Elaboração e avaliação de um instrumento de qualidade de vida para avaliar mucosite oral em pacientes oncológicos / Development and evaluation of a quality of life instrument to evaluate oral mucositis in cancer patients

Introdução: Mucosite oral é um efeito colateral dos tratamentos oncológicos, caracterizado por lesões orais que vão de eritema a úlceras que podem causar dor intensa e restrição de dieta. É conhecida como condição limitante e de grande impacto na qualidade de vida (QV). Objetivo: Elaborar um novo instrumento para avaliar a QV relacionada à mucosite oral. Material e método: Pesquisa através de métodos mistos, iniciando com entrevistas qualitativas analisadas pelo método de Bardin e método Reinert, com o programa IRAMUTEQ, seguido do método Delphi com quatro rodas de entrevistas e discussões com especialistas. A primeira versão do instrumento passou por um pré-teste com 10 pacientes, com análise quantitativa e qualitativa, seguido de outra rodada de especialistas. Resultados: O material das entrevistas qualitativas apontou os termos dor e alimentação como centrais na experiência de mucosite oral, além de fornecerem várias palavras-chave para definição dos constructos. Baseado nesse material e na literatura, 4 especialistas formularam 34 perguntas enviadas para outros 10 especialistas de diferentes regiões e instituições brasileiras que analisaram a clareza, ortografia e necessidade de cada pergunta para o questionário. As alterações pertinentes foram realizadas, revisadas e novamente discutidas. A primeira versão foi apresentada a 10 pacientes que não participaram das entrevistas qualitativas e responderam o grau de entendimento e necessidade de cada pergunta. A análise final do pré-teste reformulou alguns tempos verbais e palavras de difícil compreensão, dando forma a versão final do instrumento. Discussão: Embora existam bons instrumentos para mensurar QV e mucosite oral, apresentamos novas questões sobre impactos financeiros, interrupção de tratamento, alteração de saliva, perda de peso relacionada diretamente com a mucosite oral e aspectos psicossociais. Conclusão: Foi elaborado um novo instrumento para mensurar os impactos mucosite oral em pacientes oncológicos.

Influence of surgical instrument identifiers on microbial contamination of scalpel handles after cleaning and sterilization / Influencia de los identificadores de instrumental quirúrgicos en la contaminación microbiana de mangos para cuchillas de bisturí después de la limpieza y esterilización / Influência dos identificadores de instrumental cirúrgico na contaminação microbiana de cabos para lâminas de bisturi após limpeza e esterilização

Objective: To evaluate the influence of different instrument identifiers on the microbial growth of critical devices after cleaning and steriliza-tion steps. Method: Fifteen No. 3 scalpel handles were used as test specimens, divided into 3 groups (n=5), with each group consisting of an instrument without an identifier and four other instruments with the following identifiers: laser engraving, silicone ring, vinyl identifier with permanent adhesive and personalized adhesive label. After being submerged in the surgical aspirate, the instruments were processed in accordance with the good practice requirements of Resolution No. 15/2012 from the National Health Surveillance Agency (Anvisa). Microbial growth was evaluated at different times qual-itatively, by the presence or absence of growth, and quantitatively for positive cases, by counting viable colony-forming units (log CFU/scalpel handle). Results: At some point, there was microbial growth on the instruments regardless of the type of identifier. However, there was no continuous and pro-gressive contamination after repeating the cleaning and sterilization steps. Conclusion: The type of dental instrument identifier does not interfere with microbial growth as long as cleaning and sterilization standards are respected. (AU)

Objetivo: Evaluar la influencia de los diferentes identificadores de instrumental en el crecimiento microbiano de dispositivos críticos después de las etapas de limpieza y esterilización. Método: Se utilizaron 15 mangos #3 para cuchillas de bisturí como cuerpo de prueba, divididos en 3 grupos (n=5), cada grupo compuesto por un instrumental sin identificador y otros cuatro instrumentales con los siguientes identificadores: grabado a láser, ani-llo de silicona, identificador vinílico con adhesivo permanente y etiqueta adhesiva personalizada. Después de ser sumergidos en el aspirado quirúrgico, los instrumentales fueron procesados de acuerdo con los requisitos de buenas prácticas de la Resolución nº 15/2012 de la Agencia Nacional de Vigilancia Sanitaria (Anvisa). El crecimiento microbiano se evaluó en diferentes momentos de forma cualitativa, por la presencia o ausencia de crecimiento, y de forma cuantitativa para los casos positivos, mediante el recuento de unidades formadoras de colonias viables (log UFC/mango de bisturí). Resultados: En algún momento, hubo crecimiento microbiano en los instrumentales independientemente del tipo de identificador. Sin embargo, no hubo contaminación con-tinua y progresiva después de la repetición de las etapas de limpieza y esterilización. Conclusión: El tipo de identificador de instrumental odontológico no interfiere en el crecimiento microbiano siempre que se respeten las normas de limpieza y esterilización. (AU)

Objetivo: Avaliar a influência dos diferentes identificadores de instrumental no crescimento microbiano de dispositivos críticos após etapas de limpeza e esterilização. Método: Foram utilizados 15 cabos no 3 para lâminas de bisturi como corpo de prova, divididos em 3 grupos (n=5), sendo cada grupo composto de um instrumental sem identificador e outros quatro instrumentais com os seguintes identificadores: gravação a laser, anel de silicone, identificador vinílico com adesivo permanente e etiqueta adesiva personalizada. Após serem submersos no aspirado cirúrgico, os instrumentais foram processados de acordo com os requisitos de boas práticas da Resolução n. 15/2012 da Agência Nacional de Vigilância Sanitária (Anvisa). O crescimento microbiano foi avaliado em diferentes momentos de forma qualitativa, pela presença ou ausência de crescimento, e de forma quantitativa para os casos positivos, por meio de contagem de unidades formadoras de colônia viáveis (log UFC/cabo de bisturi). Resultados: Em algum momento, houve cres-cimento microbiano nos instrumentais independentemente do tipo de identificador. No entanto, não houve contaminação contínua e progressiva após repetição das etapas de limpeza e esterilização. Conclusão: O tipo de identificador de instrumental odontológico não interfere no crescimento micro-biano desde que sejam respeitadas as normas de limpeza e esterilização. (AU)

Evaluation of different methods of calcium hydroxide removal from root canals with simulated internal resorptions / Avaliação de diferentes métodos de remoção de hidróxido de cálcio de canais radiculares com reabsorções internas simuladas

Objective: This study evaluated different methods of calcium hydroxide (CH) removal from root canals with simulated internal resorptions using microcomputed tomography (micro-CT). Material and Methods: Sixty acrylic resin blocks with simulated root canals and internal resorptions were prepared using a Reciproc R25 file and then filled with CH. The blocks were divided into five test groups (n=12) according to the method used for CH removal: hand files (HF), Easy Clean (EC), passive ultrasonic irrigation (PUI), XP-Endo Finisher (XP), XP-Endo Finisher + PUI (XP+PUI). The blocks were scanned using a SkyScan 1172 scanner before and after CH removal to measure the volume and percentage of CH removal. The OriginPro 2017 software was used for statistical analyses. The level of significance was set at p<0.05 for all tests. Results: No method under study removed all CH. All methods had similar results in the cervical third (P>0.05). The percentage of CH removal was significantly greater in the area of internal resorption and along the total length of the canal in the XP+PUI group (P<0.05). The best results of CH removal were found in the apical third of roots in the XP+PUI and PUI groups (P>0.05). Conclusion: No method removed all CH from the root canals, but the combined XP+PUI method removed more CH than the other methods, especially from the area of the internal resorption(AU)

Objetivo: Este estudo avaliou diferentes métodos de remoção de hidróxido de cálcio (CH) de canais radiculares com reabsorções internas simuladas por meio de microtomografia computadorizada (micro-CT). Material e Métodos: Sessenta blocos de resina acrílica com canais radiculares simulados e reabsorções internas foram preparados com lima Reciproc R25 e posteriormente preenchidos com CH. Os blocos foram divididos em cinco grupos de teste (n=12) de acordo com o método utilizado para remoção de CH: limas manuais (HF), Easy Clean (EC), irrigação ultrassônica passiva (PUI), XP-Endo Finisher (XP), XP -Endo Finalizador + PUI (XP + PUI). Os blocos foram escaneados usando um scanner SkyScan 1172 antes e depois da remoção do CH para medir o volume e a porcentagem de remoção do CH. O software OriginPro 2017 foi utilizado para análises estatísticas. O nível de significância foi estabelecido em p<0,05 para todos os testes. Resultados: Nenhum método em estudo removeu todos o CH. Todos os métodos tiveram resultados semelhantes no terço cervical (P>0,05). A porcentagem de remoção de CH foi significativamente maior na área de reabsorção interna e ao longo do comprimento total do canal no grupo XP+PUI (P<0,05). Os melhores resultados de remoção de CH foram encontrados no terço apical das raízes nos grupos XP+PUI e PUI (P>0,05). Conclusão: Nenhum método removeu todo o CH dos canais radiculares, mas o método combinado XP+PUI removeu significativamente mais CH do que os outros métodos, especialmente da área de reabsorção interna (AU)

BlueShaper: un nuevo sistema multialeación para la instrumentación mecanizada en endodoncia: comunicación breve / BlueShaper: a new multialloy system for mechanized instrumentation in endodontics: brief communication

El objetivo de esta comunicación es describir y analizar el sistema BlueShaper para la preparación quirúrgica mecaniza- da de los conductos radiculares. El sistema dispone de un set básico de 4 limas: Z1, Z2, Z3 y Z4, con un D0 de 0,14 mm, 0,17 mm, 0,19 mm y 0,25 mm respectivamente y conicidad variable que oscila entre el 2 y 10 %. La lima Z1 posee una aleación Pink, que le confiere mayor resistencia a la torsión y una gran capacidad de corte. Las limas Z2, Z3 y Z4 presentan una aleación Blue que aumenta la resistencia a la fatiga cíclica e incrementa su flexibilidad. Para conductos radiculares más amplios se incluyen, además, las limas Z5, Z6 y Z7. La empresa comer- cializa conos de gutapercha BlueShaper que se corresponden con las limas Z3, Z4, Z5, Z6 y Z7. El sistema de limas mul- tialeación Blue Shaper podría considerarse como un nuevo aporte clínico para la preparación mecánica de los conductos radiculares (AU)

The aim of this communication was to describe and analyze the BlueShaper system for the mechanized surgical preparation of root canals. The system has a basic set of 4 files: Z1, Z2, Z3 and Z4, with 0.14 mm, 0.17 mm, 0.19 mm and 0.25 mm DO respective- ly, and variable conicity ranging between 2 and 10 %. Z1 file has a Pink alloy, which gives it greater resistance to torsion and great cutting capacity. The Z2, Z3 and Z4 files feature a Blue alloy that increases resistance to cyclic fatigue and increases their flexibility. For larger root canals, the Z5, Z6 and Z7 files are also included. The company supplies specific BlueShaper ́s gutta-percha cones for Z3, Z4, Z5, Z6 and Z7 files. The BlueShaper multialloy file system could be consid- ered as a new clinical contribution for the mechanical prepa- ration of root canals (AU)

Bypass de instrumento endodôntico fraturado: relato de caso / Bypass of a fractured endodontic instrument: case report

Introdução: Mesmo com toda evolução tecnológica desses instrumentos, com o desenvolvimento das limas de liga de níquel-titanio (NiTi) e sistemas mecanizados, as fraturas podem ocorrer durante o preparo químico/mecânico. Existem três abordagens mais regulamente aplicadas para solucionar essa intercorrencia: tentativa de remoção do instrumento com ultrassom, tentativa de ultrapassálo (bypass) ou a obturação do segmento. Objetivo: Relatar um caso da técnica de bypass em instrumento fraturado no canal radicular. Descrição do caso: Paciente, sexo feminino, 47 anos, brasileira, sem condições sistêmicas associadas, foi encaminhada à clínica do Curso de Odontologia da UNIFENAS, Divinópolis, Minas Gerais, Brasil, para resolução de fratura de instrumento no canal mésio- vestibular do primeiro molar superior direito (16). Optou-se pelo tratamento pela técnica de bypass, que envolveu as seguintes etapas: anestesia, abertura, utilização de lima C-Pilot #08 para ultrapassar o instrumento fraturado, odontometria, escalonamento regressivo a partir da lima k#20, desinfecção com hipoclorito de sódio 5%, medicação com hidróxido de cálcio por 21 dias, agitação da substância irrigadora e obturação dos canais radiculares. Conclusão: O bypass ao instrumento é uma técnica conservadora, eficaz e uma solução adequada em casos de fratura de limas endodônticas dentro dos canais radiculares. Essa técnica visa preservar o máximo possível da estrutura dental original, evitando procedimentos mais invasivos.(AU)

Introduction: Even with all technological evolution of these instruments, with the development of nickel-titanium alloy (NiTi) files and mechanized systems, fractures can occur during chemical/mechanical preparation. There are three most commonly applie to resolve this complication: attempting to remove the instrument with ultrasound, attempting to bypass it, or obturating the segment. Objective: To report a case of bypass technique in fractured instrument in the root canal. Case description: A 47-year-old female patient from Brazil, with no associated systemic conditions, was referred to the clinic of the Dentistry Course at UNIFENAS, Divinópolis, Minas Gerais, Brazil, for resolution of an instrument fracture in the mesio-vestibular canal of the right upper first molar (16). Treatment was performed using the bypass technique, which involved the following steps: anesthesia, opening, use of a C-Pilot #08 file to bypass the fractured instrument, odontometry, regressive scaling from the k#20 file, disinfection with 5% sodium hypochlorite, medication with calcium hydroxide for 21 days, agitation of the irrigating substance and root canal filling. Conclusion: Instrument bypass is a conservative, effective technique and an adequate solution in cases of endodontic file fracture within root canals. This technique aims to preserve as much of the original tooth structure as possible, avoiding more invasive procedures.(AU)

Processo de esterilização de materiais odontológicos: avaliação padronização em tempos de pandemia de Covid-19 / Process of sterilization of dental materials: evaluation and standardization in times of the covid-19 pandemic

Objetivos: avaliar os processos de coleta, lavagem e esterilização de instrumentais odontológicos, evidenciando se houveram mudanças no processo em função da pandemia de COVID-19, em consultórios odontológicos tanto particulares como públicos, na cidade de Pelotas-RS, visando auxiliar no incremento da segurança e eficácia da esterilização na prática odontológica, após uma crise sanitária global e propor um Procedimento Operacional Padrão (POP). Métodos: os dados foram obtidos em um único momento através de respostas dadas pela aplicação de um questionário para o profissional responsável pelo processo de esterilização de cada local. Os dados foram compilados pelo software Microsoft Excel, foi realizada a análise descritiva e os mesmos foram expressos na forma de porcentagem. Resultados: em 100% dos locais o processo de lavagem e esterilização ocorria na mesma sala de atendimento, destes em quatro locais a operação de transporte era realizada com o auxílio de uma caixa plástica higienizável e seis locais contavam com um processo de pré-lavagem. Todos os locais faziam uso de autoclave para o processo de esterilização, 100% realizavam o monitoramento químico do processo, porém apenas quatro realizavam o monitoramento biológico. Conclusão: houve poucas mudanças nos processos de lavagem e esterilização nos locais pesquisados em razão do surgimento da pandemia de COVID -19. Nenhum local examinado possuía o POP descrito do processo de lavagem e esterilização de instrumentais odontológicos e observou-se um baixo uso dos indicadores biológicos, os quais são considerados o padrão ouro da biossegurança.(AU)

Objectives: to evaluate the processes of collection, washing, and sterilization of dental instruments, highlighting any changes in the process due to the COVID-19 pandemic, in both private and public dental clinics in the city of Pelotas, Rio Grande do Sul, with the aim of enhancing the safety and effectiveness of sterilization in dental practice after a global health crisis, and to propose a Standard Operating Procedure (SOP). Methods: data were collected at a single time point through questionnaire responses provided by the professional responsible for the sterilization process at each location. The data were compiled using Microsoft Excel software, and descriptive analysis was conducted. The results were expressed in the form of percentages. Results: in 100% of the locations, the washing and sterilization process took place in the same treatment room. Out of these, transportation was conducted using a hygienizable plastic box in four locations, and six locations had a pre-washing process. All locations used an autoclave for the sterilization process, and 100% performed chemical monitoring of the process, but only four locations conducted biological monitoring. Conclusion: there were few changes in the washing and sterilization processes at the surveyed locations due to the emergence of the COVID-19 pandemic. None of the examined locations had a described SOP for the washing and sterilization process of dental instruments, and there was a low utilization of biological indicators, which are considered the gold standard for biosafety.(AU)

Análisis microbiológico a corto y largo plazo del material usado para esterilizar instrumental odontológico / Short and long-term microbiological analysis of the material for sterilize dental instruments

Introducción: el material para empaquetar el instrumental odontológico, como pueden ser bolsas de tela, papel o plástico, es usado por profesionales de la salud; sin embargo, es necesario esclarecer la efectividad de cada uno y determinar el tiempo que permanece estéril luego del procedimiento. Objetivo: identificar la eficacia de tela, plástico y papel como materiales para esterilizar instrumental a corto y largo plazo. Material y métodos: se realizaron cultivos sólidos y líquidos de instrumental esterilizado en tres materiales y con diferentes tiempos de postesterilización. Se incubaron a 36 oC por 72 horas en condiciones aerobias y anaerobias. Los resultados se analizaron usando una prueba de Kruskal-Wallis, seguida de una prueba de Dunn. Resultados: los resultados mostraron que inmediatamente después del proceso de esterilización, los tres materiales son efectivos (Kruskal-Wallis test, p = 0.2752), 24 horas (p = 0.2492), siete (p = 0.0509) y 14 días (p = 0.0006). Veinticuatro horas posterior a la esterilización la tela no es efectiva, el plástico disminuye su efectividad y el papel sigue siendo efectivo. Conclusión: en nuestros resultados, el papel es la mejor opción para esterilizar instrumental (AU)

Introduction: material such as cloth, paper or plastic bags to wrap dental instruments is used by health professionals, however, it is necessary to clarify the effectiveness of each one and determine if it remains sterile after the procedure. Objective: to determine the effectiveness of cloth, plastic and paper as materials to sterilize dental instruments in the short and long term. Material and methods: we carry out solid and liquid cultures of sterilized instruments in three materials, at different post-sterilization times, incubated at 36 oC for 72 hours under aerobic and anaerobic conditions, and the results were analyzed using a Kruskal-Wallis test, followed by from a Dunn's test. Results: our results showed that immediately after the sterilization process the three materials are effective (Kruskal-Wallis; p = 0.2752), 24 hours (p = 0.2492), 7 (p = 0.0509) and 14 (p = 0.0006) days. Twenty-four hours after the cloth is not effective, plastic decreases its effectiveness and paper remain effective. Conclusion: in our results, paper is the best option to sterilize dental instruments (AU)

Evaluación clínica y microbiológica usando tres técnicas de eliminación de tejido cariado / Avaliação clínica e microbiológica de três técnicas para eliminação do tecido cariado / Root fracture in the permanent maxillary central incisors: a case report of 10 years follow-up

Objetivo: Comparar, la efectividad clínica y microbiológica, entre las técnicas de eliminación tradicional y químico-mecánicas, para el tratamiento de lesiones cavitadas abiertas no penetrantes en dientes primarios en niños de 4 a 8 años, analizándose 57 dientes primarios. Grupo I: técnica tradicional (19 piezas), Grupo II: Brix (18 piezas), Grupo III: Papacarie (20 piezas). Evaluación clínica (necesidad de anestesiar y tiempo de ejecución) los datos fueron asentados en cada historia clínica. Antes y después del procedimiento operatorio, se tomaron muestras de la cavidad con microbrush estéril, transportándolas en tioglicolato para analizar cuantitativamente el total de bacterias presente por mililitro, utilizando cultivos de agar sangre (base Columbia). La información fue tabulada y analizada estadísticamente mediante Análisis de la Variancia, pruebas de Tukey y de Chi Cuadrado, estableciéndose como criterio de significancia p≤0.05. La diferencia significativa en la cantidad de bacterias entre el grupo I (41.22 ± 4.45) y los grupos II y III (65.96 ± 4.33, 83.45 ± 4.57), reveló que el grupo I fue menos efectivo. En los grupos II y III no se requirió la utilización de anestesia, siendo significativa la diferencia en los niños de edad preescolar (4 y 5 años). El tiempo de ejecución para cada técnica manifestó mayor rapidez en el grupo I (2.12 min ± 0.15) p˂0.0001. Las técnicas que utilizan algún agente químico permiten una mayor eliminación de bacterias durante la remoción de tejido cariado, sin recurrir a anestesia, por lo que pueden ser recomendadas como alternativa al tratamiento tradicional especialmente en niños pequeños.

Objetivo. Este estudo pretende comparar a eficácia clínica e microbiológica de três técnicas para a eliminação do tecido cariado, em crianças dos 4 aos 8 anos. Materiais e Método. Cinquenta e sete dentes decíduos foram analisados. Grupo I: técnica tradicional (19 dentes), Grupo II: Brix (18 dentes), Grupo III: Papacarie (20 dentes). Os dados para avaliação clínica (necessidade de anestesia e tempo de execução) foram registrados em cada anamnese. Antes e após o procedimento operatório, foram retiradas amostras da lesão cariosa com microbrush estéril, transportadas em tioglicolato para análise quantitativa do total de bactérias presentes por mililitro, utilizando culturas de ágar sangue (base Columbia). A informaçâo foi tabulada e analisada estatisticamente por meio do Analize da Varianza, testes de Tukey e do Qui-Quadrado, estabelecendo-se p≤0.05 como critério de significância. Resultados. A diferença na cantidade de bactérias entre o grupo I (41.22 ± 4.45), II e III (65.96 ± 4.33, 83.45 ± 4.57), revelou que o grupo I foi menos eficaz. Os grupos II e III não necessitaram do uso de anestesia, sendo a diferença significativa no grupo de pré-escolares (4 e 5 anos). O tempo de execução de cada técnica foi mais rápido no grupo I (2.12 min ± 0.15) p˂0.0001. Conclusão. As técnicas que utilizam algum agente químico permitem uma maior eliminação de bactérias durante a remoção do tecido cariado, sem recorrer à anestesia, podendo ser recomendadas como alternativa ao tratamento tradicional, especialmente em crianças pequenas.

Aim. This study pretends to compare the clinical and microbiological effectiveness of three techniques for the elimination of carious tissue in children aged 4 to 8 years old. Methods. Fifty-seven primary teeth were analyzed. Group I: traditional technique (19 teeth), Group II: Brix (18 teeth), Group III: Papacarie (20 teeth). The data for clinical evaluation (need for anesthesia and running time) were recorded in each case history. Before and after the operative procedure, samples were taken from the carious lesion with sterile micro brush, transported in thioglycollate to quantitatively analyze the total bacteria present per milliliter, using blood agar cultures (Columbia base). Information was tabulated and statistically analyzed using Analysis of Variance, Tukey's and Chi Square tests, establishing p≤0.05 as the criterion of significance. Results. The difference on number of bacteria between group I (41.22 ± 4.45), and groups II and III (65.96 ± 4.33, 83.45 ± 4.57), revealed that group I was less effective. Groups II and III did not require the use of anesthesia, the difference being significant in the group of pre-school children (4 and 5 years old). The execution time for each technique was faster in group I (2.12 min ± 0.15) p˂0.0001. Conclusions. Techniques that use some chemical agents allow a greater elimination of bacteria during the removal of carious tissue, without resorting to anesthesia, can be recommended as an alternative to traditional treatment especially in young children.

Influence of traverse and waveone gold glider glide path files on the amount of apically extruded debris / Influência das limas glide path Traverse e Wave One Gold Glider na quantidade de detritos extruídos apicalmente

Objective: The aim of this study was to evaluate the effect of different glide path files on the amount of apically extruded debris. Material and Methods: Sixty single-canaled mandibular premolars were accessed and randomly divided into three groups (n= 20) according to the file used for glid path creation; group A using Traverse file, group B using WaveOne Gold Glider, group C using stainless steel K file. All teeth were then instrumented using the Reciproc system. The debris extruded apically during instrumentation were collected into pre-weighed Eppendorf tubes which were then stored in an incubator at 70 °C for 5 days. The weight of the dry extruded debris was established by subtracting the pre-instrumentation and post instrumentation weights of the Eppendorf tubes. The data were analyzed using one-way ANOVA test, and post hoc analysis. Results: WaveOne Gold Glider produced the least amount of apical extruded debris (0.41±0.25) followed by the Traverse group (0.59±0.20) then the K-file group (0.64±0.16) with a statistically significant difference (p=0.003). Conclusion: Apical extrusion of debris is inevitable during root canal cleaning and shaping. Creation of glide path using engine-driven files produces less amount of apically extruded debris compared to hand-driven K-files. (AU)

Objetivos: O objetivo deste estudo foi avaliar o efeito de diferentes limas glide path na quantidade de detritos extruídos apicalmente. Metodologia: Sessenta pré-molares inferiores com canal único foram acessados e divididos aleatoriamente em três grupos (n= 20) de acordo com a lima utilizada para criação do glid path; grupo A usando lima Traverse, grupo B usando WaveOne Gold Glider, grupo C usando lima K de aço inoxidável. Todos os dentes foram então instrumentados usando o sistema reciprocante. Os detritos extruídos apicalmente durante a instrumentação foram coletados em tubos Eppendorf pré-pesados que foram então armazenados em uma incubadora a 70°C por 5 dias. O peso dos detritos secos extruídos foi estabelecido subtraindo-se os pesos dos tubos Eppendorf antes e após instrumentação. Os dados foram analisados por meio do teste one-way ANOVA e análise post-hoc. Resultados: WaveOne Gold Glider produziu a menor quantidade de detritos apicais extruídos (0,41±0,25) seguido pelo grupo Traverse (0,59±0,20) e depois pelo grupo K-file (0,64±0,16) com uma diferença estatisticamente significativa (p=0,003). Conclusão: A extrusão apical de detritos é inevitável durante a limpeza e modelagem do canal radicular. A criação do glide path usando limas acionadas por motores produz menos quantidade de detritos extruídos apicalmente em comparação com as limas K manuais. (AU)

Efectividad de tres métodos de desobturación sobre modelos réplica / Effectiveness of three unsealing methods on replica models

El objetivo fue evaluar la eficacia de remoción del material de obturación y el tiempo empleado para la desobturación con tres métodos diferentes, en modelos réplica. Se utilizaron 24 modelos réplica de premolares inferiores instrumentados con sistema Protaper Gold hasta F4, irrigación NaOCl 2,5% y ED-TAC 17%. Obturación termoplastizada sistema Fast Pack Pro. La muestra (n=24) se dividió aleatoriamen-te en tres grupos experimentales (n=8) sometidos a distintos métodos de desobturación. Grupo 1: fresas Gates Glidden II/III y limas Hedstroem. Grupo 2: lima Medium sistema Wave One Gold y punta ultrasóni-ca Ultra X, (Eighteeth). Grupo 3: lima Rotate 35/04 y punta ultrasónica R1 Clearsonic, (Helse). Se midió el tiempo de desobturación. Las piezas se radiogra-fiaron con radiovisiógrafo digital RVG 5200 (Cares-tream), y fueron procesadas con software Image-J. Al analizar cantidad de material de obturación rema-nente, la prueba de Kruskal-Wallis (p<0,05), mostró diferencias estadísticamente significativas entre grupos 2 y 3. Grupo 1 no mostró diferencias signifi-cativas con los otros dos (p>0,05). Al analizar tiempo de desobturación, el test de Kruskal-Wallis no deter-minó diferencias significativas entre grupos 1 y 2 (p>0,05), el grupo 3 tuvo diferencias estadísticamen-te significativas con los grupos 1 y 2 (p<0,05). En con-clusión, ninguno de los sistemas de desobturación evaluados logró eliminar la totalidad del material de obturación. El que combinó limas rotatorias con punta ultrasónica de retratamiento fue el que mos-tró mayor efectividad de remoción y demandó menor tiempo de trabajo (AU)

Objective: to evaluate the effectiveness of obturation material removal and the time that the procedure took, when performing the retreatment with three different methods, in replica models of mandibular premolars. Materials and methods: 24 replica models of lower premolars instrumented with Protaper Gold system up to F4, 2.5% NaOCl irrigation and 17% ED-TAC were used. Thermoplastized sealing with Fast Pack Pro system. The sample (n=24) was randomly divided in three experimental groups (n=8) subjected to different unsealing methods. Group 1: Gates Glid-den burs II and III and Hedstroem files. Group 2: Wave One Gold Medium file system and Ultra X ultra-sonic tip, (Eighteeth). Group 3: Rotate 35/04 file and R1 Clearsonic ultrasonic tip (Helse). Unsealing time was measured. The samples were radiographed with a digital radiovisiograph RVG 5200 (Carestream), and processed with Image-J software. When analyzing the amount of remaining filling material, Kruskal-Wallis test showed statistically significant differences be-tween groups 2 and 3 (p<0,05). Group 1 did not show significant differences with the other two (p>0,05). When analyzing unsealing time, Kruskal-Wallis test determined that there were no significant differ-ences between groups 1 and 2 (p>0,05), but group 3 had statistically significant differences with the other two (p<0.05). None of the unsealing systems evalu-ated managed to eliminate all of the sealing material. The group that combined rotary files with ultrasonic retreatment tip showed the greatest removal effec-tiveness and required less work time (AU)

Pulpectomía mecanizada en molares primarios: caso clínico / Mechanized pulpectomy in primary molars: a clinical case

Las pulpectomías en molares primarios están indica-das en casos de diagnóstico de pulpitis irreversible o necrosis y reabsorción radicular mínima o nula. Son tratamientos laboriosos y extensos, que sólo pueden ser llevados a cabo en pacientes colaboradores. En búsqueda de simplificar esta terapéutica y mejorar su eficacia, se propone la mecanización de la pre-paración de los conductos de molares primarios. Diversos autores aseguran que esta técnica opti-miza el tiempo clínico y mejora la calidad del trata-miento, obteniendo gran aceptación en la literatura actual. Se presenta la secuencia de procedimientos, resolución y controles de dos tratamientos de pul-pectomía con instrumentación mecanizada en mola-res primarios (AU)

Pulpectomies in primary molars are indicated in cases of irreversible pulpitis or necrosis with mini-mal or no root resorption. They are laborious and ex-tensive treatments, which only can be carried out in cooperative patients. In order to simplify this therapy and improve its effectiveness, the mechanization of root canal preparation is proposed. Several authors assume that this technique optimizes preparation time and improves the quality of treatment, obtaining great acceptance in the current literature. We report the sequence of procedures, resolution, and controls of two pulpectomies with mechanized instrumenta-tion in primary molars (AU)

Endodontic file separation and its management among dentists in Punjab, Pakistan: a cross-sectional study

The study aimed to find the incidence and awareness of endodontic instrument separation and its management among dental house officers, postgraduate trainees, demonstrators, consultants, and general dentists. Methods: This online questionnaire-based cross-sectional study was conducted with the approval of the IRB in private and public dental hospitals and dental clinics in Punjab. The authors developed the survey tool, which comprises 24 closed-ended items regarding demographics, the incidence of file separation, and awareness about its management. The data were analyzed using IBM SPSS version 24. The Chi-Square Test was used to compare percentages of categorical variables. Results: Postgraduate trainees experienced the most instrument separations (43.6%), made the most retrieval attempts (49.2%), and experienced the most secondary errors during retrieval (52.1%) (p<0.001). Around four out of ten respondents always informed the patients (39.6%) and department (41.6%) about errors. Manual files (69.8%), stainless steel files (75.8%), and short files (60.4%) were more frequently separated, and the most frequent cause was older fatigue files (57.7%). Manual files were more frequently broken in public dental institutes (p=0.003). Two-thirds of the file separations (72.5%) occurred during cleaning and shaping in the apical third of molars (65.1%), especially in mesiolingual canal (56.4%). Bypass attempt was the most common in symptomatic teeth (47.7%). Conclusions: Preventive approaches such as limiting file reuse and constructing a glide path can reduce the occurrence of file separation. Operators should be familiar with the number of uses of the instrument before fatigue and should be trained through workshops and refresher courses

Tratamiento de Superficie utilizados en Microtornillos de Ortodoncia y su Efecto en la Estabilidad Primaria y Secundaria: Revisión Bibliográfica / Surface treatment used in Orthodontic Miniscrews and their Effect on Primary and Secondary Stability: Narrative Review

Resumen: Los microtornillos de ortodoncia corresponden a dispositivos de anclaje temporal que sirven como coadyuvantes en el tratamiento ortodóncico y cuyo uso se ha ido incrementando en el último tiempo. Las fallas de los microtornillos tienden a ocurrir durante la primera semana de inserción por lo que mejorar la estabilidad es un paso importante para mejorar la confiabilidad del tratamiento. Una posible solución a esto es modificar la superficie del microtornillo. Objetivo: Identificar en la literatura actual los tratamientos de superficie más utilizados que favorezcan la estabilidad primaria y secundaria en el éxito de los microtornillos en ortodoncia. Material y método: Se realizó una búsqueda en Pubmed y EBSCO con los términos en idioma inglés "miniscrew"/"mini implant" AND "surface", "treatment" and "stability". Se incluyeron los estudios realizados in vivo con el objetivo de comparar y/o evaluar el efecto de los tratamientos realizados en la superficie del microtornillo en el éxito o estabilidad de éste, artículos disponibles en inglés y español. Se excluyeron estudios realizados en implantes dentales y/o médicos, in vitro, estudios clínicos sin grupo control. Resultados: 25 publicaciones fueron utilizadas en la revisión, habiendo 11 tipos de tratamiento de superficie estudiados. La generación de ma trices de nanotubos de óxido de titanio, fotofuncionalización mediada por rayos ultravioleta y anodizado de superficie evidenciaron aumento de la estabilidad de los microtornillos. El uso de técnicas convencionales: grabado ácido, arenado-grabado ácido, no es concluyente en cuanto a su efecto en la estabilidad. Conclusión: Hay escasa evidencia sobre los tratamientos de superficie realizados en microtornillos de ortodoncia para la mejora de su estabilidad. Técnicas pioneras como la generación de matrices de nanotubos de óxido de titanio, fotofuncionalización mediada por rayos ultravioleta y anodizado de superficie evidenciaron aumento de la estabilidad de los microtornillos, siendo necesaria la replicación de los estudios en humanos. La utilización de técnicas convencionales tales como grabado ácido y arenado-grabado ácido, no es concluyente en cuanto a su efecto en la estabilidad de los microtornillos.

Abstract: Orthodontic miniscrews are temporary anchoring devices that help as adjuvants in orthodontic treatment and whose use has increased in recent times. Miniscrew failures can happen during the first week of insertion, so improving stability is an important step to enhance treatment reliability. A possible solution to this issue is to modify the miniscrew surface. Objective: To identify in the current literature the most widely used surface treatments that favor the primary and secondary stability and success of orthodontic miniscrews. Material and method: A search was made in Pubmed and EBSCO with the English terms "miniscrew"/"mini implant" AND "surface", "treatment" and "stability". In vivo studies were included with the aim of comparing and/or evaluating the effect of the treatments performed on the miniscrew's surface and their success or stability, articles available in English and Spanish. Studies performed in dental and/or medical implants, in vitro, clinical studies without control group were excluded. Results: 25 publications were used in the review, with 11 types of surface treatment studied. The generation of titanium oxide nanotube matrices, ultraviolet-mediated photofunctionalization and surface anodizing showed an increase in the stability of the miniscrews. The use of conventional techniques: acid etching, sandblasting-acid etching, is inconclusive as to its effect on stability. Conclusion: There is little evidence of surface treatments performed on orthodontic miniscrews to improve their stability. Pioneering techniques such as the generation of titanium oxide nanotube matrices, ultraviolet-mediated photofunctionalization and surface anodizing showed increased stability of the miniscrews, and require their replication on human studies. The use of conventional techniques such as acid etching and acid sandblasting-etching is inconclusive as to its effect on the stability of the miniscrews.

Diagnostic consistency for observing endodontic files in digital radiographs displayed on different electronic devices / 中华口腔医学杂志

Objectives: To evaluate the diagnostic consistency of working lengths by observing endodontic files in root canals and periapical subtle structures in digital intraoral radiographs presented in two smartphones, a tablet and a laptop computer. Methods: A dried human skull embedded in an acrylic compound was used for exposing radiographs of the upper and lower second premolars and first molars with two endodontic files (Kerr files size 10 and 15) positioned to the full length of the roots or 1.5 mm short of apexes. A total of 100 radiographs were taken for each of the file sizes. Five observers were asked to assess all the 200 digital radiographs according to a 5-category scale in smartphone A (HUAWEI P9 Plus), smartphjone B (Apple iPhone 7), tablet (Apple iPad 2018) and laptop computer (Lenovo Thinkpad E480), respectively. The gold standard for receiver operating characteristic curve (ROC) analysis was determined with the endodontic Kerr file size 20. A total of 150 roots with files were radiographed, 75 of which with files reaching the radiographic apexes of the respective roots and 75 of which with files 1.5 mm short of the radiographic apexes for each endodontic file size. Results from ROC analysis was analyzed with one-way ANOVA and independent sample t test. Results: For the Kerr file size 10, the area under the ROC curve for laptop, tablet and two smartphones were 0.891±0.037, 0.869±0.037, 0.870±0.017 and 0.849±0.037, while for the Kerr file size 15 the ROC values were 0.957±0.02, 0.961±0.02, 0.961±0.01 and 0.961±0.02, respectively. There were no significant differences for diagnostic accuracy for observing endodontic file positions among digital radiographs presented in the two smartphones, one tablet and one laptop devices (endodontic file size 10: F=1.39, P=0.281; endodontic file size 15: F=0.05, P=0.985). A significant difference was found in the diagnostic accuracy of endodontic file positions between size 10 and 15 files in different display devices (t=-10.65, P<0.001). Conclusions: There was a high diagnostic consistency in the determination of working length and periapical subtle structures of roots by observing digital radiographs displayed on smartphones, tablet and laptop computer.

Evolution and development: engine-driven endodontic rotary nickel-titanium instruments / 国际口腔科学杂志·英文版

Various engine-driven NiTi endodontic files have been indispensable and efficient tools in cleaning and shaping of root canals for practitioners. In this review, we introduce the relative terms and conceptions of NiTi file, including crystal phase composition, the design of the cutting part, types of separation. This review also analysis the main improvement and evolution of different generations of engine-driven nickel-titanium instruments in the past 20 years in the geometric design, manufacturing surface treatment such as electropolishing, thermal treatment, metallurgy. And the variety of motion modes of NiTi files to improve resistance to torsional failure were also discussed. Continuous advancements by the designers, provide better balance between shaping efficiency and resistance to of NiTi systems. In clinical practice an appropriate system should be selected based on the anatomy of the root canal, instrument characteristics, and operators' experience.

The Evidence-based Periodontal Risk Assessment (PRA) Tool for Nonsurgical Periodontal Therapy in a Comprehensive Periodontal Management by Risk Assessment (PEMBRA)

ABSTRACT@#In the management of periodontitis patients, periodontal risk assessment (PRA) tool is currently being applied during periodontal review (PR). However, an assessment of risk profiles during examination and diagnosis (E&D) may and would effectively assess and diagnose patients’ periodontal conditions, provide personalised treatment planning, and render an enhanced patient care through periodontal management by risk assessment (PEMBRA). From a retrospective study on selected records of 81 patients treated for chronic periodontitis, the PRA profiles of the patients were evaluated during E&D and two to three months after completion of nonsurgical periodontal therapy (NSPT) during PR. The results were analysed using SPSS version 24 for descriptive statistics. On E&D, the patients presented with 25.9% localised and 74.1% generalised chronic periodontitis. Of these, 2.5% of low-risk patients on E&D increased to 21% during PR signifying an improvement after the treatment. However, the medium-risk patients have a slight increase from 32% to 35%, and patients with a high risk of 62% were reduced to 43%. The improvement of the risk profiles for both low and high-risk groups was mostly contributed by the reduction in the plaque score, percentages of bleeding on probing (BOP), and probing pocket depth (PPD) ≥ 5 mm. This evidence-based evaluation of PRA tool during E&D and PR is important for PEMBRA as it encouraged the clinicians to adopt periodontal management through basic periodontal examination, detailed periodontal charting, radiographic interpretation, tooth per tooth prognosis, diagnosis, and targeted NSPT.

Cyclic Fatigue Resistance and Surface Roughness of Rotary NiTi Instruments after Simulated Clinical Use in Curved Root Canals - An Atomic Force Microscopy Study

Abstract Objective: To examine the cyclic fatigue resistance and surface topography of TruNatomy and ProTaper Gold nickel-titanium rotary files and evaluate the presence of alterations to surface topography following instrumentation in simulated curved canals. Material and Methods: Twenty-four nickel-titanium instruments, twelve each of TN and PTG file systems, were evaluated for cyclic fatigue resistance. The rotary files were rotated in a simulated root canal with standardized diameter, angle of curvature, and radius of curvature in a custom-made cyclic fatigue testing device until the instrument fracture occurred. The time to fracture for each instrument was recorded with a stopwatch; in seconds in each group. Fractured instruments were subjected to atomic force microscopy analysis measuring the average roughness and the root mean square values to investigate surface features of endodontic files. Mean values and standard deviation were calculated. Data were analyzed using the Mann-Whitney U test. Results: Time to fracture was marginally higher in PTG instruments than in the TN file systems. PTG files exhibited higher surface roughness when compared with TN files (p<0.05). Conclusion: TN file system had a higher cyclic fatigue resistance than PTG. Cyclic fatigue causing file breakage did affect the surface topography of the files. PTG files showed a higher surface porosity value than the TN files (AU).

Influência do hipoclorito de sódio na resistência à fadiga cíclica em instrumentos rotatórios endodônticos de memória controlada de NiTi: uma avaliação experimental / Influence of sodium hypochlorite on cyclic fatigue resistance in niti controlled memory endodontics rotary instruments: an experimental evaluation

Introdução: É importante saber se o hipoclorito de sódio (NaOCl) influencia a resistência à fadiga cíclica das limas de níquel-titânio (NiTi). Objetivo: Avaliar a influência de NaOCl 2,5% na resistência à fadiga cíclica de dois sistemas de NiTi. Material e método: 40 instrumentos rotatórios - 20 TruNatomy® (TRU, Dentsply Sirona, Maillefer, Ballaigues, Suíça) e 20 Prodesing Logic2® (PDL2, Bassi, Belo Horizonte, Minas Gerais, Brasil) - foram aleatoriamente distribuídos em 4 grupos experimentais (n = 10) imersos em água destilada (H2O) e NaOCl 2,5% em temperatura a 37°C. Foram submetidos a testes de fadiga cíclica mensurando o número de ciclos para fratura (NCF) e análise dessas superfícies pós-teste em microscópio eletrônico por varredura. Para a análise estatística entre os grupos, foi aplicada a análise de variância (ANOVA), complementada com o pós-teste de Tukey. Resultado: Houve diferença estatística em todos os grupos (P<0.05). Os instrumentos PDL2 obtiveram maior resistência à fratura nas condições em H2O e em NaOCl 2,5% comparados aos instrumentos TRU. Na análise de grupos de instrumentos nas soluções de NaOCl e H2O, foi observado que o NaOCl 2,5% diminuiu o NCF. Conclusão: A resistência à fadiga cíclica dos instrumentos TRU e PDL2 diminuiu com NaOCl 2,5%. Os instrumentos PDL2 foram mais resistentes à fratura em relação aos instrumentos TRU.

Introduction: It is important to know whether sodium hypochlorite (NaOCl) influences the cyclic fatigue resistance of nickel-titanium (NiTi) files. Objective: To evaluate the influence of NaOCl 2.5% on the cyclic fatigue resistance of two NiTi systems. Material and method: Forty rotary instruments - 20 TruNatomy® (TRU, Dentsply Sirona, Maillefer, Ballaigues, Switzerland) and 20 Prodesign Logic2® (PDL2, Bassi, Belo Horizonte, Minas Gerais, Brazil) - were distributed randomly across four experimental groups (n=10) and submerged in distilled water (H2O) or 2.5% NaOCl at 37°C according to allocation. Cyclic fatigue testing was then performed, measuring the number of cycles to fracture (NCF), and post-test surfaces were analysed by scanning electron microscopy (SEM). Statistical Analysis: Analysis of variance (ANOVA) was applied for between-group analysis, followed by Tukey's post-hoc test. Result: A significant difference was observed in all groups (P<0.05). PDL2 instruments showed higher fracture resistance under H2O and 2.5% NaOCl conditions compared to TRU. Analysis of all instrument groups showed that exposure to 2.5% NaOCl decreased the NCF compared to H2O. Conclusion: Cyclic fatigue resistance of the TRU and PDL2 instruments was decreased by exposure to 2.5% NaOCl. PDL2 instruments were more resistant to fracture than TRU instruments.

Evaluation of temperature effect on cyclic fatigue resistance of nickel-titanium instruments in a double-curved canal: a comparative study / Avaliação do efeito da temperatura na resistência a fadiga cíclica de instrumento níquel titânio em canal com dupla curvatura: estudo comparativo

Objective: To investigate the effect of room and body temperatures on cyclic fatigue resistance of three endodontic nickel-titanium rotary files: Hyflex EDM (HEDM) (Coltene/Whaledent, Switzerland), WaveOne Gold (WOG) (Dentsply Maillefer, Switzer), and EdgeOne Fire (EOF) (EdgeEndo, Albuquerque, New Mexico, USA) in a double- curved canal. Material and Methods: In this study, Sixty NiTi rotary files were used. These files were divided into three groups (n = 20 for each group). Group A: HEDM (size 25, taper 0.08), group B: WOG (size 25, taper 0.07), and group C: EOF (size 25, taper 0.07). Each group was subdivided into two subgroups (n=10 for each subgroup). One of the subgroup was subjected to cyclic fatigue test at room temperature (20±1°C), while the other subgroup was subjected to cyclic fatigue test at body temperature (37±1°C). These files were tested by using a custom-made artificial canal with a double curvature (coronal curve: 60° curvature with 5 mm radius; apical curve: 70° curvature with 2 mm radius). All instruments were rotated according to the manufacturer instructions until the fracture occurred by using electric endodontic motor (Wave One, Dentsply Maillefer, Ballaigues, Switzerland). The number of cycles to fracture (NCF) and the fractured fragment length (FL) were recorded for each endodontic file. The data were gathered and statistically analyzed using shapiro-wilk test and two-way ANOVA test. The statistical significance was set at 0.05. Results: The NCF of WOG and EOF were significantly lower at body temperature as compared to room temperature (p ≤ 0.05), whereas no difference was observed in NCF of HEDM at body and room temperatures (p>0.05). At 20±1°C, the results showed a non-significant difference between NCF of WOG and EOF (p>0.05), while the NCF of HEDM was significantly lower than the other groups (p ≤ 0.05). At 37±1°C, the results showed a non-significant difference in NCF among the tested endodontic files (p ≤ 0.05). There is non-significant difference in FL of each group at (20±1°C) and (37±1°C) (p>0.05). No statistical difference in FL among the tested files at room and body temperatures (p>0.05). Conclusion: The temperature has a significant effect on cyclic fatigue resistance of EOF and WOG, whereas no effect was observed on cyclic fatigue resistance of HEDM. WOG and EOF had a comparable NCF, while HEDM had a lower NCF than other groups at room temperature. At body temperature, all tested files have a comparable NCF. These results were attributed to the type of the alloy and heat treated that was used to manufacture these endodontic files. The cyclic fatigue test should be done at body temperature (AU)

Objetivo : Investigar o efeito das temperaturas ambiente e corpórea na resistência a fadiga cíclica em três instrumentos endodônticos rotatório de níquel-titânio: Hyflex EDM (HEDM)(coltene/Whaledent, Switzerland), WaveOne Gold (WOG) Dentsply Maillefer, Switzer), e EdgeOne Fire (EOF) (EdgeEndo, Albuquerque, New Mexico, USA) em canais com dupla curvatura. Material e Métodos : Neste estudo foram utilizadas sessenta limas endodônticas rotatórias. Esses grupos foram divididos em três grupos (n=20). Grupo A: HEDM (tamanho 25, conicidade 0.08), grupo B: WOG (tamanho 25, conicidade 0.07), e grupo C: EOF (tamanho 25, conicidade 0.07). Cada grupo foi subdivididos em dois subgrupos (n=10). Um dos subgrupos foi submetido ao teste de fadiga cíclica em temperatura ambiente (20±1°C), enquanto o outro subgrupo foi submetido a ao teste de fadiga cíclica em temperatura corpórea (37±1°C). Essas limas foram testadas em um canal artificial feito sob medida com duas curvaturas (curva coronal: curvatura de 60º e com 5 mm de raio; curva apical: curvatura de 70º com 2mm de raio); Todos os instrumentos foram rotacionados de acordo com a instrução do fabricante até que a fratura ocorresse utilizando um motor endodôntico elétrico (Wave One, Dentsply Maillefer, Ballaigues, Switzerland). O número de ciclos até a fratura (NCF) e a comprimento do fragmento fraturado (FL) foram registrados para cada lima endodôntica. Os dados foram coletados e analisados pelo teste shopiro-wilk e ANOVA two-way. A significância estatística foi 0.05. Resultados: O NCF do WOG e do WOF foi significantemente menor na temperatura corpórea em comparação à temperatura ambiente (p ≤ 0.05), enquanto não foi observada diferença entre NCF em HEDM em temperatura corpórea e temperatura ambiente (p>0.05). Em 20±1°C, os resultados mostraram diferença não significativa entre o NFC com WOG e EOF (p>0.05), enquanto o NCF com HEDM foi significante menor que os demais grupos (p ≤ 0.05). A 37±1°C, os resultados mostraram diferença não significativa em NCF entre as limas endodônticas testadas (p ≤ 0.05). Há diferença não significativa no FL de cada grupo (20±1°C) e (37±1°C) (p>0.05). Não houve diferença estatisticamente diferente no FL entre as limas testadas nas temperaturas ambiente e corporal (p>0,05). Conclusão: A temperatura tem efeito significativo na resistência a fadiga cíclica do EOF e WOG, enquanto não foi observado nenhum efeito na resistência a fadiga cíclica do HEDM. WOG e EOF tiveram um NCF comparável, enquanto HEDM teve um NCF menor do que os outros grupos em temperatura ambiente. À temperatura corporal, todas as limas testas apresentam semelhante NCF. Esses resultados foram atribuídos ao tipo de liga e ao tratamento térmico que foi utilizado na fabricação. O teste de fadiga cíclica deve ser feito à temperatura corporal (AU)

Comparison of the High Cycle Fatigue Behavior of the Orthodontic NiTi Wires: An in Vitro Study

Abstract Objective: To compare the high-cycle fatigue behavior of four commercially available NiTi orthodontic wires. Material and Methods: Twelve NiTi orthodontic wires, round, 0.016-in, three per brand, were selected and divided into four groups: G1 - Heat-activated NiTi, G2 - Superelastic NiTi, G3 - Therma-Ti, and G4 - CopperNiTi. The atomic absorption spectrometry method was used to determine the chemical composition of investigated NiTi wires. We also performed a fatigue test at three-point bending using a universal testing machine for 1000 cycles in a 35 °C water bath. For the first and thousandth cycle, the average plateau load and the plateau length were determined in the unloading area of the force versus displacement diagram. In addition, we calculated the difference between the average plateau load of the first and thousandth cycle (∆F), as well as the difference between the plateau length of both cases (∆L). Results: According to our results, there were no significant differences between the average plateau load of the first and thousandth cycles of each group (p>0.05) and in the plateau length of the first and thousandth cycles of the groups (p>0.05). Conclusion: There were no significant differences between the groups changing the superelasticity property after high-cycle fatigue.