateral L5-S1 mediante tornillos transpediculares tipo Schanz y fijador interno USS®. La TAC de seguimiento a 6 meses de la cirugía muestra una consolidación completa de las fracturas y el paciente se encuentra asintomático. Debido a la alteración en la transmisión de las cargas a través de la porción anterior de la columna vertebral en el reemplazo total de disco lumbar, ya que este preserva el movimiento pero no la absorción de fuerzas, el pedículo es más susceptible a la fractura, es por ello que se debe tener en cuenta esta complicación en pacientes sometidos a dicho procedimiento.
Subject(s)
Humans , Male , Adult , Total Disc Replacement/adverse effects , Spinal Fusion , Equipment Failure Analysis , Pedicle ScrewsABSTRACT
In an effort to overcome the drawbacks of distraction osteogenesis using the Ilizarov external fixator, intramedullary lengthening devices have been developed and applied for long bone distraction osteogenesis. Several successful cases have been reported, leading to the next generation of distraction osteogenesis. However, intramedullary lengthening devices have their own problems, such as device failure, difficulty of control of the lengthening degree. The authors report on a case of device failure during distraction osteogenesis using ISKD(R) (Orthofix Inc.) in the distraction phase, and the strategy that involved switching to a lengthening over nail system, which uses the Ilizarov external fixator, in order to obtain the target length.
Subject(s)
Equipment Failure , Equipment Failure Analysis , External Fixators , Osteogenesis, DistractionABSTRACT
Endovascular salvage of the hypogastric artery using iliac branch device (IBD) during endovascular aortic aneurysm repair (EVAR), offers less invasive alternative solution to surgery to prevent pelvic ischemia. We have performed the first Korean surgeon custom-made IBD for this purpose to overcome the limitation of unavailability of the devices in Korea. Four patients with abdominal aortic aneurysm with bilateral common iliac artery aneurysm (CIAA) were treated using custom-made IBDs from October 2013 to December 2013. IBD was created in back table before EVAR operation using TFLE Zenith iliac limb stent graft (Cook Inc.). Three V12 (Atrium, Inc.) one Viabahn (Gore, Inc.) were used for bridging between IBD and target hypogastric artery. With this modification of IBD procedure, exteriorize the guide wire without snare device is possible which offers another benefit in terms of reducing medical costs comparing to commercial IBD. All operations were successful without any device related complications or postoperative endoleaks. During the mean follow up of 3 months, all IBD were patent without clinical complications. Surgeon custom made IBD is feasible and useful to preserve pelvic perfusion especially in the situation of limited commercial IBD availability in many countries. Long-term follow-up is needed to evaluate stent graft patency and IBD-related complications.
Subject(s)
Aged , Female , Humans , Male , Aortic Aneurysm, Abdominal/surgery , Blood Vessel Prosthesis , Endovascular Procedures/instrumentation , Equipment Design , Equipment Failure Analysis , Iliac Aneurysm/surgery , Iliac Artery/surgery , Salvage Therapy/instrumentation , StentsABSTRACT
A rubber tip disconnection of Arrow-Trerotola percutaneous thrombolytic device (PTD) may occur occasionally. We experienced 5 cases of a rubber tip disconnection among 453 mechanical thrombectomy sessions with the use of PTD. We present a report about these five cases and suggest possible causes for the occurrences.