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Journal articles on the topic "NiTi rotary system"

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AlRahabi, Mothanna K., and Hani M. Ghabbani. "Removal of a separated endodontic instrument by using the modified hollow tube–based extractor system: A case report." SAGE Open Medical Case Reports 8 (January 2020): 2050313X2090782. http://dx.doi.org/10.1177/2050313x20907822.

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The frequency of separation of NiTi rotary instruments has increased with the increasing use of these instruments, and this error may result from inadequate experience of using these instruments. This iatrogenic error can complicate root canal treatment, and special experience is required to manage this problem. This case report describes the management of the separation of an F3 instrument from a ProTaper NiTi rotary system. A 30-year-old man was referred to the College of Dentistry, Taibah University (Saudi Arabia) with an intracanal separated NiTi rotary instrument (F3 of the ProTaper system; Dentsply Maillefer, Ballaigues, Switzerland) in the canal of the maxillary right canine. The separated instrument was removed by using the modified hollow tube–based extractor system. The present case revealed that sometimes a simple method can be an effective alternative of a professional method; using NiTi rotary instruments with strict adherence is important for the prevention of instrument separation.
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Dhingra, Anil, and Surbhi Kakar. "Shaping Potential of Manual NiTi K-File and Rotary ProTaper and Analyzing the Final Outcome of Shaped Canals using CT." Journal of Contemporary Dental Practice 14, no. 3 (2013): 451–55. http://dx.doi.org/10.5005/jp-journals-10024-1343.

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ABSTRACT Aim To assess and compare the shaping potential of manual NiTi K-files and Rotary ProTaper instruments in narrow canals using CT. Objective To assess the shaping potential of manual NiTi K-files and Rotary ProTaper and analyzing the final outcome of shaped canals using CT and determining different variables, like • Working time • Change in volume • Change in cross-sectional area. Materials and methods From a pool of fifty freshly extracted permanent maxillary molars (1st and 2nd), 30 were selected with curvatures (20 to 40°) (Schneider 1971). Tissue fragments and calcified debries were removed from the teeth by scaling. The teeth were then stored in normal saline until used. All the mesiobuccal canals were scanned by CT to obtain preinstrumented images. Teeth were scaled and stored in normal saline. This study was divided in two groups with 15 samples each. Group I (ProTaper Rotary) Canals were instrumented with Protaper Rotary instruments using crown down technique according to manufacturer's instructions. Group II (NiTi K-file) Were instrumented by NiTi K-files using step back technique with a quarter turn/pull motion. Evaluations of working time Comparative evaluations of working time was done for both the experimental groups. CT analysis and measurements The samples were analyzed and evaluated for: • Postinstrumentation change in volume. • Postinstrumentation change in cross-sections area. Result From the observations and statistical analysis carried out in this study, it was found that: There was a statistically significant difference between all the parameters judged for the present study that is: 1. Instrumentation with ProTaper Rotary system took significantly less time than instrumentation with manual NiTi K-file. 2. Change in the canal volume following instrumentation with ProTaper Rotary was significantly greater than that produced by manual NITi K-file. 3. a. Change in cross-section area at 2 and 3 mm from the apex was significantly greater with manual NiTi K-file as compared to ProTaper Rotary. b. Change in cross sections at 4.5, 6 and 7.5 mm from the apex with ProTaper Rotary was significantly greater than that produced by manual NITi K-file. Conclusion This clearly establishes that there is a drastic difference in the shaping ability of manual and Rotary NiTi instruments used with step back and crown down technique respectively with the rotary instrumentation being faster and producing greater changes in the canal anatomy. How to cite this article Kakar S, Dhingra A, Sharma H. Shaping Potential of Manual NiTi K-File and Rotary ProTaper and Analyzing the Final Outcome of Shaped Canals using CT. J Contemp Dent Pract 2013;14(3):451-455.
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Shenoy, Vanitha U., Ritesh B. Pawar, Sumanthini MV, and Saimanaaz AH Shaikh. "Comparison of the Effects of Three Different Nickel–titanium Rotary Instruments on the Fracture Resistance of Obturated Roots: An in vitro Study." Journal of Contemporary Dentistry 7, no. 2 (2017): 86–90. http://dx.doi.org/10.5005/jp-journals-10031-1191.

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ABSTRACT Aim The aim of the article is to compare the effects of three different nickel–titanium (NiTi) rotary instruments on the fracture resistance of obturated roots. Materials and methods A total of 100 permanent mandibular premolars were randomly divided into four groups of 25 teeth each and biomechanical preparation was done: group I: stainless steel K-hand files (HFs), group II: ProTaper NiTi instruments (PT), group III: HyFlex CM NiTi instruments (HCM), and group IV: K3XF NiTi instruments. Following root canal preparation, the canals were obturated using lateral condensation. A light body silicone impression material was used to simulate the periodontal ligament (PDL). Fracture resistance was tested in an Instron testing machine. Statistical analysis Data were analyzed with Kruskal–Wallis test. Results There was no difference in significance (p < 0.05) among the different groups tested with respect to their fracture resistances. Conclusion The present study concluded that rotary instrumentation could result in an increased chance for dentinal defects as compared with hand instrumentation. Greater taper rotary NiTi instruments do not increase the fracture susceptibility of roots, which in turn depends on various factors other than instrumentation alone. Clinical significance Greater taper achieved by rotary NiTi files during canal preparation facilitates efficient irrigation and complete debridement. Root fracture might occur as a result of microcracks or craze lines that propagate with repeated stress application by occlusal forces and also during canal preparation. Based on the results obtained, it can be decided whether the use of the newer rotary NiTi system contributes to endodontic success and long-term survival of endodontically treated teeth. How to cite this article Shaikh SAH, Shenoy VU, Sumanthini MV, Pawar RB. Comparison of the Effects of Three Different Nickel–titanium Rotary Instruments on the Fracture Resistance of Obturated Roots: An in vitro Study. J Contemp Dent 2017;7(2):86-90.
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Pitchiah, Pragadeesh A., and Prathima G. Shivashankarappa. "Rotary Files in Pediatric Dentistry: From Then Till Now." Journal of Scientific Dentistry 10, no. 2 (2020): 55–57. http://dx.doi.org/10.5005/jp-journals-10083-0926.

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ABSTRACT The introduction of adult NiTi rotary file system for children was a revolution in the field of pediatric endodontics. With the use of these files, cost-effective, consistent obturations were made possible in shorter instrumentation time. The various restraints of adult rotary files such as file length and taper created the need for newer rotary file system. These voids were fulfilled with the advent of exclusive pediatric rotary file—Kedo-S file system. In this article, we have discussed how the innovative pediatric rotary files have made its mark overpowering the limitations of the existing adult rotary file system in children. How to cite this article: Pitchiah PA, Shivashankarappa PG. Rotary Files in Pediatric Dentistry: From Then Till Now. J Sci Dent 2020;10(2):55–57.
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Zarei, Mina, Maryam Javidi, Mahdi Erfanian, Mahdi Lomee, and Farzaneh Afkhami. "Comparison of Air-driven vs Electric Torque Control Motors on Canal Centering Ability by ProTaper NiTi Rotary Instruments." Journal of Contemporary Dental Practice 14, no. 1 (2013): 71–75. http://dx.doi.org/10.5005/jp-journals-10024-1273.

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ABSTRACT Aim Cleaning and shaping is one of the most important phases in root canal therapy. Various rotary NiTi systems minimize accidents and facilitate the shaping process. Todays NiTi files are used with air-driven and electric handpieces. This study compared the canal centering after instrumentation using the ProTaper system using Endo IT, electric torque-control motor, and NSK air-driven handpiece. Materials and methods This ex vivo randomized controlled trial study involved 26 mesial mandibular root canals with 10 to 35° curvature. The roots were randomly divided into 2 groups of 13 canals each. The roots were mounted in an endodontic cube with acrylic resin, sectioned horizontally at 2, 6 and 10 mm from the apex and then reassembled. The canals were instrumented according to the manufacturer's instructions using ProTaper rotary files and electric torque-control motors (group 1) or air-driven handpieces (group 2). Photographs of the cross-sections included shots before and after instrumentation, and image analysis was performed using Photoshop software. The centering ability and canal transportation was also evaluated. Repeated measurement and independent t-test provided statistical analysis of canal transportation. Results The comparison of the rate of transportation toward internal or external walls between the two groups was not statistically significant (p = 0.62). Comparison of the rate of transportation of sections within one group was not significant (p = 0.28). Conclusion Use of rotary NiTi file with either electric torquecontrol motor or air-driven handpiece had no effect on canal centering. Clinical significance NiTi rotary instruments can be used with air-driven motors without any considerable changes in root canal anatomy, however it needs the clinician to be expert. How to cite this article Zarei M, Javidi M, Erfanian M, Lomee M, Afkhami F. Comparison of Air-driven vs Electric Torque Control Motors on Canal Centering Ability by ProTaper NiTi Rotary Instruments. J Contemp Dent Pract 2013;14(1):71-75.
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Kuga, Milton Carlos, Mário Tanomaru-Filho, Gisele Faria, Marcus Vinicius Reis Só, Tiago Galletti, and José Roberto Sampaio Bavello. "Calcium hydroxide intracanal dressing removal with different rotary instruments and irrigating solutions: a scanning electron microscopy study." Brazilian Dental Journal 21, no. 4 (2010): 310–14. http://dx.doi.org/10.1590/s0103-64402010000400004.

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This study evaluated the efficacy of 2 types of rotary instruments employed in association with sodium hypochlorite (NaOCl) or EDTA in removing calcium hydroxide (CH) residues from root canals dentin walls. Forty-two mandibular human incisors were instrumented with the ProTaper System up to F2 instrument, irrigated with 2.5% NaOCl followed by 17% EDTA and filled with a CH intracanal dressing. After 7 days, the CH dressing was removed using 4 techniques: NiTi rotary instrument size 25, 0.06 taper (K3 Endo) and irrigation with 17% EDTA (Group 1), NiTi rotary F1 instrument (ProTaper) and irrigation with 17% EDTA (Group 2), NiTi rotary instrument size 25, 0.06 taper and irrigation with 2.5% NaOCl (Group 3) and NiTi rotary F1 instrument and irrigation with 2.5% NaOCl (Group 4). Two roots without intracanal dressing were used as negative controls. Teeth were evaluated by scanning electron microscopy, in the cervical and apical canal thirds. None of the techniques removed the CH dressing completely. In the apical and cervical thirds, F1 instrument was better than instrument size 25, 0.06 taper in removing CH residues (p<0.05), regardless of the final irrigating solution. No difference was found between the irrigating solutions in the groups of F1 instrument and of instrument size 25, 0.06 taper (p>0.05). The negative controls had no CH residues on the dentin walls. In conclusion, the ProTaper F1 instrument was better than K3 Endo instrument size 25, 0.06 taper in the removal of CH intracanal medication, regardless of irrigating solution used.
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Zahid, N., S. A. Khan, A. Saqib, and A. Tariq. "Comparison of rotary NiTi reciprocating file systems using Cone Beam CT in root canal transportation." Pakistan Journal of Medical and Health Sciences 15, no. 6 (2021): 1206–9. http://dx.doi.org/10.53350/pjmhs211561206.

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Aim: T assess the root canal transportation caused by these rotary NiTi reciprocating file systems using 3D cone beam computed tomography Method: This experimental study was conducted on 60 samples of rotary NiTi reciprocating file systems using CBCT. The extent of canal transportation and the centering ratio was analyzed using independent sample t test. The significance level was set at 95%. Results: Mean apical canal transportation was lower in wave one Gold groups as compare to Reciproc (0.8724±0.04SD vs 0.9463±0.02SD, p=0.000). Mean apical canal transportation at 5 mm was lower in wave one gold group as compare to reciproc blue group (0.5610±0.02SD vs 0.7253±0.06SD, p=0.000). Mean apical canal transportation at 8mm was lower in wave one group as compare to reciproc blue (0.358±0.03SD vs 0.5766±0.10SD, p=0.000). Conclusion: Wave one Gold had high centering ability and lower canal transportation as compare to Reciproc Blue single file system. CBCT is an efficient method of understanding Canal transportation Keywords: CBCT, NiTi wire, Root canal transportation, Reciproc blue
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Fatima, Alvi, Hares Shabir, Arushi Goyal, Akshun S Gupta, Faiz Khan, and Akanksha Sood. "A literature review of single file NiTi rotary system in endodontics." IP Indian Journal of Conservative and Endodontics 6, no. 2 (2021): 85–87. http://dx.doi.org/10.18231/j.ijce.2021.019.

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The most important step in the success of the root canal treatment is the proper cleaning and shaping of the canal system. Cleaning and shaping means the removal of the entire pulpal tissue from the canal, so that there will be no residue left of any vital structure, that may cause any painful or infectious condition for the future. Some times there occurs difficulty in cleaning as well as shaping of the root canal in the posterior tooth or teeth, where the anatomy of the root is some what curved, and there occur difficulty in removing the vital tissue along with difficulty in achieving the accurate working length of the tooth. In this type of situation use of nickel titanium single file system is quite beneficial.
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Diana, Sherli, and Pribadi Santosa. "Perawatan Satu Kunjungan pada Premolar Pertama Atas Menggunakan Protaper Rotary dan Restorasi Resin Komposit." Majalah Kedokteran Gigi Indonesia 20, no. 1 (2013): 85. http://dx.doi.org/10.22146/majkedgiind.8385.

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Preparasi kemomekanik pada saluran akar meliputi instrumentasi mekanis dan irigasi antibakteri yang secara prinsip dapat langsung mengeliminasi mikroorganisme pada sistem saluran akar. sejak diperkenalkan pada tahun 1988, instrumen rotary nikel-titanium (niti) telah digunakan secara umum dalam perawatan endodontik karena kemampuannya membentuk saluran akar dengan prosedur komplikasi yang minimal. Tujuan dari laporan kasus ini adalah untuk memaparkan perawatan saluran akar satu kunjungan menggunakan protaper rotary dan restorasi resin komposit gigi premolar. Penderita pria 21 tahun datang ke RSGM Prof. Soedomo UGM Yogyakarta mengeluhkan gigi belakang atas kiri yang berlubang tapi tidak sakit dan pasien ingin dirawat.Gigi Premolar satu atas kiri terdapat kavitas disto oklusal dengan pulpa terbuka. Pemeriksan objektif pada gigi 24 sondasi, perkusi, palpasi, dan tes termal menunjukkan hasil negatif.Pemeriksaan radiografis tidak terdapat lesi, lamina dura tidak terputus dan saluran akar jelas dan lurus. Pada kasus ini dilakukan perawatan saluran akar dengan menggunakan ProTaper rotary ( X-Smart, Dentsply). Pasca perawatan saluran akar, gigi premolar satu atas kiri dilakukan tumpatan resin komposit kelas II.Hasil evaluasi klinik saat kontrol tidak ada keluhan rasa sakit, pemeriksaan objektif juga tidak ada rasa sakit, warna gigi serasi dengan warna gigi tetangga.prognosis pada kasus ini baik dan tidak ada keluhan. Kesimpulan paska perawatan saluran akar satu kunjungan dengan instrumenrotary, tidak terdapat keluhan.Penggunaan Instrumen rotary Nikel-Titanium (NiTi) sangat flexible dengan prosedur komplikasi yang minimal, dan hemat waktu.One Visit Treatment of Upper Premolar Tooth Using Rotary Protaper and Composite Resin Restoration. Chemomechanical preparation for root canal including mechanic instrumentation and anti-bacterial irrigation principally could eliminate microorganisms in root canal system. Many instruments and techniques have been described and developed for initial root canal treatment. Since first established in 1988, nikel-titanium (NiTi) rotary instrument has been used for endodontic treatment because of its capability in forming the root canal with minimal complication procedure. Clinically, safe use of NiTi instrument and understanding of the alloy basic metallurgy including fracture mechanism and its correlation with root canal anatomy in order to set the safe use of NiTi instrument are required. This research will explain about biological principal of root canal preparation with correct technique and instrumentation system using NiTi. A 21 year-old patient in RSGM Prof. Soedomo UGM Yogyakarta complained about his left side upper jaw, posterior teeth with cavity, painless and the patient wanted to treat the teeth. The left maxilla first premolar teeth has a distooclussal cavity, open pulp. Based on the radiograph test, there found no lession, lamina dura was fine, and root canal was clear and straight. In this case, the patient was treated with crown down rotary X-Smart (Dentsply) technique for root canal treatment. After the root canal treatment had been conducted, the teeth were restorated with class II composite resin. After the treatment, it is found that there is no pain in the teeth, the colour of teeth match with others, and the prognosis for this case is good.
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Torres, Carlos Rocha Gomes, Eduardo Galera da Silva, Ana Paula Martins Gomes, et al. "Cone-beam Computed Tomographic Analysis: Comparison of the Efficacy of Two Rotary Retreatment Systems for Removal of Filling Material from Primary Teeth Obturated with Contemporary Endodontic Sealers." World Journal of Dentistry 6, no. 3 (2015): 129–37. http://dx.doi.org/10.5005/jp-journals-10015-1328.

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ABSTRACT Introduction This study has used cone-beam computed tomography (CBCT) to evaluate the efficacy of two different nickel titanium (NiTi) rotary retreatment systems for removal of filling material from teeth obturated with contemporary endodontic sealers. The operative time required for removal of root filling materials was also evaluated. Methods Sixty root canals were randomly divided into three groups according to the sealer used for obturation: AH Plus Jet, mineral trioxide aggregate (MTA) Fillapex, and RoekoSeal Automix (RSA) (all, n = 20). After obturation, each group was subdivided into two subgroups according to the NiTi retreatment rotary system: Mtwo retreatment (Mtwo-R) file subgroup and ProTaper-UR subgroup—both instrumented with Mtwo-R files. Teeth were scanned with a microcomputed tomography before and after obturation. Results Residual filling material was observed in 100% of the specimens after retreatment. No difference was found between Mtwo-R and ProTaper-UR systems (p > 0.05). The RSA was more effectively removed from dentin walls than AH Plus Jet (p < 0.05), with no difference to MTA Fillapex (p > 0.05). Thus, teeth obturated with RSA required less operative time to be retreated (both, p<0.05). Conclusion ProTaper-UR and Mtwo-R systems were effective in removing the filling materials after instrumentation, but they could not eliminate them completely. Moreover, teeth obturated with silicone-based sealer RSA showed less residual filling material in dentin walls compared to the epoxy resin-based sealer (AH Plus Jet), which exhibited no difference compared to the salicylate resin-based sealer (MTA Fillapex). Teeth obturated with silicon-based sealer also required less operative time to be retreated despite the NiTi rotary retreatment system tested. How to cite this article Moreira CS, Martinho FC, Coelho MPB, Júnior LRMC, da Silva EG, Torres CRG, Gomes APM. Cone-beam Computed Tomographic Analysis: Comparison of the Efficacy of Two Rotary Retreatment Systems for Removal of Filling Material from Primary Teeth Obturated with Contemporary Endodontic Sealers. World J Dent 2015;6(3):129-137.
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Dissertations / Theses on the topic "NiTi rotary system"

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Consolmagno, Elaine Cristina. "Avaliação por meio da microscopia eletrônica de varredura da limpeza e deformação de instrumentos rotários após a instrumentação de canais radiculares." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/25/25138/tde-21032012-152257/.

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O presente estudo teve como objetivo avaliar, por meio da microscopia eletrônica de varredura (M.E.V.), a remoção de detritos e deformação superficial sofrida pelos sistemas endodônticos rotatórios de NiTi BioRace (BR); Protaper (PT) e Twisted File (TF) após cada uso, totalizando cinco usos, simulando as condições clínicas. Um total de 75 molares superiores humanos extraídos cuja raiz disto-vestibular apresentava curvatura de 0 a 5° e mésio-vestibular entre 20 e 30° de acordo com o método de Weine, foram selecionados e divididos em três grupos com 25 espécimes. Para o grupo I: realizou-se instrumentação com o sistema BR; para o grupo II com o sistema PT e para o grupo III, com o TF. Foram utilizadas cinco caixas de cada sistema rotatório para instrumentar os canais mesio e distovestibulares. Inicialmente os instrumentos foram fotografados em M.E.V. com aumento de 35 vezes, utilizados uma vez e em seguida passaram por um protocolo de limpeza baseado no proposto por Parashos, Linsuwanont e Messer (2004) previamente a esterilização e, em seguida eram analisados em M.E.V., antes do uso seguinte. Esses procedimentos foram realizados até o último uso. Os dados de limpeza foram submetidos ao teste estatístico de Kruskal Wallis para comparação global e ao teste de Dunn para comparação individual dos grupos, enquanto para análise da deformação foram submetidos ao teste estatístico do Qui-quadrado para comparação global e ao teste exato de Fisher para as comparações individuais, todos com significância de 5%. Os resultados apontaram diferenças estatisticamente significantes quanto à limpeza para o sistema BR com maior quantidade de detritos remanescentes do processo de fabricação em relação ao PT e TF; após os 5 usos, os sistemas BR e PT apresentavam-se mais limpos em relação ao início do experimento, enquanto o TF permaneceu com quantidade semelhante de detritos superficiais. Ocorreu deformação em 40% do sistema BR, sendo 5% fratura e, 100% do TF, sendo 40% fratura. O sistema PT não sofreu danos consideráveis de acordo com os critérios avaliados. Por meio dos resultados obtidos neste estudo, concluiu-se que o protocolo de limpeza utilizado não proporcionou superfícies completamente limpas tanto no decorrer quanto ao final do experimento e quanto a deformação superficial, o sistema TF apresentou o pior resultado, seguido do BR, enquanto o PT que não apresentou qualquer deformação quanto aos critérios avaliados.<br>The aim of this study was to evaluate by scanning electron microscopy (SEM) the debris removal and deformation surface by rotary NiTi endodontic systems BioRace (BR), Protaper (PT) and Twisted File (TF) before each use, total five uses, simulating clinical conditions. A total of 75 extracted human molars whose disto-vestibular roots had curvature between 0 and 5 degrees and mesio-vestibular roots had curvature between 20 and 30 degrees according to the Weine method were selected and divided into three groups of 25 specimens. In the Group I: was used the BR system, group II was used the PT system and group III was used the TF system to shaping the mesio and distovestibular molars canals. Were used a total of five boxes to each rotary system. Initially, the instruments were examined by SEM at a magnification of 35x, then used into root canals and submitted through the cleaning protocol based on proposed by Parashos, Linsuwanont and Messer (2004) prior to sterilization for further examination by SEM, before the next use. These procedures were carried out until the last use. The cleaning data were analysed using statistical Kruskal Wallis test for global comparison and the Dunn test for individual groups comparison. The deformation data were analysed using Chi-square test for overall comparison and Fisher exact test for individual comparisons, both with 5% significance. The results showed the following statistically significant differences regarding cleaning to BR system with highest amount of debris remaining from the manufacturing process in relation to the PT and TF; after the five uses, the BR and PT systems were cleaner in relation to the initial experiment, but the TF system had the same debris amount. The deformation occurred in 40% of the BR system, with 5% fractured and 100% of the TF, with 40% fractured. The PT system has not suffered considerable damage in accordance with the criteria evaluated. The results of this study showed that the protocol did not provide cleaning surfaces completely free of debris, especially in the TF system, while for the BR and PT, resulting in cleaner surfaces at the end of the experiment compared with the dirt initial (immediately removed from their packaging). The surface deformation of TF system presented the worst results, followed by the BR and PT did not show any deformation on the criteria evaluated.
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Ankrum, Matthew Todd. "K3 Endo, Pro Taper, and Pro File Systems: Breakage and Distortion in Severely Curved Roots of Molars." VCU Scholars Compass, 2003. http://scholarscompass.vcu.edu/etd/842.

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K3 ENDO, PRO TAPER, AND PRO FILE SYSTEMS: BREAKAGE AND DISTORTION IN SEVERELY CURVED ROOTS OF MOLARS.By Matthew T. Ankrum, D.D.S.A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University.Virginia Commonwealth University, 2003Major Director: Gary R. Hartwell, D.D.S., M.S.Chairman and Professor, Department of EndodonticsIt was the aim of this study to investigate the incidence of file breakage and distortion when the Pro Taper, K3 Endo and ProFile systems were used to instrument canals in the severely curved roots of extracted molars.Forty-five roots of extracted mandibular and maxillary molars with curvatures between 40 and 75 degrees were chosen for use in this study. The roots in Group One were instrumented with the Pro File (PF) system and served as the control group. Roots in Group Two were instrumented with the Pro Taper (PT) system and those in Group Three were instrumented with the K3 Endo (K3) system. The three systems were used according to the manufacturers' instructions.The proportion of files distorted was 15.3% for the PF group, 2.4% for the PT group, and 8.3% for the K3 group. There was a statistically significant difference between the PF and PT groups (p = .0079). The percentage of broken files was 1.7% for the PF group, 6.0% for the PT group and 2.1% for the K3 group. No statistically significant differences were found between these three groups (p = .4243). The results of this study showed that these three rotary tapered systems were not significantly different with regard to breakage. There were significantly more distorted files in the PF group when compared to the PT group, with regard to distortion there was no significant difference between the PT and K3 and the PF and K3 groups.
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Conference papers on the topic "NiTi rotary system"

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Gurley, Austin, Kyle Kubik, Tyler Ross Lambert, David Beale, and Royall Broughton. "Bowden Tube NiTi Actuators With Linear Parameter Varying Model and Sliding Mode Control." In ASME 2017 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/smasis2017-3989.

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One of the primary difficulties to implementing NiTi shape memory alloys as robotic actuators is reliably amplifying their low linear strain to large effective displacements. Bowden tubes, called “push-pull cables” in other industries, allow a long length of Shape Memory Alloy (SMA) wire to fit in a small space; this provides a method for increasing effective SMA actuator strain without compromising space or complexity of the entire mechanism. The mechanical advantage of the Bowden tube provides faster actuation speeds, but comes at a cost of increased thermal capacitance resulting in higher power consumption. A feedback control system has been formed comprising the Bowden tube actuator, a rotary platform, and a microcontroller. The controller heats the SMA by passing current through the SMA wire using pulse-width-modulation. After describing the creation of the electro-mechanical system, its capabilities and limitations are discussed. Linear Parameter Varying (LPV) models of SMA are used to determine the range of characteristics the inherently nonlinear SMA system will exhibit. A sliding mode controller is designed based on these characteristics, and implemented in the prototype. Sliding-mode control is shown to be a powerful tool for SMA control even when system parameters are uncertain.
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Welsch, Felix, Susanne-Marie Kirsch, Nicolas Michaelis, et al. "Elastocaloric Cooling: System Design, Simulation, and Realization." In ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/smasis2018-7982.

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Elastocaloric cooling is a novel environment-friendly alternative to vapor compression-based cooling systems. This solid-state cooling technology uses NiTi shape memory alloys (SMAs) as cooling medium. SMAs are well known for lightweight actuator systems and biomedical applications, but in addition, these alloys exhibit excellent cooling properties. Due to the high latent heats activated by mechanical loading/unloading, large temperature changes can be generated in the material. Accompanied by a small required work input, this also leads to a high coefficient of performance superior to vapor compression-based systems. In order to access the potential of these alloys, the development of suitable thermodynamic cooling cycles and an efficient system design are required. This paper presents a model-based design process of an elastocaloric air-cooling device. The device is divided into two parts, a mechanical system for continuously loading and unloading of multiple SMA wire bundles by a rotary motor and a heat transfer system. The heat transfer system enables an efficient heat exchange between the heat source and the SMA wires as well as between the SMA wires and the environment. The device operates without any additional heat transfer medium and cools the heat source directly, which is an advantage in comparison to conventional cooling systems. The design of this complex device in an efficient manner requires a model approach, capable of predicting the system parameters cooling power, mechanical work and coefficient of performance under various operating conditions. The developed model consists of a computationally efficient, thermo-mechanically coupled and energy based SMA model, a model of the system kinematics and a heat transfer model. With this approach, the complete cooling system can be simulated, and the required number of SMA wires as well as the mechanical power can be predicted in order to meet the system requirements. Based on the simulation results a first prototype of the elastocaloric cooling system is realized.
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James, Erik, Jamil Grant, Michael Alberter, Nastassja Dasque, Cynthia Price, and William J. Craft. "Nickel-Titanium Shape Memory Alloy Motors and Electromechanical Devices." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-15119.

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Abstract:
Shape memory alloys (SMA) have been an extensively used material for actuators in micro-electromechanical systems (MEMS) because actuation force and displacement are greatest in SMA amongst many actuator materials [1]. Of the alloys currently available for SMA actuators, the most popular system is Nitinol (or NiTi) due to its good oxidation resistance, reversible martensitic transformation, broad range of transformation temperatures (from -100 - 100 °C), and specific power density [2]. Current commercially available SMA wire has easily achieved no-load strain of 5% with medium gage SMA wires demonstrating an axial force capacity of 2 Newtons or more. While the potential use of SMA materials in a thermal-electric motor has been documented beginning in the 1980's, there are a number of new allows and fatigue-resistant materials that may lead to more general designs with a wide range of motions and applications. Shape memory alloys are a special type of material that exhibit two unique properties, pseudo-elasticity and shape memory effect (SME). SMA undergoes SME because of martensitic or diffusionless transformation where each atom has a slight displacement, creating observable changes throughout the structure as the allow changes states. This alloy has the ability, once heated, to return to its parent austenite phase where it exists at higher symmetry. Upon cooling, the material returns to one of many lower symmetry martensitic phases. This thermal cycle is shown in Figure 1. [3,4]. It is even possible for many variants of martensite to be present in the same material. Pseudo-elasticity is a rubber-like flexibility that allows the SMA to be contorted for a variety of purposes. Once contorted, the application of heat will cause the alloy to undergo martensitic transformation. Upon completion of the cycle, the alloy will have returned to its original shape. The development of SMA-based electromechanical devices delivers traditional mechanical motion with non-traditional methods. Rather than electromagnetic components rotating about a central axis to produce power, the rotary SMA motor utilizes contracting elements, and mush as spark ignition rotary engine, it can be designed to produce angular motion. Motion is accomplished with sequenced electrical signals sent across each element mounted between an eccentric crank. Rotary motion is produced during the power portion of the cycle for specific SMA elements under the application of an electrical signal. Based on this concept, our team developed a demonstration model with four active elements. We have demonstrated rotary motion of the device for an extended period of time, and we believe that macro-scale models can reduce the concept substantially and perhaps to the MEMS level.
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