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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Direct-sequence spread spectrum system designs for future aviation data links using spectral overlay

Neville, Joshua T. January 2004 (has links)
Thesis (M.S.)--Ohio University, June, 2004. / Title from PDF t.p. Includes bibliographical references (leaves 96-97).
12

Pilot estimates of glide path and aim point during simulated landing approaches

Acree, Cecil Wallace January 1978 (has links)
Thesis. 1978. E.A.A.--Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND AERONAUTICS. / Bibliography: leaves 130-133. / by C.W. Acree, Jr. / E.A.A.
13

Adaptive glide slope control for parafoil and payload aircraft

Ward, Michael 21 May 2012 (has links)
Airdrop systems provide a unique capability of delivering large payloads to undeveloped and inaccessible locations. Traditionally, these systems have been unguided, requiring large landing zones and drops from low altitude. The invention of the steerable, gliding, ram-air parafoil enabled the possibility of precision aerial payload delivery. In practice, the gliding ability of the ram-air parafoil can actually create major problems for airdrop systems by making them more susceptible to winds and allowing them to achieve far greater miss distances than were previously possible. Research and development work on guided airdrop systems has focused primarily on evolutionary improvements to the guidance algorithm, while the navigation and control algorithms have changed little since the initial autnomous systems were developed. Furthermore, the control mechanisms have not changed since the invention of the ram-air canopy in the 1960's. The primary contributions of this dissertation are: 1) the development of a reliable and robust method to identify a flight dynamic model for a parafoil and payload aircraft using minimal sensor data; 2) the first demonstration in flight test of the ability to achieve large changes in glide slope over ground using coupled incidence angle variation and trailing edge brake deflection; 3) the first development of a control law to implement glide slope control on an autonomous system; 4) the first flight tests of autonomous landing with a glide slope control mechanism demonstrating an improvement in landing accuracy by a factor of 2 or more in especially windy conditions, and 5) the first demonstrations in both simulation and flight test of the ability to perform in-flight system identification to adapt the internal control mappings to flight data and provide dramatic improvements in landing accuracy when there is a significant discrepancy between the assumed and actual flight characteristics.
14

En route speed optimization for continuous descent arrival

Lowther, Marcus Benjamin 01 April 2008 (has links)
Continuous Descent Arrival (CDA) procedures have been shown to minimize the thrust required during landing, thereby reducing noise, emissions, and fuel usage for commercial aircraft. Thus, implementation of CDA at Atlanta's Hartsfield-Jackson International Airport, the world's busiest airport, would result in significant reductions in environmental impact and airline operating costs. The Air Transportation Laboratory at Georgia Tech, Delta Air Lines, and the local FAA facilities (Atlanta Center and Atlanta TRACON) collaborated to design CDA procedures for early morning arrivals from the west coast. Using the Tool for Analysis of Separation and Throughput (TASAT), we analyzed the performance of various aircraft types over a wide range of weights and wind conditions to determine the optimum descent profile parameters and to find the required spacing between aircraft types at a fixed metering point to implement the procedure. However, to see the full benefits of CDA, these spacing targets must be adhered, lest there will be a loss in capacity or negation of the noise, emissions, and fuel savings benefits. Thus a method was developed to determine adjustments to cruise speeds while aircraft are still en route, to achieve these spacing targets and to optimize fleet wide fuel burn increase. The tool in development, En route Speed Change Optimization Relay Tool (ESCORT), has been shown to solve the speed change problem quickly, incorporating aircraft fuel burn information and dividing the speed changes fairly across multiple airlines. The details of this tool will be explained in this thesis defense. Flight tests were conducted in April-May of 2007, where it was observed that the spacing targets developed by TASAT were accurate but that delivery of these aircraft to the metering point with the desired spacing targets was very challenging without automation. Thus, further flight tests will be conducted in 2008 using the en route spacing tool described above to validate the improvement it provides in terms of accurately delivering aircraft to the metering point.
15

Influência de diferentes instrumentos de patência no transporte e centralização do forame apical : análise em microtomografia computadorizada

Rotta, Eduardo Ourique January 2018 (has links)
A dificuldade de realizar a patência apical, tendo em vista que os canais radiculares apresentam algum grau de curvatura, exigiu o desenvolvimento de instrumentos rotatórios para agilizar o tempo operatório e facilitar sua execução. O objetivo deste estudo foi avaliar a influência de diferentes instrumentos de patência, utilizados 1 mm além do forame apical, no tempo de ação, transporte e centralização do canal radicular de canais radiculares curvos. Trinta e três raízes mesiais de molares superiores com curvatura entre 20 e 40 graus e raio menor que 10 mm foram selecionadas e divididas em 3 grupos (n = 11): R-Pilot #12.5 taper 0.04 (VDW, Munich, Alemanha), ProDesign Logic #25 taper 0.01 (Easy Equipamentos Odontologicos, Belo Horizonte, Brasil) e ProGlider #16 e taper variável de 0.02 a 0.08 (Dentsply Maillefer, Ballaigues, Suiça). Através de imagens pré e pós-operatórias de microtomografia computadorizada foram feitas as análises de transporte e centralização do canal radicular. Ainda, o tempo de ação de cada um dos instrumentos foi cronometrado. Para avaliar o transporte, foi utilizado o teste ANOVA. Para avaliar a centralização foi utilizado o teste Kruskal-Wallis. O tempo de ação foi avaliado pelo teste de Kruskal-Wallis e Post hoc de Dunn. O nível de significância foi de 5% para todos os testes aplicados. Não houve diferença estatística entre os grupos nas análises de transporte e centralização. Já na análise de tempo, o instrumento ProGlider se mostrou significativamente mais rápido se comparado com o ProDesign Logic 25.01 (P<0,05), o instrumento R-Pilot não foi diferente do ProGlider e Logic (p>0,05). Os instrumentos de patência utilizados neste estudo, e trabalhados 1 mm além do forame apical, permaneceram relativamente centralizadas dentro do canal radicular e promoveram transporte apical mínimo, sendo clinicamente irrelevante. / The difficulty of performing the apical patency, considering that the root canals present some degree of curvature, required the development of rotary instruments to speed up the operative time and facilitate its execution. The aim of this study was to evaluate the influence of different glide path files, used 1 mm beyond the apical foramen, on the preparation time, apical transportation and centering of the root canal of curved roots. Thirty three mesiobuccal roots from maxillary molars, with 20 to 40 degrees of curvature and presenting radio curvature lower than 10 mm were selected and divided in 3 groups (n = 11): R-Pilot #12.5 taper 0.04 (VDW, Munich, Germany), ProDesign Logic #25 taper 0.01 (Easy Equipamentos Odontologicos, Belo Horizonte, Brazil) ProGlider #16 e taper variable of 0.02 to 0.08 (Dentsply Maillefer, Ballaigues, Switzerland). Analysis of transportation and centration of root canal was performed using pre and postoperative computerized microtomography images and the work time of each file was measured. To evaluate the apical transportation, ANOVA test was used, while a Kruskal-Wallis test was used to assess centering ability. As for action time, Kruskal-Wallis and Dunn tests were performed. The level of significance was 5 % in all tests. No statistical difference was found amongst the groups for the variables apical transportation and centralization. When evaluated the action time, the ProGlider file has been significantly faster when compared to ProDesign Logic 25.1 (P<0.05).while R-pilot has not differed from ProGlider and Logic (P>0.05). The glide path files used – 1 mm beyond the apical foramen – remained relatively centralized inside the root canal and promoted minimal apical transportation, expressing no clinical relevance.
16

Influência de diferentes instrumentos de patência no transporte e centralização do forame apical : análise em microtomografia computadorizada

Rotta, Eduardo Ourique January 2018 (has links)
A dificuldade de realizar a patência apical, tendo em vista que os canais radiculares apresentam algum grau de curvatura, exigiu o desenvolvimento de instrumentos rotatórios para agilizar o tempo operatório e facilitar sua execução. O objetivo deste estudo foi avaliar a influência de diferentes instrumentos de patência, utilizados 1 mm além do forame apical, no tempo de ação, transporte e centralização do canal radicular de canais radiculares curvos. Trinta e três raízes mesiais de molares superiores com curvatura entre 20 e 40 graus e raio menor que 10 mm foram selecionadas e divididas em 3 grupos (n = 11): R-Pilot #12.5 taper 0.04 (VDW, Munich, Alemanha), ProDesign Logic #25 taper 0.01 (Easy Equipamentos Odontologicos, Belo Horizonte, Brasil) e ProGlider #16 e taper variável de 0.02 a 0.08 (Dentsply Maillefer, Ballaigues, Suiça). Através de imagens pré e pós-operatórias de microtomografia computadorizada foram feitas as análises de transporte e centralização do canal radicular. Ainda, o tempo de ação de cada um dos instrumentos foi cronometrado. Para avaliar o transporte, foi utilizado o teste ANOVA. Para avaliar a centralização foi utilizado o teste Kruskal-Wallis. O tempo de ação foi avaliado pelo teste de Kruskal-Wallis e Post hoc de Dunn. O nível de significância foi de 5% para todos os testes aplicados. Não houve diferença estatística entre os grupos nas análises de transporte e centralização. Já na análise de tempo, o instrumento ProGlider se mostrou significativamente mais rápido se comparado com o ProDesign Logic 25.01 (P<0,05), o instrumento R-Pilot não foi diferente do ProGlider e Logic (p>0,05). Os instrumentos de patência utilizados neste estudo, e trabalhados 1 mm além do forame apical, permaneceram relativamente centralizadas dentro do canal radicular e promoveram transporte apical mínimo, sendo clinicamente irrelevante. / The difficulty of performing the apical patency, considering that the root canals present some degree of curvature, required the development of rotary instruments to speed up the operative time and facilitate its execution. The aim of this study was to evaluate the influence of different glide path files, used 1 mm beyond the apical foramen, on the preparation time, apical transportation and centering of the root canal of curved roots. Thirty three mesiobuccal roots from maxillary molars, with 20 to 40 degrees of curvature and presenting radio curvature lower than 10 mm were selected and divided in 3 groups (n = 11): R-Pilot #12.5 taper 0.04 (VDW, Munich, Germany), ProDesign Logic #25 taper 0.01 (Easy Equipamentos Odontologicos, Belo Horizonte, Brazil) ProGlider #16 e taper variable of 0.02 to 0.08 (Dentsply Maillefer, Ballaigues, Switzerland). Analysis of transportation and centration of root canal was performed using pre and postoperative computerized microtomography images and the work time of each file was measured. To evaluate the apical transportation, ANOVA test was used, while a Kruskal-Wallis test was used to assess centering ability. As for action time, Kruskal-Wallis and Dunn tests were performed. The level of significance was 5 % in all tests. No statistical difference was found amongst the groups for the variables apical transportation and centralization. When evaluated the action time, the ProGlider file has been significantly faster when compared to ProDesign Logic 25.1 (P<0.05).while R-pilot has not differed from ProGlider and Logic (P>0.05). The glide path files used – 1 mm beyond the apical foramen – remained relatively centralized inside the root canal and promoted minimal apical transportation, expressing no clinical relevance.
17

Influência de diferentes instrumentos de patência no transporte e centralização do forame apical : análise em microtomografia computadorizada

Rotta, Eduardo Ourique January 2018 (has links)
A dificuldade de realizar a patência apical, tendo em vista que os canais radiculares apresentam algum grau de curvatura, exigiu o desenvolvimento de instrumentos rotatórios para agilizar o tempo operatório e facilitar sua execução. O objetivo deste estudo foi avaliar a influência de diferentes instrumentos de patência, utilizados 1 mm além do forame apical, no tempo de ação, transporte e centralização do canal radicular de canais radiculares curvos. Trinta e três raízes mesiais de molares superiores com curvatura entre 20 e 40 graus e raio menor que 10 mm foram selecionadas e divididas em 3 grupos (n = 11): R-Pilot #12.5 taper 0.04 (VDW, Munich, Alemanha), ProDesign Logic #25 taper 0.01 (Easy Equipamentos Odontologicos, Belo Horizonte, Brasil) e ProGlider #16 e taper variável de 0.02 a 0.08 (Dentsply Maillefer, Ballaigues, Suiça). Através de imagens pré e pós-operatórias de microtomografia computadorizada foram feitas as análises de transporte e centralização do canal radicular. Ainda, o tempo de ação de cada um dos instrumentos foi cronometrado. Para avaliar o transporte, foi utilizado o teste ANOVA. Para avaliar a centralização foi utilizado o teste Kruskal-Wallis. O tempo de ação foi avaliado pelo teste de Kruskal-Wallis e Post hoc de Dunn. O nível de significância foi de 5% para todos os testes aplicados. Não houve diferença estatística entre os grupos nas análises de transporte e centralização. Já na análise de tempo, o instrumento ProGlider se mostrou significativamente mais rápido se comparado com o ProDesign Logic 25.01 (P<0,05), o instrumento R-Pilot não foi diferente do ProGlider e Logic (p>0,05). Os instrumentos de patência utilizados neste estudo, e trabalhados 1 mm além do forame apical, permaneceram relativamente centralizadas dentro do canal radicular e promoveram transporte apical mínimo, sendo clinicamente irrelevante. / The difficulty of performing the apical patency, considering that the root canals present some degree of curvature, required the development of rotary instruments to speed up the operative time and facilitate its execution. The aim of this study was to evaluate the influence of different glide path files, used 1 mm beyond the apical foramen, on the preparation time, apical transportation and centering of the root canal of curved roots. Thirty three mesiobuccal roots from maxillary molars, with 20 to 40 degrees of curvature and presenting radio curvature lower than 10 mm were selected and divided in 3 groups (n = 11): R-Pilot #12.5 taper 0.04 (VDW, Munich, Germany), ProDesign Logic #25 taper 0.01 (Easy Equipamentos Odontologicos, Belo Horizonte, Brazil) ProGlider #16 e taper variable of 0.02 to 0.08 (Dentsply Maillefer, Ballaigues, Switzerland). Analysis of transportation and centration of root canal was performed using pre and postoperative computerized microtomography images and the work time of each file was measured. To evaluate the apical transportation, ANOVA test was used, while a Kruskal-Wallis test was used to assess centering ability. As for action time, Kruskal-Wallis and Dunn tests were performed. The level of significance was 5 % in all tests. No statistical difference was found amongst the groups for the variables apical transportation and centralization. When evaluated the action time, the ProGlider file has been significantly faster when compared to ProDesign Logic 25.1 (P<0.05).while R-pilot has not differed from ProGlider and Logic (P>0.05). The glide path files used – 1 mm beyond the apical foramen – remained relatively centralized inside the root canal and promoted minimal apical transportation, expressing no clinical relevance.
18

GBAS sistemos taikymo Lietuvos aviacijoje galimybių tyrimas / Analysis of Possibilities of GBAS System Application for Lithuanian Aviation

Ambrakaitis, Rimas 17 June 2013 (has links)
Baigiamajame magistro darbe nagrinėjamos palydovinės tikslaus tūpimo pagal prietaisus sistemos taikymo Lietuvos aviacijoje galimybės. Aptartos palydovinės navigacijos sistemos tikslumą įtakojančios paklaidos, jų šaltiniai. Nagrinėjama GBAS sistemos struktūra, veikimo principas, paklaidų eliminavimo būdai. Išnagrinėtos šios sistemos panaudojimo galimybės (infrastruktūros ir ekonominiu požiūriais) tarptautiniuose Vilniaus, Kauno, Palangos ir Šiaulių oro uostuose. Atlikti bandymai Vilniaus tarptautiniame oro uoste, įvertinant potencialias GPS paklaidas bei įvertinant GBAS sistemos tikslumo ir tinkamumo galimybes. Išnagrinėjus teorinius ir praktinius tyrimo rezultatus, pateikiamos baigiamojo darbo išvados ir siūlymai. Darbą sudaro 9 dalys: įvadas, analitinė dalis, palydovinės radijo navigacinės sistemos antžeminė patikslinimo sis-tema, diferencinės pataisos, tikslaus artėjimo tūpti GBAS sistema, tiriamoji dalis, rezultatų apibendrinimas, literatūros sąrašas, priedai. Darbo apimtis – 63 p. teksto be priedų, 40 iliustr., 11 lent., 34 bibliografiniai šaltiniai. Atskirai pridedami darbo priedai. / This master’s thesis explores possibilities of satellite precision instrument landing application for Lithuanian avia-tion. At the first part of the thesis satellite navigation errors affecting its accuracy and their sources were examined. GBAS system stricture, its operation and error elimination methods were reviewed. Further explored were possibilities of imple-menting the analyzed system (infrastructure and economic terms) in international Vilnius, Kaunas, Palanga and Šiauliai airports. Test were carried out in Vilnius international airport aiming for assessment of potential GPS signal errors and estimation of GBAS systems accuracy and fitness opportunities, followed by theoretical and practical examination of the analysis data collected. Based on the examination results final thesis conclusions and recommendations are formulated and provided at the ending of this thesis. Structure: introduction, analytical part, ground based augmentation system, diferential corrections, precision lan-ding GBAS system, exploratory part, conclusions and suggestions, references. Thesis consist of: 63 p. text without appendixes, 40 pictures, 11 tables, 34 bibliographical entries. Appendixes included.
19

The influence of glide path preparation on the failure rate of nickel-titanium reciprocating instruments

Jonker, Casper Hendrik January 2013 (has links)
Introduction: The aim of this in vitro study was to determine the influence of two glide path preparation methods on the fracture rate of the Primary 25/08 WaveOne reciprocating instrument. The number of simulator Endo-Training-Blocks in each group were calculated at the time of instrument fracture and compared to determine the influence of glide path preparation on the failure rate of the Primary 25/08 WaveOne reciprocating instrument. Preparation times for different glide path methods and total time for root canal preparation, with or without glide path, was also calculated. Materials and Methods: Simulator Endo-Training-Blocks (n = 300) were selected and randomly divided into 3 groups (n = 100). The 3 groups were then sub-divided into 5 smaller groups (n = 20). Root canal preparation was done with new primary 25/08 WaveOne instruments allocated to each group (5 in total for each group, 1 for each sub-group) following different methods for glide path preparation. Group 1: no glide path (control); Group 2: glide path preparation with stainless-steel hand files (size 10 K-File followed by size 15 K-File and finally size 20 K-File until loose fitting); and Group 3: glide path preparation with rotary PathFiles (size 10 K-File until loose fitting followed by PathFile no.1 (ISO 13 tip), PathFile no.2 (ISO 16 tip) and finally PathFile no. 3 (ISO 19 tip)). The Primary 25/08 WaveOne reciprocating instrument was used with the WaveOne endodontic motor in “WaveOne All “mode with a brushing motion on the outstroke. Simulated root canals were irrigated with sterile water and Glyde was used as lubricating agent. The outcome was measured by recording how many simulators could be prepared with one instrument before instrument breakage occurred. The preparation protocol was repeated 5 times. The time it took to prepare the glide path and the total preparation time was also calculated. The data of the different parts of the project were collected and statistically analysed using the ANOVA / Bonferroni test. Results: Glide path preparation with PathFiles was significantly faster (13.3 s ± 2.60 s) than with hand files (25.1 s ± 1.70 s) (P < 0.001). The highest number of simulators could be prepared after glide path preparation was performed with PathFiles (19.2 ± 0.84) (P < 0.001). Pairwise comparisons at the Bonferroni adjusted significance level of 0.017 demonstrated that there were statistical significant differences (P < 0.001) when PathFiles (19.2 ± 0.84) and hand files (17.6 ±1.14) were compared to the no glide path group (7.4 ± 0.89). There was no statistical significant difference between PathFiles and hand files groups. Total Preparation time was significantly shorter (P < 0.001) when an initial glide path was prepared with PathFiles (12.7 ± 0.22 s). The longest preparation time (P < 0.001) was calculated in group 1 where no glide path (21.2 ± 0.20 s) was present and the Endo-Training-Blocks were left undisturbed. Conclusion: Initial glide path preparation with PathFiles resulted in shorter preparation time (glide path and total preparation) and allowed a higher number of simulators prepared before failure of the WaveOne instrument. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Odontology / unrestricted
20

M?todos de mensura??o de curvaturas radiculares e a influ?ncia do glide path na manuten??o da centraliza??o e no transporte apical preparos endod?nticos : revis?es sistem?ticas e an?lise cr?tica

Hartmann, Rafael Chies 12 November 2018 (has links)
Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-12-12T18:58:35Z No. of bitstreams: 1 RAFAEL_CHIES_HARTMANN_TESE.pdf: 1515467 bytes, checksum: 0787dc0b8180f2af60c74c918444dab7 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-12-14T13:33:17Z (GMT) No. of bitstreams: 1 RAFAEL_CHIES_HARTMANN_TESE.pdf: 1515467 bytes, checksum: 0787dc0b8180f2af60c74c918444dab7 (MD5) / Made available in DSpace on 2018-12-14T16:01:26Z (GMT). No. of bitstreams: 1 RAFAEL_CHIES_HARTMANN_TESE.pdf: 1515467 bytes, checksum: 0787dc0b8180f2af60c74c918444dab7 (MD5) Previous issue date: 2018-11-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The great majority of the roots present curvatures and the knowledge of these curves allows the clinician a better choice for endodontic therapy. Therefore, it is necessary to use methods that can measure these curvatures with good accuracy levels. The preparation of a glide path prior to root canal instrumentation is widely suggested because can avoid possible operative errors, such as loss of centralization and apical transportation, especially in curved root canals. There is no consensus concerning the methods that can be used to measure radicular curvatures, nor regarding the efficacy of glide path. The present investigation has the objective of performing two systematic reviews in order to answer the following questions: 1- What are the methods, described in the literature, used to measure the angles and other characteristics of the curvatures of the root canals? 2- The glide path is able to reduce the apical transportation and the loss of centralization of the endodontic preparation? Also, how does the glide path - manual or engine-driven - result in minor operative errors? Methods: Using the appropriate terms for each review, electronic searches were performed on six databases: PubMed, PubMed Central (PMC), Embase, Scopus, EBSCO Dentistry & Oral Sciences Source (DOSS) and Virtual Health Library (VHL). We used studies published in English or in any language with Latin alphabet. There was no time limit for publications. In addition, in the second review, the included studies, the risk of biases was analyzed. Results: In review 1, about the methods of measurement of curvatures, 6,336 studies were obtained and of these, 31 articles that described innovative methods. Eleven studies described the methods used to measure only the angle of the radicular curvatures, for which they used 2D images. 13 studies also used 2D images, however, in addition to the angles, evaluated other features of the root canal curvatures (position, length, direction, height and shape). In addition, seven studies evaluated curvatures using 3D methods. In review 2, regarding glide path, 2,146 articles were obtained, and 18 studies fulfilled the inclusion criteria, composing the final analysis. 9 studies evaluated the glide path per se and 11 evaluated the impact of glide path on final engine-driven endodontic preparation. Conclusion: Revision 1 suggested that most methods for root canal curvature measurement have potential clinical applications; however, there is a lack of consensus on the ideal technique. In addition to the angle, other features, such as radius and position of curvature, need to be measured and should be considered when evaluating root canal curvature in both clinical and research purposes. Revision 2 revealed that engine-driven confection of glide path, when compared to manual, presents similar or better results of apical transportation and maintenance of root canal centralization. It was also observed that the preparation of glide path, prior to endodontic preparation, is associated with similar results or with a reduction of the apical transportation and the maintenance of the preparation centralization. It was also observed that deviations occur in all situations. / A grande maioria dos condutos apresenta curvaturas e o conhecimento destas curvaturas permite ao cl?nico uma melhor escolha da terap?utica endod?ntica. Para tanto, faz-se necess?rio o emprego de m?todos que possam medir essas curvaturas com bons n?veis de acur?cia. A confec??o de um glide path pr?vio ? instrumenta??o dos canais radiculares ? amplamente sugerida, pois pode evitar poss?veis erros operat?rios, tais como a perda de centraliza??o do preparo e o transporte apical, especialmente em canais radiculares curvos. Como n?o h? consenso quanto aos m?todos que podem ser utilizados na medi??o das curvaturas radiculares, tampouco referente a efic?cia do glide path, a presente investiga??o tem o objetivo de realizar duas revis?es sistem?ticas, a fim de responder ?s seguintes quest?es: 1- Quais s?o os m?todos, descritos na literatura, empregados na mensura??o dos ?ngulos e demais caracter?sticas das curvaturas dos canais radiculares? 2- O glide path ? capaz de reduzir o transporte apical e a perda de centraliza??o do preparo endod?ntico? Al?m disso, qual a forma de confec??o do glide path ? manual ou motorizada ? resulta em menores erros operat?rios? M?todos: Utilizando os termos apropriados para cada revis?o, foram realizadas buscas eletr?nicas em seis bases de dados: PubMed, PubMed Central (PMC), Embase, Scopus, EBSCO Dentistry & Oral Sciences Source (DOSS) e Virtual Health Library (VHL). Foram utilizados estudos publicados em ingl?s ou em qualquer idioma com alfabeto latino n?o houve qualquer limite temporal para as publica??es. Al?m disso, na segunda revis?o, os estudos inclu?dos tiveram o risco de vieses analisado. Resultados: Na revis?o 1, acerca dos m?todos de mensura??o das curvaturas, foram obtidos 6.346 estudos e destes, restaram 31 artigos que descreviam m?todos inovadores. Onze estudos foram descritos a fim de mensurar apenas o ?ngulo das curvaturas radiculares, para isso utilizaram 9 imagens em 2D. 13 estudos utilizaram tamb?m imagens em 2D, entretanto, al?m dos ?ngulos avaliaram outras caracter?sticas das curvaturas dos canais radiculares (posi??o, comprimento, dire??o, altura e forma). Al?m disso, sete estudos avaliaram as curvaturas atrav?s de m?todos em 3D. J? na revis?o 2, a respeito do glide path, obteve-se 2.146 artigos, sendo que 18 estudos preencheram os crit?rios de inclus?o, compondo a an?lise final. 9 pesquisas avaliaram a confec??o do glide path per se e 11 avaliaram a repercuss?o do glide path no preparo endod?ntico motorizado final. Conclus?o: a revis?o 1 sugeriu que a maioria dos m?todos de mensura??o de curvaturas dos canais radiculares tem potenciais aplica??es cl?nicas, no entanto, h? uma falta de consenso sobre a t?cnica ideal. Al?m do ?ngulo, outros fatores, como raio e posi??o da curvatura, precisam ser mensurados e devem ser levados em considera??o ao se avaliar a curvatura do canal radicular tanto em tratamentos cl?nicos como em ambientes de pesquisa. J? a revis?o 2 revelou que a confec??o motorizada, quando comparada com a confec??o manual, do glide path apresenta resultados similares ou melhores de transporte apical e manuten??o da centraliza??o do canal radicular. Observou-se, tamb?m, que a confec??o do glide path, previamente ao preparo endod?ntico, est? associada com resultados similares ou com a redu??o do transporte apical e a manuten??o da centraliza??o do preparo. Tamb?m foi observado que ocorrem desvios em todas as situa??es.

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