In Vitro Comparative Study Of The Influence Of Instrument Taper On The Fracture Resistance Of Endodontically Treated Teeth

Context: Preparation of the root canal system is recognized as being one of the most important stages in root canal treatment which removes organic debris and microorganisms from the root canal system by means of chemico- mechanical preparation and irrigation of the canals. The use of nickel-titanium instruments has drastically reduced the time and the difficulties that were encountered with traditional hand instruments made up of stainless steel. Utilizing properties of super-elasticity, shape memory and different tapers of these instruments reduces not only the possibility of canal transportation but also affects both the geometry and volume of root canals. This subjects the root dentin to stress and consequently dentinal defects which increases the risk of root fracture during or after root canal treatment. Clinicians now have the opportunity to choose from differently tapered instruments having unique characteristics in their geometry and metallurgy. These are progressively tapered instruments, fixed tapered instruments, and variable tapered instruments, which come with the benefit of conforming to the root canal anatomy as well as removing dentin as little as possible while cleaning and shaping. The aim of this study was to examine the influence of instrument taperAim: on the fracture resistance of endodontically treated roots under in vitro experimental conditions.Conclusion: Under the limitations of this study in in-vitro conditions there were no significant differences between the fracture loads between the different file systems used, however samples prepared with Hyflex EDM recorded the highest fracture resistance, followed by ProTaper NEXT, ProTaper Gold and NeoEndo Flex respectively.

Evaluation of Root Canal Cleaning Efficacy of Selfadjusting Files, Protaper Rotary, and Manual K?Files in Primary Teeth ? An In vitro Comparative Study

Background: The success of pulpectomy depends on complete eradication of microbial load by cleaning and shaping the primary root canals that is difficult to achieve because of anatomical intricacy of primary pulp dentin complex. Numerous instruments were tried, however, they proved to be inadequate. Selfadjusting file (SAF) is a newer file system that facilitates less dentin removal with maximal cleansing of root canals. Aim: To evaluate and compare the in vitro root canal cleaning efficacy with SAF, Protaper Universal, and Hand K?files in primary teeth. Materials and Methods: Sixty extracted primary anterior teeth were randomly divided into three groups by lottery method. Access cavity was prepared, the canals were enlarged up to 20 K file, and an Indian ink was injected into each canal. Then the Group I (n = 20) was treated with SAF, Group II (n = 20) with Rotary Protaper Universal and Group III (n = 20) with Hand K?files and the root canal cleaning efficacy was evaluated based on the amount of Indian ink remaining in the canal walls under stereomicroscopy. Data were analyzed using Kruskal–Wallis one way ANOVA test and post hoc Tuckey test for intragroup and intergroup comparison, respectively. Results: A statistically highly significant difference was observed with SAF (mean = 1.5), Protaper (mean = 2.5), and Hand K?files (mean = 2.9). However, there was no significant difference in root canal cleaning efficacy with Protaper Universal and Hand K?files. Conclusion: The SAFs had shown superior cleaning efficacy compared with rotary Protaper Universal and manual K files.

Evaluation of the rotary kinematics between actual and set speeds of X-Smart Plus, VDW.Silver and iRoot motors

Abstract The present study evaluated the actual rotational speed of three different endodontic motors compared to the values provided by the manufacturers. A total of three endodontic motors (X-Smart Plus, VDW.Silver, and iRoot) were tested at 400 rpm and 800 rpm and 2 N/cm2 torque. The kinematics of the devices was recorded by using a custom angle-measuring disc with a 50-mm diameter attached to the handpiece provided by the manufacturer, whereas their movement was captured by a high-speed camera at 2,400 frames per second, 800 x 800 pixel-resolution and distance of 0.3 m from the target object. Statistical analysis was performed at a significance level of 5%. At 400 rpm, the iRoot motor had a value of 17.94 rpm above that indicated by the manufacturer, which was significantly different from those of X-Smart Plus (5.20 rpm below that indicated by the manufacturer) and VDW.Silver (0.62 rpm above that indicated by the manufacturer) motors (P < 0.05). At 800 rpm, the iRoot motor had a value of 51.34 rpm below that indicated by the manufacturer, whereas the X-Smart Plus motor had a value of 13.00 rpm below that indicated by the manufacturer (P > 0.05). The VDW.Silver motor statistically differed from the iRoot and X-Smart Plus ones, showing a value of 1.68 rpm above that indicated by the manufacturer. In conclusion, the X-Smart Plus, VDW.Silver, and iRoot motors showed lower variations in the rotational speed values compared to those reported by their manufacturers. The endodontic motors presented different behaviors between them, with the VDW.Silver motor presents the most accurate values and the iRoot presents the most divergent values.

Resumo O presente estudo avaliou a real velocidade rotacional de três diferentes motores endodônticos comparados aos valores fornecidos pelos fabricantes. Um total de três motores endodônticos (X-Smart Plus, VDW.Silver e iRoot) foram testados a 400 rpm e 800 rpm e torque de 2 N/cm2. A cinemática dos dispositivos foi verificada utilizando-se um disco customizado de 50 mm de diâmetro acoplado ao contra ângulo fornecido pelo fabricante e o movimento foi capturado através de uma câmera ajustada em 2400 quadros por segundo com resolução de 800 x 800 pixels distante 0,3 m do objeto alvo. A análise estatística foi realizada com nível de significância de 5%. A 400 rpm, o motor iRoot apresentou 17,94 rpm acima do indicado pelo fabricante, sendo o valor significativamente diferente do X-Smart Plus (5,20 rpm abaixo do indicado pelo fabricante) e VDW.Silver (0.62 rpm acima do indicado pelo fabricante) (P > 0,05). A 800 rpm, iRoot apresentou 51.34 rpm abaixo do indicado pelo fabricante e X-Smart Plus 13,00 rpm abaixo do indicado pelo fabricante (P > 0,05). VDW.Silver foi estatisticamente diferente de iRoot e X-Smart Plus, apresentando 1,68 rpm acima do indicado pelo fabricante. Concluiu-se que os motores X-Smart Plus, VDW.Silver e iRoot apresentaram baixa variação na velocidade rotacional quando comparada ao fornecido pelo fabricante. Os motores endodônticos apresentaram diferentes comportamentos entre eles, sendo que o motor VDW.Silver apresentou valores mais acurados enquanto o iRoot foi o mais divergente.

Application of intelligent robot system in teaching cervical spine manipulation / 国际生物医学工程杂志

Objective:To explore the application effect of an intelligent teaching robot system of lifting manipulation in cervical spine manipulation teaching.Methods:60 doctors were randomly divided into an experimental group ( n = 30) and a control group ( n = 30). The control group was taught by a certified chief physician using a combination of "PowerPoint presentations, video demonstrations, and operation demonstrations" . Each part is 5 min. The experimental group was taught by the intelligent teaching robot system with a spinning technique. The teaching time is 15 min for both groups. At the end of the two teaching sessions, the two groups were trained five times under different BMIs and passed the system assessment. The qualified rates of pre-traction force, lifting and pulling force, maximum force, pre-traction time, lifting and pulling time, rotation amplitude, and pitch amplitude were compared between the two groups. Results:In normal, there was significant differences between the qualified rates of pre-traction force, lifting and pulling force, maximum force, pre-traction time, lifting and pulling time, rotation amplitude, and pitch amplitude in two groups (all P<0.05). For overweight people, there were significant differences in pre-traction force, pulling force, maximum force, and rotation amplitude (all P <0.05), while there were no significant differences in pre-traction time, pulling time, or pitching amplitude (all P >0.05). In obesity, there were significant differences in pre-traction force, lifting and pulling force, maximum force, and pitch amplitude (all P <0.05), but no significant differences in pre-traction time, lifting and pulling time, or rotation amplitude (all P >0.05). Conclusions:The proposed system can improve the pass rate of spinning manipulation, especially by effectively controlling the pre-traction force, pulling force, and maximum force.

Automedicación por síntomas de COVID-19 en internos rotativos de Enfermería

Introducción: La automedicación puede generar reacciones adversas, interacciones medicamentosas, retraso y fallo en el diagnóstico de la enfermedad, resistencia a los antibióticos y pérdida de recursos sanitarios. Durante la pandemia por COVID-19 se reporta que la frecuencia de reacciones adversas por automedicación se ha duplicado. Objetivo: Identificar las diversas causas y factores que inciden en la automedicación por COVID-19 en internos rotativos de Enfermería, del Hospital General "Luis Gabriel Dávila" de Tulcán, Ecuador. Método: Se realizó un estudio transversal descriptivo-analítico-correlacional, sobre la automedicación en 64 internos rotativos de Enfermería de dicha institución en el periodo 2020-2021. Se utilizaron los métodos: del nivel empírico, analítico-sintético, inductivo-deductivo, histórico-lógico. El cuestionario fue la técnica aplicada para caracterizar el estado actual. Los datos recolectados se exportaron a Microsoft Excel v.2013. Resultados: El 50,3 % de los internos de Enfermería se medicaron de forma frecuente, el 60,9 % se automedicó con analgésicos ante la presencia de síntomas por COVID-19. El 29,7 % presentó dolor de garganta como sintomatología de COVID-19, seguido por fiebre con el 26, 5 %. El 78,1 % utilizó la vía oral. El 55,0 % de estos internos siempre tuvo libre acceso a los medicamentos en sus rotaciones; lo que incitó al 42,2 % a la automedicación. Conclusiones: Los resultados obtenidos sirven para caracterizar la problemática de la automedicación por COVID-19 en estudiantes universitarios y brindar información para el planteamiento de estrategias que reduzcan su impacto negativo. Las autoridades universitarias y sanitarias deben dedicar esfuerzos ante la problemática de la automedicación por COVID-19, dado que es un problema de salud pública a nivel mundial.

Introduction: Self-medication can generate adverse reactions, drug interactions, delay and failure in the diagnosis of the disease, resistance to antibiotics and loss of health resources. During the COVID-19 pandemic, it is reported that the frequency of adverse reactions due to self-medication has doubled. Objective: To identify the various causes and factors that affect self-medication by COVID-19 in rotating Nursing interns at the Hospital General "Luis Gabriel Dávila" in Tulcán, Ecuador. Method: A descriptive-analytical-correlational cross-sectional study was carried out on self-medication in 64 rotating Nursing interns of said institution in the period 2020-2021. Methods were used: empirical, analytical-synthetic, inductive-deductive, historical-logical level. The questionnaire was the technique applied to characterize the current state. The collected data was exported to Microsoft Excel v.2013. Results: 50.3% of Nursing inmates took frequent medication, 60.9% self-medicated with analgesics in the presence of symptoms due to COVID-19. 29.7% presented sore throat as a symptom of COVID-19, followed by fever with 26.5%. 78.1% used the oral route. 55.0% of these inmates always had free access to medications in their rotations; which prompted 42.2% to self-medication. Conclusions: The results obtained serve to characterize the problem of self-medication by COVID-19 in university students and provide information for the formulation of strategies that reduce its negative impact. The university and health authorities must dedicate efforts to the problem of self-medication by COVID-19, since it is a public health problem worldwide.

Introdução: A automedicação pode gerar reações adversas, interações medicamentosas, atraso e falha no diagnóstico da doença, resistência a antibióticos e perda de recursos de saúde. Durante a pandemia de COVID-19, foi relatado que a frequência de reações adversas devido à automedicação dobrou. Objetivo: Identificar as várias causas e fatores que afetam a automedicação por COVID-19 em internos de enfermagem rotativos no Hospital General "Luis Gabriel Dávila" em Tulcán, Equador. Método: Realizou-se um estudo transversal descritivo-analítico-correlacional sobre a automedicação em 64 internos rotativos de Enfermagem da referida instituição no período 2020-2021. Os métodos utilizados foram: nível empírico, analítico-sintético, indutivo-dedutivo, histórico-lógico. O questionário foi a técnica aplicada para caracterizar o estado atual. Os dados coletados foram exportados para o Microsoft Excel v.2013. Resultados: 50,3% dos reclusos de Enfermagem tomavam medicação frequente, 60,9% automedicavam-se com analgésicos na presença de sintomas devido à COVID-19. 29,7% apresentaram dor de garganta como sintoma de COVID-19, seguido de febre com 26,5%. 78,1% utilizaram a via oral. 55,0% desses internos sempre tiveram livre acesso a medicamentos em seus rodízios; o que levou 42,2% à automedicação. Conclusões: Os resultados obtidos servem para caracterizar o problema da automedicação por COVID-19 em estudantes universitários e fornecer informações para a formulação de estratégias que reduzam seu impacto negativo. A universidade e as autoridades de saúde devem dedicar esforços ao problema da automedicação por COVID-19, uma vez que é um problema de saúde pública mundial.

Comparison of obturation quality, instrumentation time and post-operative pain using manual K-files and pediatric rotary files in primary molars ­ a double blinded randomised clinical trial / Comparação da qualidade de obturação, tempo de instrumentação e dor pós-operatória usando Limas manuais K e Limas rotativas pediátricas em molares decíduos ­ um estudo clínico randomizado duplo-cego

Objective: to compare the quality of obturation, instrumentation time and post-operative pain after pulpectomy in primary molars using manual K-files, Kedo-S and Kedo-S Square rotary file systems. Material and Methods: a double blinded randomized control trial was conducted in 45 children, who were indicated for pulpectomy in any one of the primary mandibular molars. The canal preparation was done using either hand K-files, Kedo-S files, or Kedo-S Square files based on the groups assigned. The time taken for instrumentation was recorded using a stopwatch. The quality of obturation was evaluated using post-operative radiograph and post-operative pain was assessed with modified Wong-Baker Faces Pain scale. Results: instrumentation time was minimum in rotary Kedo-S Square files (53.23 ± 9.60 seconds) followed by Kedo-S files (82.70 ± 11.86 seconds). The preparation time was maximum with manual K-files (121.43 ± 20.18 seconds). Kedo-S square files provided a higher number of optimally filled canals (66.4%). All the three instrumentations equally showed the tendency to produce voids in the obturation. Rotary files Kedo-S Square followed by Kedo-S showed less post-operative pain compared to K-files. Conclusion: the use of pediatric rotary instruments for canal preparation during pulpectomy will result in better quality of obturation in reduced time with least post-operative pain (AU)

Objetivo: comparar a qualidade de obturação, tempo de instrumentação e dor pós-operatória após pulpectomia em molares decíduos usando limas manuais K, limas rotatórias Kedo-S e limas rotatórias Kedo-S Square. Material e Métodos: um estudo clínico randomizado duplo-cego foi conduzido com 45 crianças que foram submetidas à pulpectomia de algum molar decíduo indicado. A preparação do canal foi feita usando limas manuais K, ou limas Kedo-S, ou ainda Limas Kedo-S Square, com base nos grupos que foram selecionados. O tempo para a instrumentação foi registrado com um cronômetro. A qualidade de obturação foi avaliada por meio de uma radiografia após o procedimento e a dor pós-operatória foi avaliada com a escala de dor Wong-Baker Faces modificada. Resultados: o tempo de instrumentação foi mínimo para as limas rotatórias Kedo-S Square (53,23 ± 9,60 segundos) seguido pelas limas Kedo-S (82,70 ± 11,86 segundos). O tempo de preparação foi maior com as limas manuais K (121,43 ± 20,18 segundos). As limas Kedo-S Square promoveram um maior número de canais otimamente obturados (66,4%). Todas as três instrumentações mostraram igualmente a tendência em seproduzir vazios na obturação. As limas rotatórias Kedo-S Square seguidas pelas limas Kedo-S produziram menos dor pós-operatória comparadas às limas manuais K. Conclusão: o uso de instrumentos rotatórios pediátricos para a preparação do canal durante a pulpectomia resultará em melhor qualidade de obturação em tempo reduzido e com menos dor pós-operatória. (AU)

An in vitro comparative evaluation of dentinal crack formation caused by three different nickel–titanium rotary file systems in primary anterior teeth

Context: Cleaning and shaping of the canals damages the root dentin which becomes a gateway to dentinal cracks and thereby causes failure of the treatment. Aim: The aim of this study was to assess and compare dentinal crack formation caused by three different nickel–titanium (NiTi) rotary file systems in primary anterior teeth. Settings and Design: The present in vitro study is an experimental, comparative study. Materials and Methods: One hundred fifty extracted primary anterior teeth were included in this study. The teeth were randomly divided into five groups. Group 1: Pedoflex rotary file system, Group 2: Prime Pedo™ rotary file system, Group 3: Kedo-S2 rotary file system, Group 4: K-files, and Group 5: no instrumentation. Roots were sectioned and viewed under a stereomicroscope for the presence of any cracks. Statistical Analysis Used: The data were analyzed using the Chi-square test and Kruskal–Wallis test. Results: In the coronal, middle, and apical thirds, Group 2 showed a maximum number of crack formations in the middle third (57%), followed by Group 3 (43.3%) and Group 1 (36.7%). Groups 4 and 5 showed no crack formation in all the root sections. The middle third showed a maximum number of crack formations compared to the coronal and apical thirds. Conclusions: Rotary systems render various benefits with an acceptable success in comparison to conventional hand instrumentation. Within the limitation of this study, it was found that Pedoflex rotary file system was the best with the least number of crack formations.

Shaping Ability of Reciprocating and Rotary Systems After Root Canal Retreatment: a CBCT Study

Abstract The purpose of this in vitro study was to evaluate the shaping ability of reciprocating and continuous rotary systems after root canal retreatment. After preparation and root canal filling, mesial canals of 54 mandibular molars were distributed into 3 groups (n=18), according to the filling material removal and re-instrumentation protocols: WOG group - WaveOne Gold system; PTN group - ProTaper Next system; and PTU group - ProTaper Universal system. Cone-beam computed tomographic (CBCT) images acquisition of the mesial root canals was performed at different moments: (1) before instrumentation (unprepared root canals), (2) after preparation and filling, (3) after filling material removal and (4) re-instrumentation. The apical transportation (AT), centering ability (CA) and change in root canal diameter were assessed by CBCT analysis. The remaining filling material quantification was performed by radiographic examination. The statistical analyses were performed using the 3-way ANOVA, Tukey-Kramer, Kruskal-Wallis and Dunn multiple Comparison tests (p<0.05). The tested instruments did not show full CA (=1.0). PTN group had greater AT at the 5th mm in comparison with the WOG group (p<0.05). After re-instrumentation, WOG group had greater root canal diameter change at the 1st and 5th mm than PTN and PTU groups (p<0.05). There was no significant difference among groups when comparing the amount of remaining filling material after re-instrumentation (p>0.05). The tested systems provided minimal alteration in root canal morphology at the apical portion after root canal retreatment. However, WOG promoted greater change in root canal diameter.

Resumo O objetivo deste estudo in vitro foi avaliar a capacidade de modelagem de sistemas rotatórios e reciprocantes após o retratamento do canal radicular. Após o preparo e obturação do canal radicular, os canais mesiais de 54 molares inferiores foram distribuídos em 3 grupos, de acordo com os protocolos de remoção do material obturador e re-instrumentação: (n=18): grupo WOG - sistema WaveOne Gold; Grupo PTN - sistema ProTaper Next; e grupo PTU - sistema ProTaper Universal. A análise das imagens de tomografia computadorizada de feixe cônico foi realizada em diferentes momentos: (1) antes da instrumentação (canais radiculares não preparados), (2) após o preparo e obturação, (3) após a remoção do material obturador e (4) re-instrumentação. O transporte apical (TA), a capacidade de centralização (CC) e a mudança no diâmetro do canal radicular foram avaliados por análise tomográfica. A quantificação do restante do material obturador foi realizada por exame radiográfico. As análises estatísticas foram realizadas utilizando os testes de ANOVA de 3 fatores, Tukey-Kramer, Kruskal-Wallis e Comparações Múltiplas de Dunn (p<0,05). Os instrumentos não apresentaram CC perfeita (=1,0). PTN apresentou maior TA no 5º mm em comparação ao grupo WOG (p<0,05). Após a re-instrumentação, o grupo WOG apresentou maior aumento no diâmetro do canal radicular no 1° e 5° mm do que os grupos PTN e PTU. Não houve diferença significativa entre os grupos em relação à remoção do material obturador (p>0,05). Os sistemas testados proporcionaram alteração mínima na morfologia do canal radicular na porção apical após o retratamento do canal radicular. No entanto, WOG promoveu maior alteração no diâmetro do canal radicular.

Comparative evaluation of change in root canal shape and area in primary molars using ProTaper and K3 rotary systems In vitro study

Background: Rotary instrument techniques have shown evidence of simultaneously enlarging the root canal and maintaining the canal anatomy. Protocols for the use of rotary systems in primary molars are not well established. Aims: The aim of the study was to evaluate and compare root canal shape and area after ProTaper and K3 rotary instrumentation in primary molars. Settings and Design: Coronal access cavities with straight-line access into the root canals were prepared on primary mandibular molar teeth, extracted for therapeutic reasons. The teeth were aligned in a prefabricated template in individual self-cure acrylic blocks such that their respective positions could be reproduced later. Subject and Methods: Forty-two primary mandibular molar teeth selected were equally divided into three groups: instruments with stainless-steel (SS) hand K-files, ProTaper, and K3 Endo rotary system. Precomputed tomography (CT) slices were taken at predetermined levels (coronal, middle, and apical third) followed by instrumentation of canals using selected files and post-CT scan. Statistical Analysis Used: Data obtained were evaluated using independent t-test with a 0.05 level of significance and ANOVA. Results: SS hand K-files and rotary ProTaper and K3 Endo of 0.04 taper produced a predominantly round shape at coronal, middle, and apical levels. ProTaper system caused the greatest increase in round-shaped canals and canal area followed by K3 Endo of 0.04 taper. Conclusions: Shaping abilities of both manual and rotary instrumentation systems in primary molars were similar, whereas for enlarging and maintaining anatomy, rotary systems (ProTaper and K3) were better.

The effect of glide path preparation on the shaping ability of XP-endo® Shaper in simulated canals

Aims: To compare the shaping efficiency of the XP-endo Shaper with or without glide path preparation with sequenced Scout Race files in J-shaped resin blocks Material and Methods: Forty simulated J-shaped root canals were classified into two groups (n=20). While the root canals were shaped with XPS after a glide path was created with Scout Race files in Group 1, the same procedures were done without the glide path preparation in Group 2. The pre-and post-instrumentation images were taken and superimposed. Transportation value (TV), centering ability (CA) and the total amount of resin removed (TRR) was calculated by using the obtained images with Adobe Photoshop CS5 software. These parameters were calculated based on 18 reference points (9 inner/9 outer walls) with 1-mm intervals according to 3 sections (coronal, middle, and apical of the canals). The data were analyzed with Kruskal-Wallis and then Dunn's multiple comparison tests (p ≤ 0.05). Results: More resin was removed in Group 2 apical and coronal sections than in Group 1 (p=0.036). In Group 2, a higher transportation value was obtained in apical and middle sections compared to Group 1 (p<0.001). Group 1 showed a higher centering ratio in apical and middle sections than in Group 2 (p<0.001). The centering ability of the instruments was decreased in the curvature part (middle section) of the canals. Conclusions: Within the limits of this study, glide path preparation using Scout Race instruments improved the shaping ability of XPS instrument by leading to less transportation and maintaining centering ability.

Avaliação do nível de sujidade de sistemas rotatório e reciprocante após instrumentação e procedimentos de limpeza pré-esterilização / Evaluation of the dirt level of rotary and reciprocating systems after instrumentation and pre-sterilization cleaning procedures

Objetivos: avaliar a sujidade de limas rotatórias e reciprocantes após instrumentação e procedimentos de limpeza pré-esterilização. Materiais e métodos: 24 limas rotatórias e as 24 limas reciprocantes foram divididas, aleatoriamente, em dois grandes grupos. No primeiro grupo, as 12 limas rotatórias e as 12 limas reciprocantes foram divididas, aleatoriamente, em seis subgrupos (SG): SG1 (controle negativo 1/n=1) ­ 1 lima rotatória não submetida à instrumentação; SG2 (controle negativo 2/n=1) ­ 1 lima reciprocante não submetida à instrumentação; SG3 (controle positivo 1/n=1) ­ 1 lima rotatória submetida à instrumentação e não submetida a qualquer protocolo de limpeza; SG4 (controle positivo 2/n=1) ­ 1 lima reciprocante submetida à instrumentação e não submetida a qualquer protocolo de limpeza; SG5 (grupo teste/n=10) ­ 10 limas rotatórias submetidas à instrumentação e submetidas ao protocolo de lavagem manual; SG6 (grupo teste/ n=10) ­ 10 limas reciprocantes submetidas à instrumentação e submetidas ao protocolo de lavagem manual. No segundo grupo, as 12 limas rotatórias e as 12 limas reciprocantes foram divididas, aleatoriamente, nos mesmos subgrupos, substituindo, nos subgrupos 5 e 6, a lavagem manual pela lavagem em cuba ultrassônica. A análise do nível de sujidade foi realizada por microscopia eletrônica de varredura (MEV), sendo os dados submetidos ao teste de Kruskal-Wallis, com nível de significância de 5%. Resultados: a menor média de sujidade entre os grupos experimentais foi encontrada no SG5 do G1, sem diferença significante em relação aos demais grupos testados (p>0,05). Conclusão: conclui-se que os protocolos de limpeza testados não foram completamente efetivos para a remoção de sujidade das limas endodônticas.(AU)

Objective: to evaluate the dirt of rotary and reciprocating files after instrumentation and pre- -sterilization cleaning procedures. Materials and Methods: 24 rotary files and the 24 reciprocating files were randomly divided into two groups. In the 1st group, 12 rotary files and 12 reciprocating files were randomly divided into six subgroups (SG): SG1 (negative control 1/n=1) ­ 1 rotary file not subjected to instrumentation; SG2 (negative control 2/n=1) ­ 1 reciprocating file not subjected to instrumentation; SG3 (positive control 1/n=1) ­ 1 rotary file submitted to instrumentation and not submitted to any cleaning protocol; SG4 (positive control 2/n=1) ­ 1 reciprocating file submitted to instrumentation and not submitted to any cleaning protocol; SG5 (test group/n=10) ­ 10 rotary files submitted to instrumentation and submitted to the manual cleaning protocol; SG6 (test group/n=10) ­ 10 reciprocating files submitted to instrumentation and submitted to the manual cleaning protocol. In the 2nd group, the 12 rotary files and the 12 reciprocating files were randomly divided into the same subgroups, substituting, in subgroups 5 and 6, manual with ultrasonic bath cleaning. The analysis of dirt levels was performed by scanning electron microscopy (SEM), being the data submitted to the Kruskal-Wallis test, with a significance level of 5%. Results: the lowest average of dirt between the experimental groups was found in SG5 of G1, with no significant difference when compared to the other groups (p>0.05). Conclusion: it could be concluded that the cleaning protocols were not completely effective in removing dirt from endodontic files.(AU)

Análisis Elemental de las Propiedades Morfológicas, Físicas y Químicas de Dos Instrumentos Rotatorios Protaper Universal

RESUMEN: Los instrumentos rotatorios utilizados en el tratamiento de conductos dentales necesitan cumplir con ciertas características físicas que le confieran un uso correcto, adecuado y seguro para su uso clínico. En el mercado comercial existen una serie de instrumentos importados que dejan en duda la autenticidad de estos debido a sus bajos costos. En este estudio evaluamos física, química y morfológicamente dos kits de instrumentos rotatorios Protaper universal (Dentsply) mediante análisis de MEB, EDX, microdureza y EDS. Uno de los kits (grupo 1) se adquirió directamente de la casa comercial y otro kit importado que a simple vista no parecía cumplir con los estándares de calidad de un correcto empaquetado (grupo 2). En el análisis de MEB se observaron características morfológicas muy diferentes entre ambos kits, el grupo 2 presentó diversas irregularidades en la superficie de las limas, sin embargo, en el EDS no se encontró diferencia alguna. En cuanto al análisis de microdureza se observó una estadística estadísticamente significativa y en el EDS se observaron mayores picos de intensidad en cuanto a la aleación de Ni-Ti en el grupo 2. Estos resultados sugieren que existen instrumentos rotatorios importados que a pesar de su bajo costo pueden presentar ciertas características muy similares a los kits auténticos, sin embargo, física y químicamente pueden resultar en un riesgo para su uso clínico debido a la diferencia entre estos.

ABSTRACT: Rotatory files are instruments used in the treatment of dental canals roots. These instruments need to comply with certain physical characteristics for a correct, adequate and safe use for clinical use. In the commercial market there are a series of imported instruments that cast doubt on their authenticity due to their low costs. In this study we physically, chemically and morphologically evaluated two Protaper universal rotary instrument kits (Dentsply) using SEM, EDX, microhardness and EDS analysis. One of the kits (group 1) was purchased directly from the commercial house and another imported kit that a simple view did not seem to meet the quality standards of a correct packaging (group 2). In the SEM analysis, very different morphological characteristics were observed between both kits, group 2 presented various irregularities on the surface of the files, however, no difference was found in the EDS. Regarding the microhardness analysis, a statistically significant statistic was observed and in the EDS, higher intensity peaks were observed in terms of the Ni-Ti alloy in group 2. These results suggest that there are imported rotary instruments that despite their low cost can present characteristics very similar to authentic kits, however, physically and chemically they can result in a risk for their clinical use due to the difference between them.

Instrumentación rotatoria comparado con instrumentación manual para tratamiento endodóntico en dientes permanentes / Rotary instrumentation compared to manual instrumentation for endodontic treatment in permanent teeth

RESUMEN: Introducción: El éxito del tratamiento endodóntico requiere de la desinfección completa del sistema de canales radiculares. Convencionalmente este procedimiento se realiza a través de maniobras de instrumentación rotatoria o manual e irrigación química. Dentro de las diferentes técnicas de instrumentación, la de tipo rotatoria ha surgido como una alternativa a la instrumentación manual, cuyos beneficios en comparación a ésta aún deben ser dilucidados. Métodos: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. Resultados y conclusiones: Identificamos cinco revisiones sistemáticas que en conjunto incluyeron 15 estudios primarios, de los cuales, 10 corresponden a ensayos aleatorizados. Concluimos que el uso de instrumentación rotatoria en comparación a instrumentación manual probablemente disminuye la incidencia del dolor postoperatorio. Además, la instrumentación rotatoria podría disminuir el uso de analgésicos post tratamiento endodóntico. Sin embargo, podría resultar en poca o nula diferencia en la intensidad del dolor, pero la certeza de la evidencia es baja. Además, no es posible establecer con claridad si el uso de instrumentación rotatoria en comparación a la instrumentación manual aumenta la reparación apical debido a que la certeza de la evidencia existente ha sido evaluada como muy baja.

ABSTRACT: Introduction: Successful root canal therapy (endodontic treatment) requires complete disinfection of the root canal system. Traditionally, disinfection of the root canal system involves rotary or manual instrumentation and chemical irrigation. Various rotary instrumentation techniques have emerged as an alternative to manual instrumentation, but its benefits against manual techniques need to be clarified. Methods: We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. Results and conclusions: We identified five systematic reviews that together included 15 primary studies, of which 10 correspond to randomized trials. We conclude that the use of rotary instrumentation compared to manual instrumentation probably reduces the incidence of pain. Also, rotatory instrumentation may reduce the use of postoperative analgesics. However, it could result in little or no difference in pain intensity, but the certainty of the evidence is low. Furthermore, it is not possible to clearly establish whether the use of rotary instrumentation increases apical repair as the certainty of the evidence has been assessed as very low.

Ultrasound-guided minimally invasive mammotomy versus conventional surgery for benign breast tumors / 中国基层医药

Objective:To investigate the clinical efficacy of ultrasound-guided mammotomy versus conventional surgery in the treatment of benign breast tumors. Methods:Sixty patients with benign breast tumors who received treatment in Jiamusi Central Hospital from September 2018 to September 2019 were included in this study. They were randomly assigned to undergo either conventional surgery (control group, n = 30) or ultrasound-guided mammotomy (treatment group, n = 30). Intraoperative blood loss, operative time, incision length, and the incidence of complications were compared between the two groups. Results:Intraoperative blood loss, operative time, and incision length in the treatment group were (4.25 ± 1.23) mL, (15.36 ± 3.21) minutes, (0.41 ± 0.05) cm, respectively, which were significantly lower or shorter than those in the control group [(10.75 ± 2.12) mL, (29.68 ± 7.23) minutes, (2.9 ± 0.8) cm, t = 14.526, 9.915, 17.015, all P < 0.05]. In the treatment group, the incidence of complications was 3.33% (local hematoma n = 1, skin depression n = 0, flap necrosis n = 0, postoperative bleeding n = 0), which was significantly lower that 23.00% in the control group (local hematoma n = 2, skin depression n = 1, flap necrosis n = 1, postoperative bleeding n = 3, χ2 = 5.192, P < 0.05). Conclusion:Compared with the traditional treatment, ultrasound-guided minimally invasive mastectomy is more effective in the treatment of benign breast tumors.

In Vitro Evaluation of a Recently Developed Rotary File: AF Rotary / Avaliação in vitro de um arquivo rotativo desenvolvido recentemente: AF Rotary

Objective: Aim of the present study is to evaluate mechanical properties of a newly developed rotary file, AF Rotary (Fanta Dental, Shanghai, China), and to compare these features with a worldwide spread rotary file, Protaper Gold F2 (PTG F2; Dentsply Maillefer, Ballaigues, Switzerland). Material and Methods: 60 AF Rotary 25.06 and 60 PTG F2 were divided in three groups of 20 files each. A group underwent to cyclic fatigue resistance tests, second group underwent to torsional resistance tests, third group underwent to bending tests. The statistical analysis was performed using t student test with significance level set at 95% (p < 0.05). Results: AF Rotary showed significantly higher torsional resistance and cyclic fatigue resistance (p < 0.05) when compared to the PTG F2. AF Rotary also showed significantly lower bending resistance (p < 0.05) when compared to the PTG F2. Conclusion: Therefore, within the limitations of this study, the results show better performances for AF Rotary compared to PTG F2 regarding the cyclic fatigue test, the torsional test and the bending test. Since the PTG F2 is a commonly used and widely investigated instrument it could be possible to state that the AF Rotary exhibits remarkable in vitro performances. (AU)

Objetivo: O objetivo do presente estudo é avaliar as propriedades mecânicas de uma lima rotativa recém-desenvolvida, AF Rotary (Fanta Dental, Shanghai, China), e comparar essas características com uma lima rotativa mundialmente difundida, Protaper Gold F2 (PTG F2; Dentsply Maillefer, Ballaigues, Suíça). Material e Métodos: 60 AF Rotary 25.06 e 60 PTG F2 foram divididos em três grupos de 20 arquivos cada. Um grupo foi submetido a testes de resistência à fadiga cíclica, o segundo grupo foi submetido a testes de resistência à torção, o terceiro grupo foi submetido a testes de flexão. A análise estatística foi realizada por meio do teste t student com nível de significância de 95% (p <0,05). Resultados: AF Rotary apresentou resistência torcional e resistência à fadiga cíclica significativamente maiores (p <0,05) quando comparado ao PTG F2. AF Rotary também apresentou resistência à flexão significativamente menor (p <0,05) quando comparado ao PTG F2. Conclusão: Portanto, dentro das limitações deste estudo, os resultados mostram melhores desempenhos do AF Rotary em relação ao PTG F2 no que diz respeito ao teste de fadiga cíclica, ao teste de torção e ao teste de flexão. Uma vez que o PTG F2 é um instrumento comumente usado e amplamente investigado, pode-se afirmar que o AF Rotary exibe desempenhos in vitro notáveis. (AU)

Evaluation of Apical Transportation by Three Rotary Systems in Extracted Teeth with Curved Canals / Evaluación de la transportación apical con tres sistemas rotatorios en dientes extraídos con conductos curvos

Abstract The aim of this study was to compare the apical transportation in extracted teeth using three different rotary nickel-titanium systems (Mtwo, Hyflex CM, and Typhoon). Sixty extracted first molars were randomly divided into three groups (n=20 in each group) with similar root canal curvatures (25-52 degrees). All root canals were prepared to size 30 using a crown-down preparation technique for each rotary system. Loss of working length and apical transportation were determined by X-ray evaluation. Comparisons between the groups were performed using one-way analysis of variance (ANOVA) or Kruskal-Wallis tests, and the post hoc analyses employed were Dunn´s or Tukey´s multiple comparison tests. No significant differences were detected between the different rotary systems in the loss of working length and apical transportation. This in vitro study showed that the use of these three rotary systems are safe and useful for instrumentation in curved canals; however, further in vivo research is essential to compare the effectiveness and safety of these systems for use in curved canals.

Resumen El objetivo del presente estudio fue comparar la transportación apical en dientes extraídos utilizando tres sistemas rotatorios de níquel-titanio (Mtwo, Hyflex CM y Typhoon). Sesenta primeros molares extraídos se dividieron aleatoriamente en tres grupos (n=20 en cada grupo) con curvaturas del conducto radicular similares (25-52 grados). Todos los conductos radiculares se prepararon usando una técnica corono apical para cada sistema rotatorio. La pérdida de la longitud de trabajo y la transportación apical se determinaron mediante evaluación radiográfica. Las comparaciones entre los grupos se realizaron utilizando análisis de varianza de una vía (ANOVA) o Kruskal-Wallis, y los análisis post hoc empleados fueron las pruebas de comparación múltiple de Dunn o Tukey. No se detectaron diferencias significativas entre los diferentes sistemas rotatorios en la pérdida de la longitud de trabajo y transportación apical. Este estudio demostró que el uso de estos tres sistemas es seguro y útil para su instrumentación en conductos curvos; sin embargo, investigación in vivo es necesaria para comparar la efectividad y seguridad de estos sistemas para su uso en conductos curvos.

La Asociación Médica Argentina y el Rotary Club de Buenos Aires. La misión rotaria y su relación con la medicina / The Argentine Medical Association and the Rotary Club of Buenos Aires. The rotary mission and its relationship with medicine

Con motivo del centenario del Rotary Club de Buenos Aires (RCBA), se describe su relación con la también centenaria Asociación Médica Argentina (AMA), a través de personalidades que pertenecieron a ambas entidades. Reseñamos la misión rotaria y su relación con la medicina. (AU)

On the occasion of the centenary of the Rotary Club of Buenos Aires (RCBA), its relationship with the also centennial Argentine Medical Association (AMA) is described, through personalities that belonged to both entities. A review of the Rotary mission and its relationship with medicine is made. (AU)

Design of Multimodality Wheelchair Based on Double Parallelogram Mechanism / 中国康复理论与实践

Objective:To design a multimodality wheelchair in order to meet many use requirements of the lower limbs dyskinesia patients. Methods:For some shortcomings of the existing multimodality wheelchair such as heavy structure and drive redundancy, the design of multimodality wheelchair based on double parallelogram mechanism is studied, and a simple and reliable multimodality wheelchair mechanism is presented. Rotary actuation drives the double parallelogram mechanism and makes parts of the wheelchair move, and three posture transformations are realized. The coupling movement of the back and leg rest realizes the transformation of sitting and supine posture, and the coupling movement of seat and back realizes the change of sitting and standing posture. The mechanical analysis of wheelchairs based on uniform load was carried out, and the rotation moment is calculated. Results:When the driving torque changed from sitting position to supine position, it increased with the increase of rotation angle and reached a peak value. When the driving torque changed from sitting position to standing position, it gradually decreased with the increase of rotation angle. Then the dynamics simulation is carried out in Adams software, the calculated results were basically consistent with the simulation results. Conclusion:The proposed mechanism is helpful to realize the lightweight design of multimodality wheelchair, and meets the design needs of intelligent multimodality wheelchair.

Assessing the quality of root canal filling and instrumentation time using kedo-s files, reciprocating files and k-files / Avaliando a qualidade de obturação e tempo instrumentação usando limas kedo-s, limas reciprocantes e limas k manuais

Objective: Pulpectomy is the conservative treatment approach that retains and preserves the primary tooth in the dental arch in its normal function and non-pathologic state until its exfoliation. Over the years, pulpectomy has been performed using various instrumentation techniques. The aim of this study was to compare the quality of root filing and instrumentation time using Kedo-S files, Reciprocating files and K-files in primary teeth. Material And Methods: A randomized clinical trial was performed on 45 primary molars equally distributed for instrumentation with Kedo-S files, reciprocating files and K-Files. Immediate post-operative digital radiographs were taken to evaluate the quality of root filing and root canal instrumentation time was also recorded. Results: Mean instrumentation time with Kedo-S was 75.6 seconds, reciprocating file was 190.6 seconds and K-file was 95.4 seconds. Highest optimal fill was obtained with Kedo-S file group, highest overfill was obtained with Kedo-S group and highest under fill was obtained with reciprocating file group. Conclusion: Kedo-S rotary system provides better quality of root canal filling in minimum instrumentation time. (AU)

Objetivo: A pulpectomia é o tratamento conservador que retém e preserva o dente decíduo na arcada dentária em sua função normal e estado não patológico até sua esfoliação. Ao longo dos anos, a pulpectomia foi realizada usando várias técnicas de instrumentação. O objetivo deste estudo foi comparar a qualidade da obturação do canal radicular e do tempo de instrumentação usando limas Kedo-S, limas reciprocantes e limas K em dentes decíduos. Material e Métodos: Foi realizado um ensaio clínico randomizado em 45 molares decíduos distribuídos igualmente para instrumentação com limas Kedo-S, limas reciprocantes e limas K. Radiografias digitais pós-operatórias imediatas foram realizadas para avaliar a qualidade da obturação e também foi registrado o tempo de instrumentação do canal radicular. Resultados: O tempo médio de instrumentação com Kedo-S foi de 75,6 segundos, com limas reciprocantes foi de 190,6 segundos e com limas K foi de 95,4 segundos. O maior índice de obturação ideal foi obtido com o grupo de limas Kedo-S, o maior índice de sobreobturação foi obtido com o grupo Kedo-S e o maior índice de infraobturação foi obtido com o grupo de limas reciprocantes. Conclusão: O sistema rotatório Kedo-S fornece melhor qualidade de obturação do canal radicular em tempo mínimo de instrumentação.(AU)

Comparative Evaluation of Mechanical Failure of Different Rotary Endodontic Files: An SEM Study

Conventional endodontic instruments make the intracanalprocedures versatile with more efficiency and minimumcomplication. The development of microfractures in the I-RaCeNickel-Titanium rotary (NTR) file and ProFile NTR file wasevaluated by using Scanning electron microscopy (SEM).Thirty six maxillary buccal roots and thirty six mandibularmesial roots with an average canal curvature of 37° wereassigned to each group and prepared with 21mm, 0.04 taperNTR files as follows: (1) I-RaCe (2) ProFile. File sizes 0.06 to0.04 were used in a crown-down technique to a master apicalfile (MAF) size of 0.04/25. The MAF instruments wereevaluated by SEM before use, after completion of 7 canals,and after completion of 14 canals. All I-RaCe instrumentsdeveloped microfrcatures by the seven canal evaluation. TheProFile instruments showed no microfrctures at the 7-or-14canal evaluations. I-RaCe files separated at a higher rate thanProFile instruments. Under the conditions of this study, uniquefile design and electropolishing did not inhibit the developmentof microfractures in I-RaCe NTR.