31 |
Confiabilidade das determinaÃÃes de localizadores eletrÃnicos foraminais: estudos ex vivo e in vivo / Determination of the reliability of electronic foramen locators: ex vivo and in vivo studiesBruno Carvalho de Vasconcelos 23 September 2011 (has links)
nÃo hà / Os localizadores eletrÃnicos foraminais (LEFs) disponÃveis atualmente utilizam diversos mÃtodos de determinaÃÃo eletrÃnica da posiÃÃo foraminal, qual seja a medida entre o forame apical e uma referÃncia incisal/oclusal, definindo consequentemente o comprimento do canal radicular. Cada um desses mÃtodos procura oferecer maior precisÃo e menor sensibilidade a possÃveis interferÃncias no sistema de canais radiculares. Desta forma, procurou-se avaliar a precisÃo de alguns destes LEFs ex vivo e in vivo na realizaÃÃo de odontometrias eletrÃnicas em diferentes posiÃÃes (0,0 mm e -1,0 mm) e em condiÃÃes de uso clÃnico, respectivamente. No estudo ex vivo, 42 prÃ-molares inferiores tiveram seus comprimentos reais comparados a odontometrias eletrÃnicas realizadas com os LEFs Root ZX, Mini Apex Locator, Propex II, iPex e RomiApex A-15. Inicialmente, em funÃÃo dos displays dos aparelhos, determinaram-se mediÃÃes 1,0 mm aquÃm do forame apical (FA), e posteriormente as mediÃÃes no FA. Para o estudo in vivo, dez pacientes que apresentavam prÃ-molares com indicaÃÃo de exodontia como parte de seus planejamentos clÃnicos ortodÃnticos tiveram odontometrias eletrÃnicas realizadas com os LEFs Propex II e Root ZX previamente a exodontia. Os Ãltimos instrumentos utilizados foram fixados aos dentes que foram entÃo extraÃdos e tiveram 4,0 mm apicais de suas raÃzes expostos e analisados quanto à distÃncia entre as pontas dos instrumentos e os FA. No estudo ex vivo, considerando as mediÃÃes realizadas por cada um dos aparelhos a 0,0 mm e a -1,0 mm, a precisÃo dos LEFs foi: 70,6% e 47,1% (Root ZX), 61,8% e 52,9% (Mini Apex Locator), e 67,6% e 38,2% (Propex II), 61,8% e 38,2% (iPex), e 73,5% e 38,2% (RomiApex A-15), respectivamente (Â0,5 mm). DiferenÃas estatÃsticas foram encontradas para o Propex II, iPex e RomiApex A-15, quando comparadas suas leituras nas duas posiÃÃes (0,0mm X -1,0 mm). NÃo foram encontradas diferenÃas entre os LEFs a 0,0 mm, porÃm, a -1,0 mm o iPex foi estatisticamente inferior aos demais. Jà no estudo in vivo, o FA foi localizado em 75% (Root ZX) e 66,7% (Propex II), considerando margem de Â0,5 mm, tendo sido encontrada diferenÃa estatisticamente significante entre os LEFs. Diante do exposto, nas condiÃÃes do estudo, pode-se concluir que os LEFs sÃo ferramentas confiÃveis na determinaÃÃo de comprimentos reais, todavia, nÃo sÃo infalÃveis; que em condiÃÃes ex vivo, quando mantidos aquÃm do FA, todos os LEFs reduziram sua precisÃo, tendo o Propex II, iPex e RomiApex A-15 apresentado diferenÃas significantes; e que em condiÃÃes de uso clÃnico, o Root ZX apresentou maior confiabilidade do que o Propex II. / The electronic foramen locators (EFLs) currently available are based on different methods for determination of the distance between the apical foramen and a coronal reference, consequently presenting the real root canal length. Each of these methods aim to offer greater precision while presenting lower sensitivity to potential interferences found in the root canal system. With this in mind, the goal of this work was to evaluate the precision of some of these EFLs ex vivo and in vivo for electronic measurement of the root canal length at two different positions (0.0 mm and -1.0 mm) and under clinical conditions, respectively. In the ex vivo study, 42 mandibular bicuspids had their actual lengths compared to electronic measurements performed by the following EFLs: Root ZX, Mini Apex Locator, Propex II, iPex, and RomiApex A-15. Initial measurements were performed to positions identified by the devices as 1.0 mm short of the apical foramen (AF), and subsequent measurements were at the AF (0.0 mm). For the in vivo study, ten patients with bicuspids referred for extraction as part of their orthodontic clinical planning had electronic root length measurements using two EFLs, Propex II and Root ZX, prior to extraction. The last files used were fixated to the teeth, which were then extracted. Then, the apical 4 mm of the canals were exposed to allow assessment of the distance between the tip of the file and the AF. The percentages of precision from the ex vivo electronic measurements at 0.0 mm and -1.0 mm considering each device were: 70.6% and 47.1% (Root ZX); 61.8% and 52.9% (Mini Apex Locator); 67.6% and 38.2% (Propex II); 61.8% and 38.2% (iPex); and 73.5% and 38.2% (RomiApex A-15), respectively (Â0.5 mm). Statistical differences were observed for Propex II, iPex, and RomiApex A-15 when measurements at both positions were compared (0.0 mm X -1.0 mm). No significant differences between the EFLs were observed at 0. 0 mm. However, at -1.0 mm, the precision of iPex was statistically lower compared with the other devices. Regarding the in vivo study, the AF was located in 75% (Root ZX) and 66.7% of the teeth (Propex II), under a tolerance margin of Â0.5 mm. Statistically significant differences were observed between the two EFLs. Based on the results obtained and considering the conditions of this work, it was concluded that EFLs are reliable tools for determining the real length of the canal, but are not infallible. It was also observed in the ex vivo experiments that all EFLs had decreased precision in measurements with the instruments short of the AF, with significant differences observed between Propex II, iPex, and RomiApex A-15. Moreover, it was concluded that under clinical conditions, Root ZX was more reliable than Propex II.
|
32 |
Análise ex vivo de cortes apicais de dentes humanos em 3D empregando microtomografia computadorizada / Ex vivo analysis of apical human tooth in 3D sections using computed micro-CTMarcia Regina Ramalho da Silva Bardauil 08 July 2010 (has links)
O objetivo deste estudo in vivo foi investigar as imagens obtidas por microtomografia computadorizada (micro-TC) no estudo da anatomia apical de dentes humanos portadores de polpa viva e mortificada. Trinta e cinco dentes humanos unirradiculares ou multirradiculares que tiveram suas raízes separadas totalizando quarenta e uma raízes foram rigorosamente pré-selecionadas e divididas em dois grupos: com polpa viva (PV) n = 21 e com polpa mortificada (PM) n = 20. Os dentes de ambos os grupos foram escaneados pelo sistema de microtomografia computadorizada (SkyScan 1172) com resolução de 6,7m e suas imagens reconstruídas para a análise da região apical nos cortes sagital e coronal. O diâmetro do forame apical (FA) e da junção cemento-dentina (JCD) foram medidos bem como suas distâncias (extensão do cemento) em ambos os lados da raiz. Posteriormente a coroa dos dentes foi cortada no seu colo anatômico e suas raízes foram medidas com paquímetro eletrônico e a odontometria realizada com localizador eletrônico apical (RomiApex A15). A subtração desses dois dados foi correlacionada com as medidas obtidas pela micro-TC na avaliação da posição da JCD. As raízes foram preparadas para avaliação histológica em cortes longitudinais de 6m de espessura e corados com HE. Os cortes que apresentaram a emergência do FA foram fotografados digitalmente e as imagens correspondentes de micro-TC foram sobrepostas com o intuito de ilustrar a metodologia utilizada. As medidas da micro-TC foram realizadas por dois examinadores devidamente instruídos. A concordância inter-examinadores foi confirmada pelo coeficiente de correlação intraclasse (ICC) e as medidas foram comparadas pelo teste de Mann-Whitney (teste de Wilcoxon rank sum - p0,05). Os resultados indicaram que não houve diferença estatisticamente significante quanto à extensão do cemento intrarradicular nos grupos quer de polpa viva como mortificada com distâncias de 0,32±0,1mm e 0,36±0,16mm respectivamente. As medidas realizadas pelo localizador apical, a 1,0mm aquém, garantiu o estabelecimento do limite dentro do canal dentinário. Os resultados encontrados para o diâmetro do forame apical foi 619,32±32 m para o grupo PV e 630,542±140,99m para o grupo PM sem diferença estatisticamente significante. O diâmetro do canal radicular na junção cemento-dentina não apresentou diferença estatisticamente significante entre PV com 330,37±126,62m e PM com 357,62±996,14m. O posicionamento da JCD em relação ao FM não foi influenciado pelo estado de vitalidade pulpar. / This ex vivo study aimed to investigate the apical anatomy of vital and necrotic human roots by microcomputed tomography (micro-CT). Thirty-five single or multirooted human teeth that had their roots separated totaling forty-one roots were carefully pre-selected and divided into two groups: vital pulp (VP) n = 21 and necrotic pulp (NP) n = 20. Both groups were scanned by microcomputed tomography system (SkyScan 1172) with 6.7m resolution and the apical region was analyzed by reconstructed images in sagittal and coronal sections. The diameters of the apical foramen (AF) and root canal at the cemento-dentino canal junction (CDJ) were measured. The cementum extension into the root canal was measured on both sides of the root canal. Thereafter the teeth crown was cut at the cemento-enamel junction, the length of roots was measured with a caliper and the working length was performed by an electronic apex locator (RomiApex A15). The result of the subtraction of these two data was correlated with measures obtained by micro-CT in the evaluation of CDJ position. The roots were sectioned in longitudinal histological sections of 6m thickness and stained with HE. The sections that showed the emergence of the FA were digitally photographed and the corresponding micro-CT sections were correlated by superimposition in order to illustrate the methodology. Measures of micro-CT scans were performed by two calibrated examiners. The interexaminers agreement was confirmed by intraclass correlation coefficient (ICC) and measurements were compared by Mann-Whitney test (Wilcoxon rank sum test - p0.05). The results indicated that there was no statistically significant difference in relation to the extension of cementum into the root canal in both goups VP or NP with average distances of 0.32±0.1mm and 0.36±0.16mm respectively. The measurements taken by the apex locator 1 mm from the apex were within the limits of dentinal canal. The diameter of the apical foramen corresponded to the NP group was 619.32±201.61m and 619.32±140.99m on average, not statistically significant. The average diameter of the root at the CDJ was 330.37±126.62m for VP and 357.62 ±96.14m for NP groups presenting no statistically significant difference. The distance of the CDJ in relation to AF was not influenced by the pulp vitality.
|
33 |
Evaluation of traumatized immature teeth treated with two pulp revascularization proposals = Avaliação de dentes traumatizados com rizogênese incompleta submetidos a duas propostas de revascularização pulpar / Avaliação de dentes traumatizados com rizogênese incompleta submetidos a duas propostas de revascularização pulparNagata, Juliana Yuri, 1986- 06 October 2013 (has links)
Orientadores: Adriana de Jesus Soares, Brenda Paula Figueiredo de Almeida Gomes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T21:23:22Z (GMT). No. of bitstreams: 1
Nagata_JulianaYuri_D.pdf: 1885757 bytes, checksum: 6a26b8beb223d63399f25d6cc087da55 (MD5)
Previous issue date: 2013 / Resumo: O presente trabalho teve como objetivos: avaliar os resultados clínicos e radiográficos da utilização da pasta tripla antibiótica e do hidróxido de cálcio associado à clorexidina gel 2% para a revascularização pulpar (capítulo 1); avaliar a redução microbiana da descontaminação realizada com pasta tripla antibiótica e à base de hidróxido de cálcio e clorexidina gel 2% na revascularização pulpar, e identificar espécies microbianas por Reação em Cadeia da Polimerase (PCR) (capítulo 2); relatar dois casos clínicos de dentes reimplantados com rizogênese incompleta onde foi proposto o protocolo de revascularização pulpar (capítulo 3). Material e Métodos: Treze pacientes (7-17 anos de idade) com incisivos superiores necrosados devido a trauma dental foram divididos em dois grupos: grupo medicado com pasta tripla antibiótica (TAP) (n=7) e grupo medicado com a associação de hidróxido de cálcio e clorexidina gel 2% (CHP) (n=6). Os pacientes foram acompanhados por um período de 9 a 19 meses com avaliação dos dados clínicos e radiográficos (capítulo 1). Quinze pacientes (7-17 anos de idade) apresentando dentes imaturos foram tratados com revascularização pulpar e divididos em grupo TAP (n=7) e grupo CHP (n=8). As amostras microbianas foram coletadas inicialmente e após cada etapa de descontaminação dos canais radiculares. As bactérias cultiváveis foram contadas e identificadas por meio de PCR (capítulo 2). Dois pacientes (7 e 8 anos) foram acometidos por avulsão dentária no incisivo central superior esquerdo e no incisivo lateral superior esquerdo, respectivamente. Os dentes foram submetidos à revascularização pulpar consistindo de descontaminação passiva (hipoclorito de sódio 6%, solução fisiológica e clorexidina 2%), e medicação intracanal (hidróxido de cálcio e clorexidina gel 2%) por 21 dias. Na segunda sessão, a formação de coágulo sanguíneo foi estimulada e uma barreira de Agregado Trióxido Mineral (MTA) foi inserida (capítulo 3). Resultados: No capítulo 1, os dois grupos demonstraram completa redução da sintomatologia clínica, entretanto, escurecimento coronário foi observado em 6(85.71%) dentes do grupo TAP. Radiograficamente, todos os dentes do grupo TAP demonstraram reparo de lesão periapical, e apenas um dente do grupo CHP não demonstrou reparo periapical. Fechamento apical foi observado em 5(71,42%) dentes do grupo TAP e em 4(66.67%) dentes do grupo CHP. No capítulo 2, ambos os grupos apresentaram redução na contagem microbiana (UFC/mL) significativa entre a amostra inicial e após irrigação com NaOCl 6% (p<0.05). A utilização das medicações intracanais (grupos TAP ou CHP) não diferiu com relação às contagens de CFU/mL (p=0.95). A espécie bacteriana mais prevalente foi Actinomyces naeslundii (66,67%). Uma média de 2,13 espécies por canal foi encontrada. No capítulo 3, o primeiro caso apresentou fechamento apical e calcificação do terço apical do espaço do canal radicular no controle de 16 meses. O segundo caso demonstrou reabsorção radicular progressiva, sendo tratado com apicificação. Conclusões: A revascularização pulpar pode ser uma alternativa de tratamento para dentes acometidos por luxações traumáticas leves com rizogênese incompleta. Tanto a pasta tripla antibiótica quanto o hidróxido de cálcio associado a clorexidina gel 2% sugerem redução de sinais clínicos, radiográficos e redução microbiana na revascularização pulpar / Abstract: This study aims to: evaluate clinical and radiographic outcomes of the use of triple antibiotic paste and calcium hydroxide associated to 2% chlorhexidine gel paste for pulp revascularization therapy (chapter 1); evaluate microbial reduction of pulp revascularization performed with triple antibiotic paste and calcium hydroxide associated to 2% chlorhexidine gel, and identify bacteria species using Polymerase Chain Reaction (PCR) (chapter 2); report two clinical cases of immature replanted teeth which were treated with a protocol of pulp revascularization (chapter 3). Methods: Thirteen patients (7-17 years-old) with necrotic upper incisors due to dental trauma were divided in two groups: group treated with triple antibiotic paste (TAP) (n=7) and group dressed with the association of calcium hydroxide and 2% chlorhexidine gel (CHP) (n=6). Patients were followed-up for till 9 to 19 months, with evaluation of clinical and radiographic data (chapter 1). Fifteen patients (7-17 years-old) presenting immature teeth were treated with revascularization and divided in group TAP (n=7) and group CHP (n=8). Samples were taken initially and after each step of root canal decontamination. Cultivable bacteria recovered at the five stages were counted and identified by means of PCR assay (chapter 2). Two patients (7 and 8 years old) suffered tooth avulsion on maxillary left lateral incisor and on maxillary left central incisor, respectively. Treatment consisted of revascularization therapy using passive decontamination (6% sodium hypochlorite, 2% chlorhexidine and sterile saline) and intracanal medication (calcium hydroxide and 2% chlorhexidine gel) for 21 days. In the second session, blood clot was stimulated and Aggregate Trioxide Mineral was used as a cervical barrier of the canal (chapter 3). Results: In chapter 1, clinical evaluation in both groups (TAP and CHP) observed that there was complete reduction concerning clinical symptomatology, however, crown discoloration was observed in 6(85.71%) teeth of group TAP. In radiographic exam, all teeth of group TAP showed repair of periapical lesions, and only one tooth of group CHP did not show apical repair. Apical closure was observed in 5(71.42%) teeth of group TAP and in 4(66.67%) teeth of group CHP. In chapter 2, both groups presented bacteria counts (CFU/mL) decreasing significantly after irrigation with 6% NaOCl (p<0.05). Intracanal dressing did not differ in relation to CFU counts (p=0.95). The most prevalent bacteria identified were Actinomyces naeslundii (66.67%). An average of 2.13 species per canal was found. In chapter 3, it was observed apical closure and calcification in the apical third of root canal space at the 16-month follow-up. The second case presented progressive root resorption, being treated with apexification. Conclusions: Pulp revascularization may be an alternative of treatment for mild luxated traumatized immature teeth. Both triple antibiotic paste and calcium hydroxide associated to 2% chlorhexidine gel paste may be employed in pulp revascularization suggesting clinical, radiographic and microbial reduction after their use / Doutorado / Endodontia / Doutora em Clínica Odontológica
|
34 |
Factors Influencing Movements and Foraging Ecology of American Alligators (Alligator mississippiensis) in a Dynamic Subtropical Coastal EcosystemRosenblatt, Adam 14 June 2013 (has links)
Top predators can have large effects on community and population dynamics but we still know relatively little about their roles in ecosystems and which biotic and abiotic factors potentially affect their behavioral patterns. Understanding the roles played by top predators is a pressing issue because many top predator populations around the world are declining rapidly yet we do not fully understand what the consequences of their potential extirpation could be for ecosystem structure and function. In addition, individual behavioral specialization is commonplace across many taxa, but studies of its prevalence, causes, and consequences in top predator populations are lacking. In this dissertation I investigated the movement, feeding patterns, and drivers and implications of individual specialization in an American alligator (Alligator mississippiensis) population inhabiting a dynamic subtropical estuary. I found that alligator movement and feeding behaviors in this population were largely regulated by a combination of biotic and abiotic factors that varied seasonally. I also found that the population consisted of individuals that displayed an extremely wide range of movement and feeding behaviors, indicating that individual specialization is potentially an important determinant of the varied roles of alligators in ecosystems. Ultimately, I found that assuming top predator populations consist of individuals that all behave in similar ways in terms of their feeding, movements, and potential roles in ecosystems is likely incorrect. As climate change and ecosystem restoration and conservation activities continue to affect top predator populations worldwide, individuals will likely respond in different and possibly unexpected ways.
|
35 |
Proximity and Affinity based Analysis of Cardiac Caveolin Protein InteractionsPeper, Jonas 26 February 2020 (has links)
No description available.
|
36 |
Takotsubo Cardiomyopathy Mimicking Stent Thrombosis After Percutaneous Coronary InterventionKhattak, Furqan, Khalid, Muhammad, Murtaza, Ghulam, Paul, Timir K. 30 April 2018 (has links)
Takotsubo cardiomyopathy, also known as “broken heart syndrome,” is a transient left ventricular dysfunction associated with stress (usually emotional) induced myocardial injury and stunning. It often presents as myocardial infarction on surface electrocardiogram (EKG). Diagnosis is made by coronary angiography, which rules out coronary artery disease and shows pathognomonic apical ballooning. In this article, we present a case of a 72-year-old woman who initially presented with an ST segment elevation myocardial infarction on EKG. Coronary angiography showed severe left anterior descending artery and diagonal lesions requiring percutaneous coronary intervention. Post–percutaneous coronary intervention, EKG changes resolved. The next day, the patient developed recurrent chest pain and her EKG showed diffuse T-wave inversion in precordial leads with reemerging ST segment elevations concerning for stent thrombosis. The patient underwent repeat emergent coronary angiography, which showed patent stents and findings consistent with takotsubo cardiomyopathy.
|
37 |
Comparison of guided endodontic access with and without pin fixation in 3D printed teeth with simulated pulp canal obliterationLong, Jacob Daniel 06 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: In order to successfully treat an infected root canal system (RCS), it is required to locate all root canals and have an access path to the apex of each canal. This can be challenging in teeth with pulp canal obliteration (PCO), often leading to increased chair time and increased risk of iatrogenic errors. Guided endodontic access (GEA) combines information from a cone-beam computed tomography (CBCT) scan with an intra-oral scan to create a stent. GEA stents with or without fixation pins have been shown to be successful in accurately negotiating a RCS with PCO.
Objective: Compare the degree of deviation and difference in 3D offset at the base to apical tip of the drill from the designed access path when a GEA stent with and without pin fixation is used to access tooth #8 with PCO.
Materials and Methods: A 3-D printed maxillary model of an anonymous patient had a GEA stent designed using coDiagnonstiX software. The stent extended from tooth #3 to tooth #14 with the guide sleeve over tooth #8. Tooth #8 with no calcification, calcification to the cervical third, and calcification to the middle third of the RCS were designed in the coDiagnostiX software. Tooth #8 will be accessed using a 1.3 mm drill that fits a 1.3 mm sleeve used for both access and pin fixation. 15 of the 30 GEA samples will utilized pin fixation, while the other 15 samples did not utilize pin fixation. Following GEA in all 30 samples a CBCT was taken of each sample. Each post-operative CBCT was aligned with the pre-operative CBCT in the coDiagnostiX software. The coDiagnostiX software was able to calculate the degree of deviation and difference in 3D offset between the base and apical tip of the drill during GEA. Paired t-tests were used to test each group for significant differences in 3D offset between base and tip. Two-way ANOVA was used to evaluate the effects of pin fixation and calcification on the degree of deviation and the deviation of 3D offset of the entry point and tip.
Results: There was a significant interaction between use of pin fixation and calcification level on the degree of deviation of GEA. GEA with pin fixation had a significantly larger degree of deviation than GEA without pin fixation with calcification extending to the middle third of the RCS. GEA with and without pin fixation did not have a significant difference when calcification extended to the cervical third of the RCS or no calcification was present. There was a significant interaction between use of pin fixation and calcification level on 3D offset difference. GEA with pin fixation had a significantly larger 3D offset difference than GEA with no pin fixation for calcification in the middle third of the RCS. For GEA with and without pin fixation there was no significant difference when calcification extended to the cervical third of the RCS or no calcification was present.
Conclusion: The use of pin fixation did not result in a decrease of degree of deviation or difference in 3D offset during GEA access. It can be concluded that the use of pin fixation is not necessary for GEA of teeth with PCO when a full dentition is present to provide stability and retention of the stent. / 2022-06-21
|
38 |
How does urbanisation affect the breeding performance of African Crowned Eagles (Stephanoaetus coronatus)?Muller, Rebecca 03 February 2020 (has links)
Birds face many challenges from the process of urbanisation. Those species that are able to occupy urban areas offer opportunities to understand processes of acclimatisation to urban life and may help in the development of urban spaces for the benefit of wildlife. In many bird species, individuals that occupy territories in more urban areas show lower productivity and lower body condition of nestlings, which is thought to be mediated by food availability. Most of the studies exploring this issue were done on passerines and carried out in the global north, with very few studies exploring this topic on non-passerines, and even fewer in Africa. Studies addressing urban productivity in apex predators with slow life histories that are often of conservation concern are largely missing. Here, we explore the breeding performance of the African Crowned Eagles (Stephanoaetus coronatus) across an urbanisation gradient in KwaZuluNatal, South Africa. Specifically, we explored the hypothesis that living in an urban environment allows this species, which is typically a biennial breeder, to breed annually more often (i.e. increased breeding rate), and whether this might increase the productivity of this species. We also explore whether there may be any hidden costs of such a breeding strategy by examining the condition of chicks for pairs which had successfully bred in the previous year. We found that Crowned Eagles breeding in more urban areas attempted to breed more often (i.e., higher breeding rate), but that these birds also suffered from lower breeding success. These two contrasting responses counteracted each other and meant that overall productivity (number of young produced per occupied territory) was not influenced by urbanisation. Breeding annually did not appear to have a negative cost on the chick condition, as offspring in the year following a successful breeding attempt did not have lowered body condition. This species appears to be well adjusted to breeding in an urban environment. Crowned Eagles are currently considered vulnerable in South Africa, and ensuring that an urban population of this species is able to persist can help secure the conservation status of this charismatic species.
|
39 |
AN IN VITRO EVALUATION OF THE WIRELE-X ELECTRONIC APEX LOCATORBrand, Lucas M, DDS, Dunlap, Craig A, DDS, Scott, Ray, DDS MSD, Peters, Ove A, DMD MS PhD 01 January 2021 (has links)
Aim: The aim of this study was to evaluate the accuracy of the Wirele-X (Forum Tec, Ashkelon, Israel), a new Bluetooth-enabled electronic apex locator (EAL). The accuracy of the Wirele-X and the Root ZX II (J. Morita, Tokyo, Japan) was compared in vitro using an alginate model. Materials/Methods: Thirty-one extracted single-rooted human teeth with mature apices were decoronated at the CEJ. Under 10X magnification, actual canal lengths (ACL) were determined. The teeth were embedded in alginate and electronic canal length measurements were obtained using the Root ZX II and Wirele-X EALs. Each tooth was measured three times with both EALs. A blinded examiner measured each file with a digital micrometer to the nearest 0.01 mm. Differences between ACLs and the average measurements from the EALs were compared with Student's t test for related samples. Results: The average distance from the file tip to the apical foramen (AF) was -0.11 mm (±0.16) and -0.07 mm (±0.21) for the Root ZX II and Wirele-X systems, respectively. There were no statistically significant differences between the two apex locators in their ability to locate the AF (p > 0.05). Conclusions: Both the Wirele-X and the Root ZX II provided a high level of accuracy and reliability in locating the AF.
|
40 |
Dynamic Analysis of a Window connected via the Click-In SystemBhatia, Abhikaran January 2022 (has links)
It is often needed to predict the behavior of structures. With the helpof an FE model, it is possible to see the motion of the structure. Inthis, Master thesis work time domain analyses were carried out on afinite element model representing a window attached by click-ins. Theaim was to establish an FE model which gives a good correlation withtest data. The finite element modelling was carried out in MSC Apex.MSC Nastran was utilised to analyze the FEA model and the resultwas post-processed in Simxpert. Different vibrational tests were made. A crane was used to exciteand support the wall together with the window and the responseswere recorded with tri-axial accelerometers. During the thesis, it wasfound that the FE model requires more work and accurate boundaryconditions to provide better resemblance with the test data.The results deviate from the measured. This opens future possibilities tocarry on the project.
|
Page generated in 0.1717 seconds