Orientador: Itamar Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-12T18:16:51Z (GMT). No. of bitstreams: 1 Almeida_FabianoCosta_M.pdf: 5847726 bytes, checksum: 145c2a03eac9f5421c57057a5a6f9cb6 (MD5) Previous issue date: 2008 / Resumo: Os instrumentos endodônticos rotatórios de Ni-Ti (limas rotatórias) são utilizados para o preparo dos condutos radiculares e apresentam características de memória de forma, alta flexibilidade e geometria variável. Apesar dessas características, quando solicitados no uso clínico endodôntico, algumas vezes, apresentam fratura no interior dos condutos radiculares tendo como conseqüência uma diminuição no período de utilização, alto custo e a presença de iatrogenias. Este trabalho tem por objetivo realizar uma análise de falha de dois tipos de instrumentos endodônticos rotatórios de Ni-Ti, ProTaper® e ProFile® do mesmo fabricante (Dentsply-Tulsa Dental-Suíça), com geometrias diferentes, utilizando algumas limas com falha em serviço, e ensaios de fadiga de limas sem uso, por flexão rotativa, visando a obtenção de referenciais de micromecanismos de fratura. Foram realizadas análises químicas, por Espectrometria de Fluorescência de raios X e por Difração de raios X, metalográfica, por microscopia óptica, e fratográfica, por microscopia eletrônica de varredura, e ensaios de microdureza e de fadiga, por flexão rotativa, nos dois tipos de limas. Os resultados mostraram que as composições químicas dos dois tipos de limas são iguais, contendo, em peso, 58% de níquel e 42% de titânio, sendo possível identificar, por metalografia, duas fases, Ti2Ni (fase secundária) e TiNi (matriz). Os níveis médios de microdureza encontrados foram de 344HV1, para a lima ProTaper, e de 330HV1, para a lima ProFile. A fratografia possibilitou a identificação de duas regiões na superfície de fratura das limas, com fratura em serviço e submetidas aos ensaios de flexão rotativa, uma correspondente à zona de fadiga, e outra, a zona de fratura final, com avéolos ou "dimples". Foi possível concluir que a falha das limas analisadas foi por fadiga. / Abstract: Rotary endodontic instruments of Ni-Ti (rotary files) are used in order to prepare endodontic dental conducts and show memory shape, high flexibility, and different designs. Although these characteristics, when used in endodontics clinic, sometimes occur fracture inside the conduct of the tooth and, as a result of that, low life, high cost, and iatrogen. The propose of this study is to realize a failure analysis of two different endodontic files, ProTaper® and ProFile®, of Ni-Ti, from the same maker and different shapes, by using some files with failure in service, and fatigue test in files, without use, in rotating bend, to obtain references in terms of micromechanisms of fracture. Were realized chemical analysis, by spectrometry of X-Ray fluorescence and X-Ray diffration, metallograthy, by optical microscopy, and fratographic, by scanning electron microscopy, and microhardness and fatigue tests, in the two types of files, ProTaper and ProFile. The results show the chemical composition of the two files are the same, with 58% of nickel and 42% of titanium, in weight, and was possible to identify, by metallography, two phases, Ti2Ni (secondary phase) and TiNi (matrix). The median levels of microhardness were 344HV1, for the ProTaper® file, and 330HV1, for the ProFile® file. It was possible to identify, by scanning electron microscopy, two different regions on the fracture surface of the files, for fracture from service and from the fatigue tests, one correspondent to the fatigue zone, and another, the final fracture, show dimples. It was possible to conclude that the failure of the analyzed files was by fatigue. / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

El objetivo de este estudio fue comparar la capacidad de remoción de material de relleno entre sistemas de limas reciprocantes y rotatorios. Este fue un estudio in vitro, experimental, prospectivo. Para esta investigación se utilizaron 30 piezas dentarias, premolares inferiores, y se dividieron en 2 grupos de 15 cada uno respectivamente. El primer grupo fue tratado con la lima Easy ProDesign Logic RT y el segundo grupo con la lima R 50 del sistema Reciproc. Como resultado se obtuvo que al comparar la remoción del material de relleno entre los sistemas de limas reciprocantes y rotatorios hay un *P 0.197 indicando que no existe diferencia significativa entre ambos sistemas. Se llegó a la conclusión que los sistemas de limas rotatorias y reciprocantes no mostraron diferencias significativas a la remoción de material de relleno. los sistemas de limas rotatorias y reciprocantes no mostraron diferencias significativas a la remoción de material de relleno al ser comparadas en los tercios cervical, medio y apical. Las limas Easy ProDesign Logic RT lograron la remoción parcial del material en más de dos minutos.Y las lima R 50 del sistema Reciproc lograron la remoción parcial del material al 1-2 minutos en un 60%; mientras que, el 40% en 2 minutos a más. / The objective of this study was to compare the filler removal capacity between reciprocating and rotary file systems. This was a prospective, experimental, in vitro study. For this research, 30 teeth, lower premolars, were used and divided into 2 groups of 15 each respectively. The first group was treated with the Easy ProDesign Logic RT file and the second group with the R 50 file of the Reciproc system. As a result, it was obtained that when comparing the removal of the filling material between the reciprocating and rotary file systems there is a *P 0.197 indicating that there is no significant difference between both systems. It was concluded that the rotary and reciprocating file systems did not show significant differences in the removal of filling material. The rotary and reciprocating file systems did not show significant differences in the removal of filling material when compared in the cervical, middle and apical thirds. The Easy ProDesign Logic RT files achieved partial material removal in more than two minutes. And the R 50 files of the Reciproc system achieved partial material removal in 1-2 minutes by 60%; while, 40% in 2 minutes or more.

De nombreuses avancées ont été réalisées en termes de géométries instrumentales, mouvements de travail et procédés de fabrication des limes endodontiques. Cependant, peu de recherches se sont tournées vers l’utilisation d’alliages à mémoire de forme (AMF) autres que le Nickel-Titane (NiTi). Ce travail se propose de développer un instrument endodontique constitué d’un nouvel AMF aux propriétés mécaniques et antimicrobiennes très prometteuses : le CuAlBe monocristallin. Après une première analyse par éléments finis des paramètres géométriques adéquats pour une lime endodontique en AMF monocristallin à base de CuAlBe, plusieurs prototypes ont été fabriqués puis testés en rotation continue selon un protocole de pénétration / retrait (P/R) dans des canaux artificiels. Des limes endodontiques en NiTi, déjà commercialisées, ont été également testées avec le même protocole. L’objectif de ces recherches était de montrer que les instruments endodontiques en CuAlBe monocristallin présentaient des performances mécaniques équivalentes à ceux en NiTi, en plus de leurs propriétés antimicrobiennes / Many advances have been made in terms of instrumental geometry, working motion and manufacturing processes of endodontic files. However, since the discovery of Nickel-Titanium (NiTi) shape memory alloys (SMA), few research has been carried out on new SMAs. In this context, this work aims to develop an endodontic instrument machined from a new SMA with very promising mechanical and antimicrobial properties: the single crystal CuAlBe. Following a finite element analysis in order to determine adequate geometric parameters for a single crystal CuAlBe SMA endodontic instrument, prototypes were machined and tested following a continuous rotation penetration / removal (P/R) protocol in artificial canals. Endodontic files made of NiTi SMA, already commercialized, were also tested with the same protocol. The aim of this researches is to show that CuAlBe endodontic instruments could lead equivalent mechanical performances to NiTi instruments in addition of their antimicrobial properties

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-04-30T18:33:58Z No. of bitstreams: 1 YURI JOHANN VILAR DE BRITO – DISSERTAÇÃO (PPGEM) 2017.pdf: 3327072 bytes, checksum: 64ff7fa9047331a680ddf175d1592b12 (MD5) / Made available in DSpace on 2018-04-30T18:33:58Z (GMT). No. of bitstreams: 1 YURI JOHANN VILAR DE BRITO – DISSERTAÇÃO (PPGEM) 2017.pdf: 3327072 bytes, checksum: 64ff7fa9047331a680ddf175d1592b12 (MD5) Previous issue date: 2017-05-02 / Capes / A terapia endodôntica executada em canais radiculares curvos com limas de aço inoxidável pode provocar inúmeros acidentes iatrogênicos, resultando em problemas como perfurações do canal. Na tentativa de superar as limitações desses instrumentos menos flexíveis foi desenvolvida a utilização da liga com memória de forma (LMF) de NiTi (Níquel-Titânio) para fabricação de instrumentos endodônticos. A utilização desses instrumentos endodônticos de NiTi modificou os métodos de instrumentação do sistema de canais radiculares, tornando-os mais seguros e rápidos. No entanto, ainda existem poucas informações sobre o comportamento termomecânico destes instrumentos mais avançados. Nesse contexto, no presente trabalho foram realizadas as caracterizações térmica e mecânica de três limas endodônticas de LMF NiTi: Protaper Next X2, Reciproc R25 e WaveOne Primmary. Na caracterização térmica foram realizados ensaios de calorimetria diferencial de varredura (DSC) e resistência elétrica em função da temperatura (RET) para a determinação das temperaturas de transformação de fase das limas, enquanto a caracterização mecânica consistiu de ensaios de flexão simples alternada em regime estático e dinâmico (frequência de 5 Hz) a diferentes temperaturas e deflexões máximas, usando um Analisador Dinâmico Mecânico (DMA) e finalizou com uma análise pós fagida com ensaios de calorimetria diferencial de varredura (DSC) e análise das superfícies fraturadas com um Microscópio Eletrônico de Varredura (MEV) Os resultados obtidos com as três limas revelaram que estes instrumentos endodônticos se encontram na fase conhecida como Fase R, os ensaios quase estáticos revelaram uma forte dependência da Força requerida e a Temperatura, os ensaios cíclicos em flexão alternada para impor deflexões na faixa de ±0,5 mm a ±2,0 mm as limas Reciproc R25 mostraram maior tempo de vida cíclica do que as demais, e com o aumento da temperatura de teste de 35 oC para 45 oC, verificou-se que a força para impor as deflexões foram maior e a vida em fadiga das limas reduziu consideravelmente. / Endodontic therapy performed on curved root canals with stainless steel files can cause many iatrogenic accidents, resulting in problems such punctures the canal. In an attempt to overcome the limitations of the less flexible instruments, the alloy with shape memory and NiTi (Nickel-Titanium) for manufacturing endodontic instruments were developed. The use of the NiTi instruments modified methods of instrumentation of the root canal system, making them safer and faster. However, there is still little information on the thermomechanical behavior of more advanced instruments. In this context, the present work is done the thermal and mechanical characterization of three endodontic commercial LMF NiTi files: Protaper Next X2, Reciproc R25 and WaveOne Primmary were performed. For thermal characterization were performed differential scanning calorimetry (DSC) tests and electric resistance as a function of temperature (RET) for determining phase transformation temperatures of files, while the mechanical characterization consisted of static bending tests and dynamic regime (5 Hz frequency) at different temperatures and maximum deflections using a Dynamic Mechanical Analyzer (DMA) and finalizes with post fracture analysis with differential scanning calorimetry (DSC) and fractured surface analysis with an Electron Microscope. The results obtained with the three files showed that endodontic files are in phase known as Phase R, the quasi static tests revealed a strong dependence of the Required Force and the Temperature, the cyclic tests in alternating bending to impose deflections in the Range from ± 0.5 mm to ± 2.0 mm, the Reciproc R25 showed longer cycle life than the others, and with the test temperature rise from 35 °C to 45 °C, it was found that the force to impose the deflections were higher and the fatigue life of the limes reduced considerably.