Eficácia e importância da patência foraminal em casos de dentes despolpados e em dentes com vitalidade pulpar / Efficacy and importance of apical foramen patency in procedures involving pulpless teeth and teeth with vital pulps

A ciência endodôntica possui um vasto conhecimento e com esse conhecimento os seus inúmeros questionamentos. Algumas teorias e conceitos mudam constantemente e trazem à tona contradições e divergências clínicas no âmbito biológico e prático. A patência foraminal é uma prática que permite que um instrumento de pequeno calibre ultrapasse o forame apical, com o intuito de limpar passivamente e prevenir o acúmulo de detritos e inibir a proliferação de microorganismos que podem causar infecções pós tratamento endodôntico. Essa prática gera discussão interna entre especialistas da área, mas as vantagens da técnica são inúmeras, principalmente no que diz respeito aos casos de polpa necrosada. Casos como esse não são solucionados com sucesso sem a utilização da patência apical. Por outro lado, existem contradições em relação aos casos em que a polpa está viva. Esse trabalho tem como objetivo analisar as vantagens e desvantagens da patência apical, bem como, se os benefícios excedem os possíveis danos que ela pode trazer(AU)

Endodontic science has vast knowledge and with this knowledge its countless questions. Some theories and concepts are constantly changing and bring to light clinical contradictions and divergences in the biological and practical scope. Foraminal patency is a practice that allows a small-caliber instrument to go beyond the apical foramen, in order to passively clean and prevent the accumulation of debris in the region and inhibit the proliferation of microorganisms that can cause infections after endodontic treatment. This practice generates internal discussion among specialists in the field, but the advantages of the technique are numerous, especially with regard to cases of necrotic pulp. Cases like this are not successfully resolved without the use of apical patency. On the other hand, there are contradictions regarding the cases where the pulp is alive. This work aims to analyze the advantages and disadvantages of apical patency, as well as whether the benefits exceed the harm it can bring(AU)

Evaluación radiográfica de 5000 tratamientos endodónticos realizados en premolares y molares mandibulares y maxilares en una población en Argentina / Radiographic evaluation of 5000 endodontic treatments performed on mandibular and maxillary premolars and molars in a population in Argentina

Objetivo: Evaluar radiográficamente tratamientos en- dodónticos del sector posterior de la cavidad bucal y com- parar la frecuencia de aceptabilidad en cada pieza dentaria involucrada. Materiales y métodos: Se evaluaron 5000 radiogra- fías de archivo de tratamientos endodónticos realizados apro- ximadamente entre 2005 y 2019 en premolares y molares mandibulares y maxilares en Argentina. Se consideraron tratamientos correctos e incorrectos de acuerdo con: 1) con- formación de la preparación quirúrgica; 2) límite apical de la obturación; 3) homogeneidad de la obturación. Se obtuvo la fre- cuencia absoluta y relativa de correctos e incorrectos. El aná- lisis entre frecuencias y pieza dentaria se realizó con la prueba de chi cuadrado y el cálculo del coeficiente V de Cramer. Para la comparación entre grupos de piezas dentarias se utilizó la partición del valor de chi cuadrado obtenido en los corres- pondientes grados de libertad. Nivel de significación P <0.05. Resultados: La partición del valor de chi cuadrado no mostró diferencias significativas entre primeros y segundos premolares mandibulares. Las otras comparaciones exhibie- ron diferencias significativas. Conclusiones: Un alto porcentaje de los tratamientos endodónticos de la población estudiada tiene por lo menos una condición que permite categorizarlos como incorrectos según el criterio establecido en este trabajo. Este porcentaje es más preponderante en anatomías complejas (AU)

Aim: To evaluate radiographically endodontic treat- ments performed in the posterior area of the oral cavity and compare the frequency of acceptability in each tooth involved. Materials and methods: 5,000 archival radiographs of endodontic treatments performed between 2005 and 2019 on mandibular and maxillary premolars and molars in Argentina were evaluated. The percentages of correct and incorrect treatments were considered according to 1) shaping of the preparation; 2) apical limit of the obturation; 3) homogeneity of the obturation. The absolute and relative frequencies of correct and incorrect treatments were calcu- lated. The association between these frequencies and tooth type was analyzed using the chi-square test and Cramer's V coefficient. For the comparison between groups of teeth, the partition of the chi-square value obtained in the corre- sponding degrees of freedom was used. Level of significance was P <0.05. Results: The partition of the chi-square value did not show a significant difference between the first and second lower premolars. The differences were significant in the other comparisons. Conclusions: A high percentage of the endodontic treat- ments in the study population have at least one condition war- ranting their classification as incorrect according to the crite- ria established in this study. This percentage is more prevalent in complex anatomies (AU)

Influence of different reciprocating systems on the apical extrusion of debris in flat-oval canals

Aim: To evaluate the apical extrusion of debris in flat-oval canals, using three reciprocating systems at two different working lengths (WL), 0 mm and 1 mm from the apical foramen. Methods: Ninety mandibular incisors were randomly divided into three groups based on the systems: WaveOne Gold #25.07 (WOG), ProDesign R #25.06 (PDR), and X1 Blue #25.06 (X1B). Extruded debris were collected and dried in pre-weighed Eppendorf tubes. Three consecutive weighings were performed for each tube, and the mean was calculated. If the assumptions of normality and homogeneity of variance were not met, the Kruskal-Wallis test was used to analyze the amount of extruded debris between groups with the same WL, and the Mann-Whitney U test was used for comparison within groups for each WL. Results: All groups had extruded debris, with higher median values occurring at 1 mm. No significant difference regarding the amount of debris extrusion was observed at 0 mm (p>0.05) and 1 mm (p>0.05) between groups. However, within the groups, at different WL, there was greater extrusion at 1 mm (p<0.05), with PDR differing significantly from the other systems (p<0.05). Conclusion: The extrusion of debris occurred regardless of the group, with higher values at 1 mm. However, using PDR at 1 mm from the apical foramen showed the highest values of extrusion

Introduction of nickel titanium rotary instruments to undergraduate students: afour-yearclinical experience / Introdução de instrumentos rotários de níquel titânio para alunos de graduação: quatro anos de experiência clínica

Many studies address the quality of root canal treatments, but few refer to endodontics usingrotatory techniques performed by noviceoperators. This study evaluatedthe performance of undergraduates in their first contact with rotary root canal instrumentation concerningthe findings of the final periapical radiograph, and thepostendodontic treatment pain.A longitudinal observational studywas performed on periapical radiographs of 491teethfrom 450 patientssubmitted toroot canal treatmentby undergraduate students from 2015 to 2018. The analysis of the length of root canal filling followed the criteria: (i) acceptable, ifperiapical radiograph presentsroot filling ending 0 -1 mm short of radiographic apex; (ii) over, if periapical radiograph presentsroot filling ending beyond the radiographic apex; and (iii) under, ifperiapical radiograph presentsroot filling ending > 1 mm short of radiographic apex. Evaluation of postendodontic treatment painwas categorized into either absence or presenceof pain. Adequate length root canal filling was observed in 65.9% of the cases (324 teeth). Periapical lesions presenceand dimensions did not interfere to the obturation quality.Statistical relation was found between the pulp condition and postendodontic treatment pain. Thepresence of pain was observed in 4.7% of the vital teeth and 0.3% of non-vital teeth. The presence of periapical lesion did not influence postoperative pain.AdequatelengthrootcanalfillingwasobservedinmostcasesandNitTi rotary instrumentation hadapplicability in undergraduate programs, even with novice operators. Besides that, pulp condition had an effect on post endodontic pain (AU).

Muitos estudos abordam a qualidade dos tratamentos de canal radicular, mas poucos se referem à endodontia por meio de técnicas rotatórias realizada por operadores novatos. Este estudo avaliou o desempenho de graduandos no primeiro contato com a instrumentação endodôntica em relação aos achados da radiografia periapical final e à dor pós-tratamento endodôntico. Um estudo observacional longitudinal foi realizado em radiografias periapicais de 491 dentes de 450pacientes submetidos a tratamento endodôntico por estudantes de graduação no período de 2015 a 2018. A análise do comprimento da obturação de canais radiculares obedeceu aos critérios: (i) aceitável, se a radiografia periapical apresentasse término de obturação 0 -1 mm aquém do ápice radiográfico; (ii) acima, se a radiografia periapical apresentasse obturação que termina além do ápice radiográfico; e (iii) abaixo, se a radiografia periapicalapresentasse obturação, terminando > 1 mm aquém do ápice radiográfico. A avaliação da dor pós-operatória foi categorizada em ausência ou presença de dor. A obturação de canais radiculares de comprimento adequado foi observada em 65,9% dos casos (324 dentes). A presença e as dimensões das lesões periapicais não interferiram na qualidade da obturação. Foi encontrada relação estatística entre a condição pulpar e a dor pós-tratamento endodôntico. Presença de dor foi observada em 4,7% dos dentes vitais e 0,3% dos não vitais. A presença de lesão periapical não influenciou na dor pós-operatória. O comprimento de trabalho adequado foi observado na maioria dos casos e a instrumentação rotatória NitTi teve aplicabilidade em programas de graduação, mesmo com operadores iniciantes. Além disso, a condição pulpar afetou a dor pós-operatória (AU).

Fracture resistance of simulated immature teeth reinforced with different mineral aggregate-based materials

Abstract This study assessed the fracture resistance of simulated immature teeth reinforced with calcium aluminate cement (CAC) or mineral trioxide aggregate (MTA) containing calcium carbonate nanoparticles (nano-CaCO3). The microstructural arrangement of the cements and their chemical constitution were also evaluated. Forty-eight canines simulating immature teeth were distributed into 6 groups (n=8): Negative control - no apical plug or root canal filling; CAC - apical plug with CAC; CAC/nano-CaCO3 - apical plug with CAC+5% nano-CaCO3; MTA - apical plug with MTA; MTA/nano-CaCO3 - apical plug with MTA+5% nano-CaCO3; and Positive control - root canal filling with MTA. The fracture resistance was evaluated in a universal testing machine. Samples of the cements were analyzed under Scanning Electron Microscope (SEM) to determine their microstructural arrangement. Chemical analysis of the cements was performed by Energy Dispersive X-ray Spectroscopy (EDS). The fracture resistance of CAC/nano-CaCO3 was significantly higher than the negative control (p<0.05). There was no significant difference among the other groups (p>0.05). Both cements had a more regular microstructure with the addition of nano-CaCO3. MTA samples had more calcium available in soluble forms than CAC. The addition of nano-CaCO3 to CAC increased the fracture resistance of teeth in comparison with the non-reinforced teeth. The microstructure of both cements containing nano-CaCO3 was similar, with a more homogeneous distribution of lamellar- and prismatic-shaped crystals. MTA had more calcium available in soluble forms than CAC.

Resumo Este estudo avaliou a resistência à fratura de dentes imaturos simulados reforçados com cimento de aluminato de cálcio (CAC) ou trióxido agregado mineral (MTA) contendo nanopartículas de carbonato de cálcio (nano-CaCO3). O arranjo microestrutural dos cimentos e sua constituição química também foram avaliados. Quarenta e oito caninos simulando dentes imaturos foram distribuídos em 6 grupos (n=8): Controle negativo - sem plug apical ou obturação do canal radicular; CAC - plug apical com CAC; CAC/nano-CaCO3 - plug apical com CAC + 5% nano-CaCO3; MTA - plug apical com MTA; MTA/nano-CaCO3 - plug apical com MTA + 5% nano-CaCO3; e Controle positivo - obturação dos canais radiculares com MTA. A resistência à fratura foi avaliada em máquina universal de ensaios. Amostras dos cimentos foram analisadas em Microscópio Eletrônico de Varredura (MEV) para determinar seu arranjo microestrutural. A análise química dos cimentos foi realizada por Espectroscopia de Energia Dispersiva de Raio-X (EDS). A resistência à fratura de CAC/nano-CaCO3 foi significativamente maior do que o controle negativo (p<0,05). Não houve diferença significativa entre os outros grupos (p>0,05). Ambos os cimentos apresentaram microestrutura mais regular com a adição de nano-CaCO3. As amostras de MTA apresentaram mais cálcio disponível em formas solúveis do que CAC. A adição de nano-CaCO3 ao CAC aumentou a resistência à fratura dos dentes em comparação aos dentes não reforçados. A microestrutura de ambos os cimentos contendo nano-CaCO3 foi semelhante, com uma distribuição mais homogênea de cristais de formato lamelar e prismático. MTA apresentou mais cálcio disponível nas formas solúveis do que CAC.

Comparación de la precisión de dos localizadores electrónicos apicales en piezas dentarias con perforaciones simuladas / Comparison of the precision of two electronic apical locators in teeth with simulated perforations

Objetivo: El propósito de este estudio fue comparar la precisión de los localizadores electrónicos apicales Propex Pixi y Raypex 6 en la determinación de la longitud de trabajo de piezas dentarias con perforaciones simuladas a diferentes niveles del conducto radicular. Materiales y Métodos: Se utilizaron 36 premolares inferiores unirradiculares con un conducto, divididos aleatoriamente en tres grupos de 12 piezas dentarias cada uno. En el primer grupo, se realizaron dos perforaciones simuladas que fueron a nivel medio y a nivel apical; en el segundo grupo, se realizó una perforación simulada a nivel cervical, y en el tercer grupo, se realizó una perforación simulada a nivel apical. Se emplearon dos localizadores electrónicos apicales Propex Pixi y Raypex 6. La longitud real del conducto fue medida con un calibrador Vernier digital. Se aplicó estadística descriptiva y estadística inferencial con la prueba de Friedman a un nivel de confianza del 95%. Resultados: Al comparar la precisión de las longitudes obtenidas por los localizadores electrónicos apicales Propex Pixi y Raypex 6 en premolares inferiores con perforaciones simuladas a nivel medio y apical, premolares inferiores con perforación simulada a nivel cervical y premolares inferiores con perforación simulada a nivel apical, se encontraron diferencias estadísticamente significativas en la longitud real del conducto, p < 0,001, p = 0,008 y p = 0,006, respectivamente. Conclusiones: El localizador electrónico apical Propex Pixi (Dentsply Maillefer, Alemania) presentó mayor precisión en la determinación de la longitud real del conducto en piezas dentarias con perforaciones simuladas a diferentes niveles del conducto radicular. (AU)

Objective: The purpose of the study was to compare the precision of the Propex Pixi and Raypex 6 electronic apical locators in determining the working length of teeth with simulated perforations at different levels of the root canal. Materials and Methods: 36 uniradicular lower premolars were used with a canal randomly divided into three groups of 12 teeth each. In the first group two simulated perforations were made at the middle and apical level. In the second group a simulated cervical perforation was made, and in the third group a simulated perforation was performed at the apical level. Two electronic apical locators Propex Pixi and Raypex 6 were used, and the real length of the canal was measured with a digital Vernier caliper. Descriptive and inferential statistics were applied with the Friedman test at a confidence level of 95%. Results: When comparing the precision of the lengths obtained by the Propex Pixi and Raypex 6 apical electronic locators, statistically significant differences were found in the real length of the canal (p= 0.006) between simulated perforation of lower premolars at the cervical (p<0.001) and the apical level (p=0.008), Conclusion: The Propex Pixi apical electronic locator (Dentsply Maillefer - Germany) presented greater precision in the determination of the real canal length in teeth with simulated perforations at different levels of the root canal. (AU)

Análise comparativa da precisão de medição dos localizadores apicais eletrônicos Romiapex a15® e Root zx mini®: um estudo in vitro / Comparative analysis of the measuring accuracy of the electronic apex locators Romiapex a15® and Root zx mini®: an in vitro study

Este estudo analisou a precisão de medição dos aparelhos ROMIAPEX A 15® e ROOT ZX MINI®, in vitro, comparativamente pelo método radiográfico e eletrônico no que diz respeito à precisão e confiabilidade na determinação do Comprimento Real de Trabalho (CRT) e Comprimento Real do Dente (CRD). Vinte dentes humanos (incisivos superiores e pré-molares superiores/inferiores) foram avalia das e seus CRD's e CRT's aferidos de forma direta por meio de lima tipo k nº 10 ou 15 (Dentsply Sirona, Ballaigues, Suíça), pelo método radiográfico e método eletrônico. Não foram verificadas diferenças significativas entre as medidas para CRD (p=0,003) e CRT (p=0,042) entre os métodos direto, radio gráfico e eletrônico. Ambos os métodos ficaram próximos da medida real, quando por vezes também definiram a mesma medida real. Os CRD's obtidos pelos métodos radiográfico e eletrônico foram sub metidos ao Teste t de Student (p<0,024) apontando relação estatística significativa para a verificação da odontometria, sugerindo que ambos os métodos são eficazes na determinação do comprimento real do dente quanto de trabalho. O método eletrônico apresentou eficácia satisfatória estatistica mente nos casos comparativamente aos outros métodos também avaliados. Os dados sugerem que os localizadores citados podem auxiliar as tomadas de decisões para determinação do CRD e CRT

This study analyzed the measurement accuracy of the ROMIAPEX A15® and ROOT ZX MINI® locators, in vitro, comparatively by the radiographic and electronic methods with regard to the precision and reliability in the determination of the Real Working Length (RWL) and Real Tooth Length (RTL). Twenty human teeth (upper incisors and upper/lower premolars) were evaluated it had the RTL and RWL measured through rasp k No 10/15 (Dentsply Sirona, Ballaigues, Switzerland) by radiographic and electronic methods. There were no significant differences between the measures for RTL (p = 0,003) and RWL (p = 0,042) for the methods. It means that both methods were very close to the real measure, when sometimes they also defined the same real measure. The RTL obtained by methods radiographic and electronic, were submitted to Student's t test (p <0,024), showed statistical significance in relation to the methods used for verification of odontometry, which means that both methods are effective to determine an actual length of the element and the length of actual work. The electronic method showed statistically satisfactory effectiveness in the cases compared to the other methods.The data suggest that these locators can assist decision making to determine RTL and RWL ... (AU)

Instrumentação foraminal: repercussões locais e sistêmicas / Foraminal enlargement: Local and systemic repercussions

Introdução: A infecção endodôntica pode alcançar a saída foraminal e, inclusive, ir além dela. Logo, a determinação da constrição apical como o limite ideal para instrumentação e obturação tem sido questionada. A instrumentação foraminal intencional é realizada com o intuito de diminuir o contingente microbiano a níveis mais favoráveis ao reparo. Entretanto, repercussões locais e sistêmicas estão associadas à sua execução. Objetivo: Realizar uma revisão crítica da literatura sobre repercussões locais e sistêmicas relativas à instrumentação foraminal intencional. Métodos: Em março de 2018, uma busca eletrônica realizada na base de dados PUBMED utilizando os termos "foraminal enlargement" OR "foraminal widening" OR "apical limit" AND "endodontics" identificou 74 artigos científicos. Esses artigos, a análise de suas referências bibliográficas e a utilização de mais 5 artigos base resultaram nos 111 estudos consultados para a realização dessa pesquisa. Resultados: A ampliação foraminal intencional nem sempre pode ser praticada em virtude de razões anatômicas e morfológicas. Quanto maior a ampliação do forame apical, maior a possibilidade de extravasamento de substâncias e/ou materiais utilizados para a realização do tratamento endodôntico. A instrumentação foraminal intencional parece ser contraindicada em pacientes que fazem ou fizeram uso de bisfosfonatos recentemente, com distúrbios de coagulação e/ou sob uso crônico de anticoagulantes e com alto risco de bacteremia. Conclusões: Os impactos da instrumentação foraminal intencional sobre o sucesso do tratamento endodôntico devem ser investigados. Contudo, os delineamentos metodológicos dos estudos clínicos devem ser cuidadosos, principalmente no tocante às condições sistêmicas dos pacientes que farão parte do universo amostral (AU).

Introduction: endodontic infection can reach and even go beyond the apical foramen. Therefore, determining apical constriction as the ideal limit for instrumentation and obturation has been questioned. Intentional foraminal enlargement is performed for the purpose of reducing the microbial contingent to levels more favorable to repair. However, local and systemic repercussions have been associated with this approach. Objectives: to critically review the literature on local and systemic repercussions relative to intentional foraminal enlargement. Methods: in March 2018, an electronic search performed on the PUBMED database using the terms "foraminal enlargement" OR "foraminal widening" OR "apical limit" AND "endodontics" identified 74 scientific articles. These articles, analysis of their references and use of another 5 base articles resulted in the 115 studies used for performing this research. Results: intentional foraminal enlargement cannot always be performed due to the anatomical and morphological conditions. The greater the apical foramen enlargement, the greater the possibility of extrusion of substances and/or materials used to perform endodontic treatment. Intentional foraminal enlargement seems to be contraindicated in patients who are taking or have recently used bisphosphonates, those with coagulation disorders and/ or under chronic use of anticoagulants and at high risk for bacteremia. Conclusions: the impacts of intentional foraminal enlargement on the success of endodontic treatment should be investigated. However, the methodological procedures of clinical studies should be carefully designed, especially taking into consideration the systemic conditions of patients who will be part of the sample (AU).

Can kinematics, file diameter, and PUI influence the intracanal decontamination and apical bacterial extrusion?

Abstract: The present study investigated the intracanal decontamination and apical extrusion of bacteria and debris from root canals instrumented with rotary and reciprocating systems (ProDesign Logic or ProDesign R), with different file diameters and using conventional syringe irrigation (CSI) or passive ultrasonic irrigation (PUI). Eighty extracted mandibular premolars were contaminated with Enterococcus faecalis and randomly assigned to eight experimental groups according to the root canal instrumentation and irrigation technique employed (n = 10): G1: Prodesign Logic 25.06; G2: Prodesign R 25.06; G3 and G4 were instrumented with the same single-file systems, respectively, using 35.05 diameters and CSI. G5, G6, G7, and G8 were instrumented like the previous groups, but with PUI. Apically extruded debris during instrumentation was collected into pre-weighed microtubes. The weight of the empty microtube was subtracted from the final weight to establish the amount of extruded debris. Bacteria from root canals and extruded debris were collected for a microbiological evaluation of colony forming units (CFU/mL). For statistical analyses, the Mann-Whitney and Kruskal-Wallis followed by the Dunn's tests were used (α = 0.05). All instruments caused extrusion of debris. For irrigation techniques, PUI promoted greater debris and bacterial extrusion (p < 0.05). The CFU/mL count indicated that the instrumentation of the experimental groups were equally effective in the decontamination of the root canal (p > 0.05). The systems tested (regarding file diameter and kinematics) were associated with similar amounts of apically extruded debris and root canal decontamination. PUI was associated with greater debris and bacterial extrusion.

Evaluación de la distancia entre los ápices de los primeros premolares superiores y el piso del seno maxilar / An evaluation of the distance between the apices of the maxillary first premolars and the maxillary sinus floor

Objetivo: Evaluar distancia cortical/piso de seno maxilar y ápices de primeros premolares superiores, su asociación con sexo y grupo etario. Se midieron 100 premolares superiores, registrándose la distancia ápices/cortical piso del seno, frecuencia de intrusión apical en seno, relación con sexo y grupo etario. Se utilizó prueba de rangos con signos Wilcoxon y prueba Shapiro-Wilk, con modificaciones. Se estimaró método de Wilson. Se utilizó prueba Chi-cuadrado. Se encontró diferencia significativa (Wilcoxon: p<0,05) en distancia máxima a cortical y no la hubo en distancias mínimas a cortical (Wilcoxon: p=0,41). Hubo distribución heterogénea según clasificación de Kwak (Chi-cuadrado=203,8; gl=4; p<0,05): tipo I más representado (77% IC95; 68% a 84%), tipo V menos frecuente (4%; IC95: 2% a 10%). Hubo asociación signficativa entre tipología y sexo (Chi-cuadrado012,48; gl=4; p<0,05). Ambos sexos tipo I más representado, mujeres tipo II menos representado (3%). Se encontró asociación significativa entre tipología y grupo etario (Chi-cuadrado=42,47; gl=20; p<0,05): todos los grupos, tipo I más representado (AU)

Accuracy of Root ZXII, E-PEX and FIND apex locators in teeth with vital pulp: an in vivo study

Abstract: This research evaluated, in vivo, the accuracy of three electronic apex locators - EALs (Root ZXII, E-PEX and FIND) in teeth with vital pulp submitted to biopulpectomy, preserving the periodontal stump. For this study, 90 single-rooted teeth with extraction indication were selected. After positive pulpal cold sensitivity test, pulp chamber access was performed. The cervical and middle thirds of root canals were instrumented with Reciproc R25, and the K#15 file was used as a standard instrument to determine working length, forming 2 groups: Constriction (insertion of the instrument until the apical constriction limit) and Foramen (insertion of the instrument until the foramen and then repositioning at constriction, without removing the file from the canal). The hand file was stabilized with a light-cured flow resin. After extraction, the samples were analyzed through microCT SkyScan 1272, with CTAN software, which evaluated the proximity between the tip of the file to the apical constriction, providing data for comparative analysis using Kruskal-Wallis and Dunn tests (p<0.05). There was a statistically significant difference in the abilities of the EALs to detect the apical constriction after reaching the foramen with Root ZX II showing higher accuracy (89%). However, there was no difference in the accuracy of the three EALs in detecting the apical constriction without reaching the foramen. Based on the present results, we conclude that EALs may show accurate measures in detecting apical constriction and foramen, even without damaging the periodontal stump in biopulpectomy.

Tratamiento de lesiones apicoperirradiculares con un biomaterial de tercera generación (Licon-D) / Treatment of apicoperiradicular lesions with a third-generation biomaterial (Licon-D)

Biomaterial de tercera generación con una tasa de degradabilidad en la zona perirradicular y del foramen apical, con una velocidad similar a la que emplea el organismo para formar tejido calcificado y sellar biológicamente el extremo apical del diente. Mediante el recurso tecnológico de la microencapsulación se produce la liberación lenta y controlada de Ca2+ retenido en la superficie y en el interior de las microesferas de alginato de calcio, sin que se modifique de manera significativa las propiedades reológicas básicas del biomaterial de obturación de conductos, tales como la compresibilidad, plasticidad, extensibilidad, fluidez, viscosidad cinemática, viscosidad de compresión y endurecimiento por trabajo (AU)

Third-generation biomaterial with a degradability rate in the periradicular area and the apical foramen, with a speed similar to that used by the body to form calcified tissue and biologically seal the apical end of the tooth. Through the technological resource of microencapsulation, the slow and controlled release of Ca2+ retained on the surface and inside the calcium alginate microspheres is produced, without significantly modifying the basic rheological properties of the duct sealing biomaterial, such as compressibility, plasticity, extensibility, flowability, kinematic viscosity, compression viscosity, and work hardening (AU)

Influence of different coronal preflaring protocols on electronic foramen locators precision

Abstract: The aim of this study was to evaluate the influence of different coronal preflaring protocols (absent, conservative and conventional) on the accuracy of Root ZX II, Raypex 6, and RomiApex A-15 electronic foramen locators (EFLs). Twenty mandibular molars with Vertucci's type IV mesial roots were subjected to endodontic exploration and foraminal patency confirmation. Under 16x magnification, its real lengths (RL) were measured and registered (RL1). The canals were then irrigated with 2.5% sodium hypochlorite and electronically measured (EM1) employing the alginate model; all measurements were performed in triplicate by a blind operator using adjusted endodontic hand-files introduced until the apex foramen. Coronal preflaring procedures were sequentially performed with #25/.06 (conservative) and #25/.12 (conventional) instruments; new RLs extents were performed after each coronal preparation protocol (RL2/RL3), as same as electronic measurements (EM2/EM3). The devices error (mm) was evaluated considering the difference between RLs and EMs at each preparation stage; their precision was stablished adopting ±0.5 mm as tolerance margin. The EFLs error significantly reduced after conventional coronal preflaring protocol (p<0.05), which not occur after the conservative one. The best precisions values were noted after conventional preparation as 90% (Root ZX II), 97.5% (Raypex 6), and 92.5% (RomiApex A-15). No significant differences were found in EFLs comparisons, regardless of the coronal protocol tested (p>0.05). Under the conditions tested it can be concluded that the EFLs evaluated were precise. Moreover, the preflaring protocols influences its accuracy's, where the less conservative one produced the best results.

Resumo O objetivo deste estudo foi avaliar a influência de diferentes protocolos de pré-alargamento cervical (ausente, conservador e convencional) na precisão dos localizadores eletrônicos foraminais (LEFs) Root ZX II, Raypex 6 e RomiApex A-15. Vinte molares inferiores com raízes mesiais do tipo IV de Vertucci foram submetidos à exploração endodôntica e confirmação da patência foraminal. Sob ampliação de 16x, seus comprimentos reais (CR) foram medidos e registrados (CR1). Os canais foram então irrigados com hipoclorito de sódio a 2,5% e medidos eletronicamente (ME1) utilizando o modelo em alginato; todas as medidas foram realizadas em triplicata por um operador cego, utilizando limas endodônticas ajustadas introduzidas até o forame apical. Os procedimentos de pré-alargamento cervical foram realizados sequencialmente com os instrumentos #25/.06 (conservador) e #25/.12 (convencional); novas determinações de CRs foram realizadas após cada protocolo de preparação cervical (CR2/CR3), da mesma forma que as medidas eletrônicas (ME2/ME3). O erro dos dispositivos (mm) foi avaliado considerando a diferença entre CRs e MEs em cada estágio de preparação; sua precisão foi estabelecida adotando ± 0,5 mm como margem de tolerância. O erro dos LEFs reduziu significativamente após o protocolo convencional de alargamento cervical (p<0,05), o que não ocorreu após o conservador. Os melhores valores de precisão foram observados após a preparação convencional como 90% (Root ZX II), 97,5% (Raypex 6) e 92,5% (RomiApex A-15). Não foram encontradas diferenças significantes nas comparações entre os LEFs, independentemente do protocolo cervical testado (p>0,05). Sob as condições testadas, pode-se concluir que os LEFs avaliados foram precisos. Além disso, os protocolos de alargamento influenciam sua precisão, onde o menos conservador produziu os melhores resultados.

Micro-computed tomographic analysis of apical foramen enlargement of mature teeth: a cadaveric study / Análisis mediante micro-CT del ensanchamiento del foramen apical de dientes maduros: un estudio cadavérico

Revitalization procedures have been extensively studied during the last decade and offers several advantages over root canal treatment, such as the recovery of the natural immune system. Mature teeth have a small apical foramen diameter (AFD), which could impair the ingrowth of tissue into the root canal. We analysed three methods for apical foramen enlargement by instrumentation in in situ human teeth and evaluated the damage over hard tissues produced by the techniques. Tooth length (TL), defined as the length from the most coronal part of the crown to the point at which the file abandons the root canal, was calculated. Forty-four in situ teeth were randomized: Group I: instrumentation 0.5 mm coronal to TL; Group II: at TL level; Group III: 0.5 mm beyond TL. Teeth were instrumented up to K-file #80. The mandibles were scanned in a micro-CT device before and after treatment. Group I: Only 20 % of teeth presented an enlarged AFD, with augmentation of 0.09 mm. No damage to hard tissues was observed. Group II: 71.4 % of the teeth presented an enlarged AFD with augmentation of 0.42 mm. 35.7 % presented damage to periapical tissues. Group III: 86.7 % presented an enlarged AFD with augmentation of 0.43 mm. 46.7 % presented damage to periapical tissues. All groups presented similar prevalence of teeth with dentine thickness less than 1mm. All mandibular incisors presented areas of thickness less than 1mm. Instrumentation 0.5 mm beyond TL is the most effective technique.

La revitalización de dientes necróticos ha sido ampliamente estudiada durante la última década y ofrece varias ventajas sobre la endodoncia convencional, tal como la recuperación del sistema inmunitario natural del diente. Los dientes maduros tienen un diámetro de foramen apical (FA) pequeño, lo que podría afectar el crecimiento de tejido en el conducto. Se evaluaron tres métodos para la ampliación del foramen apical en dientes humanos in situ y se evaluó el daño sobre los tejidos duros producidos por las técnicas. Mediante radiografía periapical se calculó la longitud del diente (TL), definida como la longitud desde la parte más coronal de la corona hasta el punto en que la lima abandonó el conducto radicular. En el estudio fueron aleatorizados 44 dientes in situ: Grupo I: instrumentación 0,5 mm coronal a TL; Grupo II: a nivel TL; Grupo III: 0,5 mm más allá de TL. Los dientes fueron instrumentados hasta la lima K #80. Las mandíbulas se escanearon en un dispositivo de microCT antes y después del tratamiento. Grupo I: solo el 20 % de los dientes presentaron un diámetro de FA ensanchado, con un aumento de 0,09 mm. No se observó daño a los tejidos duros. Grupo II: el 71,4 % de los dientes presentaban un FA ensanchado con un aumento de 0,42 mm. El 35,7 % presentó daño a los tejidos periapicales. Grupo III: el 86,7 % presentó un FA ensanchado con un aumento de 0,43 mm. El 46,7 % presentó daño a los tejidos periapicales. Todos los grupos presentaron una prevalencia similar de dientes con un espesor de dentina inferior a 1mm. Todos los incisivos mandibulares presentaban áreas de grosor inferior a 1mm. La instrumentación 0,5 mm más allá de TL es la técnica más efectiva, aunque se debe tener especial consideración en aspectos como el debilitamiento de la estructura dentaria.

Terapia regenerativa en un incisivo central superior permanente inmaduro: caso clínico / Regenerative therapy in an immature permanent upper central incisor: a clinical case

Objetivo: Presentar la terapia regenerativa como una al- ternativa para la resolución de un caso de traumatismo denta- rio en un diente permanente incompletamente desarrollado. Caso clínico: Se realizó el tratamiento de un incisivo central superior con mortificación pulpar y periodontitis api- cal aguda subsecuente a trauma dental en un paciente de 8 años de edad. Se aplicó el protocolo de regeneración pulpar recomendado por la Asociación Americana de Endodoncia. Se estimuló la formación de un coágulo en el interior del con- ducto a partir de los tejidos periapicales, previa desinfección con la pasta triple antibiótica, y finalmente se colocó mineral trióxido agregado coronal a este. Se obtuvo así una matriz es- teril que permitió el crecimiento de nuevo tejido y se realiza- ron controles periódicos durante 4 años. Se constató silencio clínico. Radiográficamente, se observó la formación de tejido sobre las paredes del conducto y el cierre apical. Conclusión: La terapia regenerativa como alternativa de tratamiento, en este caso, permitió la disminución de la luz del conducto por el depósito de tejidos calcificados y el cierre del foramen apical, mejorando el pronóstico de la pieza dentaria (AU)

Aim: To present pulp regeneration therapy as an alter- native to resolve dental trauma in immature permanent teeth. Clinical case: We report a clinical case of an immature central superior incisor with pulp mortification and acute api- cal periodontitis subsequent to dental trauma, in an 8 year old patient. The pulp Regeneration protocol recommended by the American Endodontics Association was applied. We stimulated a clot formation inside the duct from periapical tissues and after disinfection with a mixture of three antibi- otics mineral trioxide aggregated was finally place coronal to the clot. Thus a sterile matrix was obtained that allowed new tissue's growth. Periodic check-up visits were carried out over a 4 years period. Clinical silence was observed. Tissue formation on duct walls and apical closure were radiograph- ically detected (AU) Conclusion: Regenerative therapy is an alternative for the treatment of immature permanent teeth, in ths clinical case it allowed the reduction of the width of the duct by the opposition of hard tissues and the closure of the apical fora- men improving the forecast of these teeth.

Estudio de la precisión de un localizador de ápice electrónico en dientes monorradiculares / Assessment the accuracy of electronic apex locater in single canal teeth

Introducción: La correcta determinación de la longitud de trabajo es uno de los principales factores determinantes para el éxito de los tratamientos endodónticos. Objetivo: valorar si es precisa la determinación de la longitud de trabajo de un localizador de ápice electrónico en dientes monorradiculares. Métodos: se realizó un estudio experimental exploratorio in vivo, donde se determinó la longitud de trabajo en 141 conductos monorradiculares en pacientes con indicación de exodoncia. Se determinó la longitud de trabajo con un localizador de ápice electrónico iPex II(NSK). Cuando el localizador marcó que la lima se encontraba en el ápice, sin retirar el instrumento del conducto se procedió a fijarla. Se realizó la extracción con precaución y, posteriormente, se desgastó una pared proximal del tercio apical hasta que se pudo observar la lima en el interior del conducto, con auxilio de una lupa. La longitud de trabajo fue aceptable cuando el localizador determinó que estaba entre 0,5-1,5 mm del límite cemento-dentina-conducto; corto cuando estaba a más de 1,5 mm y largo cuando se observó que sobrepasaba el límite cemento-dentina-conducto. Resultados: fue aceptable la precisión en 135 (95,7 por ciento) mediciones y solo 13 (9,2 por ciento) conductos tuvieron inestabilidad, con una relación existente entre la precisión y la inestabilidad de las mediciones. Se observó que 88 (62,4 por ciento) conductos con secreciones obtuvieron un aceptable en la determinación de la longitud de trabajo, mientras que solo 3 (2,1 por ciento) conductos con secreciones tuvieron mediciones cortas. La presencia de secreciones no fue significativa para evaluar la precisión. Conclusiones: Las mediciones de las longitudes de trabajo empleando el localizador estudiado fueron mayormente de precisión aceptable y no inestables. Del mismo modo, la presencia de secreciones en el interior de los conductos radiculares no afectó significativamente la precisión del localizador en cuestión(AU)

Introduction: The correct determination of working length is one of the main determining factors for the success of endodontic treatments. Objective: to assess the accuracy when determining the working length of an electronic apex locator. Objective: To assess the accuracy of the determination of the working length of an electronic apex locator in monoradicular teeth. Material and methods: An exploratory experimental study was carried out in vivo where the working length was taken in 141 monoradicular root canals of patients with indication of extraction. Working length was determined using iPex II electronic apex locator (NSK). When the locator marked that the file was at the apex, without removing the instrument from the duct, it was fixed. The extraction was performed with caution and subsequently a proximal wall of the apical third was worn down until the file was observed inside the duct, observed and studied with the help of a magnifying glass. The working length was acceptable when the locator determined that it was between 0.5-1.5 mm of the cement-dentin-duct limit; short when it was more than 1.5 mm and long when it was observed that it exceeded the cement-dentine-duct limit. Results: The accuracy of 95.7 percent (135) of the measurements was acceptable and only 13(9.2 percent) ducts had instability, with an existing relationship between the accuracy and instability of the measurements. It was observed that 88(62.4 percent) ducts with secretions obtained an acceptable one in the determination of the length of work. Only 3 (2.1 percent) ducts with secretions had short measurements. The presence of secretions was not significant to assess the accuracy. Conclusions: The measurements of the working lengths using the locator studied were, almost entirely, of acceptable precision and were practically unstable. Similarly, the presence of secretions inside the root canals did not significantly affect the accuracy of the localizer in question(AU)

Avaliação de dentes monorradiculares artificiais utilizados para treinamento endodôntico / Evaluation of artificial monoradicular teeth used for endodontic training

Introdução: É desafio do ensino pré-clínico em Endodontia fornecer aos alunos dentes artificiais que reproduzam a morfologia dos dentes humanos. Objetivo: Comparar a morfologia interna e externa de dentes artificiais monorradiculares com dados da literatura sobre dentes humanos. Material e método: Os dentes artificiais foram doados pelos fabricantes: Fábrica de Sorrisos, empresa A, (n=20), e IM do Brasil Ltda., empresa B, (n=20). Foi realizada mensuração do comprimento total do dente e da raiz, da altura, das dimensões vestibulopalatina e mesiodistal da coroa, com paquímetro digital. A descrição morfológica das raízes, coroas e câmaras pulpares foi realizada. A localização topográfica do forame apical principal foi avaliada após exploração dos canais com instrumento endodôntico tipo K #15 até este atingir visualmente o ápice radicular. Os dados foram dispostos em uma planilha de cálculo e realizou-se a análise estatística [ANOVA e pós-teste de Tukey (α=5%)]. Resultado: A amostra de caninos superiores da empresa B apresentou todas as variáveis dentro dos padrões morfométricos descritos na literatura. Em relação às morfologias interna e externa, a amostra de incisivos laterais superiores da empresa A foi a única a apresentar todas as variáveis dentro dos padrões descritos na literatura. Em relação à localização topográfica foraminal, os dentes da empresa A, assim como o canino inferior da empresa B, apresentaram tendência à posição distalizada e centralizada, vindo ao encontro da literatura. Conclusão: Nenhum dente artificial estudado apresentou total similaridade morfológica e morfométrica com a literatura analisada, diferindo em pelo menos uma das variáveis, sendo indicada aos fabricantes uma revisão dos seus modelos.

Introduction: It is a challenge of pre-clinical teaching in Endodontics to provide students with artificial teeth that reproduce the internal and external morphology of human teeth. Objective: To compare the internal and external morphology of single-rooted artificial teeth with data from the literature on human teeth. Material and method: The artificial teeth were donated from two companies: Fábrica de Sorrisos, company A, (n=20) and IM do Brasil Ltda, company B (n=20). Measurement of total tooth length, root, height, buccal-palatal and mesio-distal crown dimensions with digital caliper was performed. The morphological description of the roots, crown and pulp chamber was performed, the last one only after access. The topographic location of the main apical foramen was evaluated after canal exploration with a K #15 endodontic instrument until it visually reached the root apex. The data were arranged in a spreadsheet and statistical analysis was performed (ANOVA, followed by the Tukey post-test (α=5%)). Result: Regarding the morphometric parameters, the upper canine sample from company B presented all variables within the standards described in the literature. Regarding internal and external morphology, the sample of upper lateral incisors from Company A was the only one to present all variables within the standards described in the literature. Regarding the foraminal topographic location, the teeth of Company A, as well as the lower canine of company B, showed a tendency to the distalized and centralized position, in line with the literature. Conclusion: none of the artificial teeth studied showed total morphological and morphometric similarity with the control, differing in at least one of the variables, and a review of their models is indicated to the manufacturers.

Treatment outcomes of pulp revascularization in traumatized immature teeth using calcium hydroxide and 2% chlorhexidine gel as intracanal medication

Abstract Objective Pulp revascularization is an effective treatment for immature necrotic teeth. Calcium hydroxide has been used in pulp revascularization as an intracanal medication due to its antimicrobial action and the non-exhibition of crown discoloration and cytotoxicity for stem cells from the apical papilla. Our study aimed to investigate the clinical success and quantitative radiographic changes of root development in immature traumatized teeth using calcium hydroxide plus 2% chlorhexidine gel as intracanal medication. Methodology In this retrospective study, 16 patients were treated with a standardized pulp revascularization protocol. Calcium hydroxide and 2% chlorhexidine gel were manipulated in a 1:1 (v/v) ratio and inserted into root canals with Lentulo spirals (Dentsply Maillefer, Baillaigues, Switzerland). Patients were followed up for a period from 9 to 36 months for the evaluation of clinical and radiological data. Radiographic measurements of root length, root width, apical diameter, and MTA placement from the apex were quantified using software ImageJ. Wilcoxon test and t-test were used, according to nonparametric or parametric data, respectively, for changes over time in root length, root width, and apical diameter. Results Fifteen teeth survived during the follow-up period (93.75%) and met the criteria for clinical success. Although the changes seem to be very small in many cases, significant increases in the average root length (14.28%, p<0.0001), root width (8.12%, p=0.0196), and decrease in apical diameter (48.37%, p=0.0007) were observed. MTA placement from the apex and age at the time of treatment was not significantly associated with the quantitative radiographic outcomes. Conclusions Pulp revascularization in traumatized immature teeth treated with calcium hydroxide plus 2% chlorhexidine gel as intracanal medication had high success and survival rates, showing periodontal healing and resolution of signs and symptoms. However, concerning the continued root development, the outcomes can still be considered unpredictable.

Agreement Between Working Length Measurements in Primary Teeth Obtained by Radiographs or Apical Locators

Abstract Objective: To perform an in vivo evaluation on the agreement between measurements of working length obtained by conventional radiographic examinations and an apex locator in deciduous teeth with or without root resorption. Material and Methods: Nine canals of teeth from children ranging from 3 to 5 years old were selected. Endodontic access was performed with a spherical diamond tip, the pulp was removed with Kerr-type steel files, and the canal was irrigated with 1% sodium hypochlorite. A file, compatible with the channel gauge, was then used to measure the length of the root canal with the apex locator. Conventional radiographs were also performed and, using a millimeter endodontic ruler, the length of the canal was determined. The differences between the measurements obtained between the two methods were analyzed using the Student's t-test. Results: The mean canal length for conventional radiography was 9.83 mm and 9.67 mm for the apex locator. The results of this study did not show significant differences (p=0.641), independent of the presence or absence of physiological root resorption. Conclusion: The similarity in measurements obtained with X-ray or an apex locator indicates that it is not necessary to use X-rays as a complement to obtain the working length. The use of the apex locator can provide a quicker treatment, reducing the clinical time and stress of the child.

Micro-computed tomographic assessment of the variability and morphological features of root canal system and their ramifications

Abstract Objectives This study assessed the incidence and variability features of root canals system (RCS) and their ramifications according to Pucci & Reig (PR) (1944) and the American Association of Endodontists (AAE) (2017) by micro-computed tomography (μCT). Methodology 500 representative extracted human teeth of each tooth group (n=50) (maxillary/mandibular central and lateral incisors, canines, first and second premolars and molars) were scanned by μCT with a resolution of 26.70 μm. The reconstructed cross-sections images and the visualization of the continuous slices in the transversal axis were performed using DataViewer software. RCS were classified according to Pucci & Reig (main canal, collateral canal, lateral canal, secondary canal, accessory canal, intercanal, recurrent canal) and AAE (main canal, accessory canal, lateral canal). The apical deltas were assessed for both classifications. The prevalence of apical deltas was evaluated using the Chi-squared test (p<0.05). Results According to PR, a higher incidence of lateral canals was observed in maxillary canines (10%), central incisors (8%) and first premolars (6%). Using AAE, the highest incidence of lateral canals was observed in the mandibular first premolars (85%), first and second molars (84%), lateral incisors (67%), canines (59%), and in maxillary first premolars (52%). Regarding accessory canals, the PR showed a frequency in 2% of the maxillary lateral incisors and maxillary and mandibular first premolars and 3% of mandibular first and second molars. On the other hand, the AAE showed the highest incidence of accessory canals in 86% of the maxillary first premolars, 71% in mandibular lateral incisors, 69% in mandibular first premolars, 65% in mandibular canines, and 56% in maxillary canines. The PR showed the lowest incidence of apical deltas for all dental groups when compared with AAE (p=0.004). Interestingly, distal canals in maxillary molars showed a significant discrepancy between classifications (p=0.027). Conclusions μCT enabled accurately describing the RC system and related ramifications, adding to the PR and AAE classifications, with some discrepancies reported for maxillary molars. Clinical Relevance This μCT study enabled a thorough description of the variability among root canals and their ramifications, including clinically relevant details on the presence and location of lateral canals and accessories in all human tooth groups, beyond the currently existing classification systems.