Evaluation of the Ability of 3 Reciprocating Instruments to Remove Obturation Material: A Micro-Computed Tomography Study.

INTRODUCTION: The purpose of this study was to evaluate the ability of the Reciproc, Reciproc Blue, and WaveOne Gold systems to remove filling material during endodontic retreatment of extracted human mandibular premolars. METHODS: Thirty-nine teeth were instrumented with the Protaper Universal System to the F3 file and filled with the Tagger hybrid technique using an F3 gutta-percha cone and AH Plus cement. At the end of this period, the teeth were scanned with micro-computed tomography before and after removal of the filling material from the root canals. The teeth were divided into 3 groups (n = 13) based on the apical volume, depending on the systems used to remove the filling material. Group GR: Reciproc 40/.06; Group GRB: Reciproc Blue 40/.06; and Group GWG: WaveOne Gold 35/.06. The results were statistically analyzed using the tests of Kruskal-Wallis, Duncan, and analysis of variance at a significance level of 5%. RESULTS: The results showed that there were no significant differences between the amounts of filling material removed, either for the apical and middle regions alone or in the overall evaluation for the 3 groups (P = .97). The time evaluation statistically showed that the GR and GWG groups required less time to clean the root canals than the GRB group. CONCLUSIONS: Reciproc R40 files and WaveOne Gold Medium files required less time for endodontic treatment than Reciproc Blue R40 files. There was no difference in the ability to remove obturation material between the 3 instruments. No instrument was able to completely remove the filling material from the root canals.

Effect of obturation technique on dentinal tubule penetration of two tricalcium silicate-based sealers: Ex vivo study.

The aim of this study was to assess by confocal laser microscope the depth of dentinal tubule penetration of two tricalcium silicate-based sealers promoted by two obturation techniques in curved canals compared with AHPlus. One hundred and twenty canals were divided into six groups (n = 20): BCSC-Bio-C Sealer (BC) and single-cone technique (SC); BCCW-BC and continuous condensation wave (CW); TFSC-Total Fill (TF) and SC; TFCW-TF and CW; AHSC-AH Plus (AH) and SC; AHCW-AH and CW. Data were analysed using the three-way ANOVA and Tukey's test (α = 5%). Penetration depth was significantly greater for TFCW than TFSC and greater for AHCW than AHSC (p < 0.05). There was no significant difference between BCCW and BCSC (p > 0.05). The penetration of TF was significantly greater (p < 0.05). The CW technique promoted greater intratubular penetration, except for the BC sealer.

Analysis of the penetration of NaOCl 5.25% into dentinal tubules using different irrigation protocols: An ex vivo study.

The objective of the study was to investigate the 5.25% sodium hypochlorite (NaOCl) penetration into the dentinal tubules after different irrigation methods. Seventy canines were stained with 1% crystal violet and divided into groups (n = 20): GEC-EasyClean; GPUI-E1 Irrisonic ultrasonic insert; GXP-XP-Endo finisher; GPC-conventional irrigation and GNC-stained tooth without irrigation. Axial sections (16×) were assessed and irrigant penetration was quantified as a bleaching halo on the surface of the apical, middle and coronal third. In the apical third, GPUI promoted greater NaOCl penetration (p < 0.05). GXP was better than GEC (p < 0.05), as was GPC (p > 0.05). The GPUI and GXP groups were similar in the middle and coronal third (p > 0.05). GPUI and GXP showed better results than GEC (p < 0.05). GPUI was more effective in the apical third and like GXP in the cervical and middle third.

Ex Vivo Evaluation of the Efficacy of Photodynamic Therapy in Eliminating Enterococcus faecalis from Dentinal Tubules by Confocal Laser Scanning Microscopy.

INTRODUCTION: The aim of the present study was to investigate ex vivo by confocal laser scanning microscopy the antibacterial effect of photodynamic therapy (PDT) on dentinal tubules in the apical 5 mm of human mandibular premolars contaminated with Enterococcus faecalis. METHODS: Thirty-four teeth were standardized to 20 mm and foraminal anatomic diameters using a #20 K-file (Dentsply Maillefer). Samples were contaminated for 21 days and divided into the following 3 experimental groups (n = 10): the PDT group (instrumented canals and PDT), the passive ultrasonic irrigation (PUI) group (instrumented canals and PUI), and the PUI-PDT group (instrumented canals, PUI, and PDT), along with a control group (n = 4) (noninstrumented canals). The canals in the experimental groups were instrumented with ProTaper Next (Dentsply Maillefer) up to X3 and rinsed with EDTA and sodium hypochlorite. The photosensitizer used was 0.01% methylene blue with a preirradiation time of 5 minutes and a diode laser with 4 J energy and a 660-nm wavelength. Cross sections were made 5 mm from the apex of all samples, which were analyzed using confocal laser scanning microscopy. The results were analyzed using the Shapiro-Wilk and Kruskal-Wallis (Dunn) tests. RESULTS: There was a lower percentage of live bacteria in the PUI-PDT group, with a statistical difference compared with the control and PDT groups (P < .05). There was no statistical difference in the percentage of live bacteria between PUI-PDT and PUI (P > .05). CONCLUSIONS: It was concluded that the PUI-PDT association was most effective in disinfecting root canals compared with the control group and PDT.

Micro- CT evaluation of sealers removal by reciprocal instrumentation followed by continuous ultrasonic irrigation in teeth with oval root canals.

Background: The ability of the Reciproc system (R40) followed by continuous ultrasonic irrigation (CUI) to remove filling material from oval root canals of mandibular premolars filled with gutta-percha and AH Plus or Bio-C Sealer was evaluated by microtomography (micro-CT). Material and Methods: The straight and oval root canals of 42 mandibular premolars were prepared with the ProDesign R 35.05 reciprocal file and randomly divided into two groups according to the material used to fill the canals (n=21): Group AH - Master Cone and AH Plus; Group BC - Master Cone and Bio-C Sealer. After filling and provisional sealing, the teeth were stored at 100% relative humidity and a temperature of 37°C for 30 days. The filling material was then removed with an R40 file. The material was considered completely removed when the R40 file reached the working length (WL), and no remaining filling material was visible on the canal walls. CUI was then performed. The teeth were scanned by micro- CT before and after removal of the filling material. The remaining filling material was measured in mm in the last apical 5 mm. The data were analyzed with the nonparametric Friedman test and subsequently with the Dunn test. The Mann-Whitney U test was also performed. Statistical significance was accepted at the 5% level. Results: After instrumentation with the Reciproc R40, the volume of residual filling material was significantly greater in the BC group than in the AH group (P = 0.035). After CUI, there was no difference in the volume of residual material between the two groups (P = 0.705). Conclusions: Bio-C sealer was more difficult to remove with the Reciproc file than AH Plus. CUI improved the removal of residual filling material regardless of sealer type. However, no technique was able to completely clear the canals of filling material. Key words:Bioceramic cement, CUI, micro-CT, reciproc, retreatment.

The Effectiveness of Three Irrigation Systems in the Enterococcus faecalis Reduction after Instrumentation with a Reciprocating Instrument.

OBJECTIVE: This study aimed to analyze the effectiveness of three irrigation systems: EndoActivator, passive ultrasonic irrigation (PUI), and Easy Clean in the reduction of Enterococcus faecalis, after instrumentation with the reciprocating system, through microbiological collection and culture method. MATERIALS AND METHODS: A total of 60 extracted human lower premolars were used and standardized at 16 mm in length. The teeth were accessed, contaminated with E. faecalis, and incubated for 21 days at 37°C. Initial collections (S1) were made with an absorbent paper cone to confirm the contamination; subsequently, instrumentation was performed with WaveOne Primary. The teeth were divided into four groups according to the final irrigation protocol (n = 15): group 1. EndoActivator; group 2, PUI; group 3, Easy Clean; and group 4, control group irrigated with saline solution sterile and without agitation. In the final irrigation, the agitation of the 17% ethylene amine tetra-acetic acid (EDTA) solutions was used, then 2.5% sodium hypochlorite (NaOCl); in both for this, three cycles of 20 seconds each. After the chemical-mechanical preparation and agitation of the irrigating solutions, the final collections (S2) for counting the colony-forming units (CFU/mL) occurred. RESULTS: The Kruskal-Wallis test revealed that all the agitation systems reduced by 100% and the control group by 65.7%. CONCLUSION: The control group presented a significantly higher amount of CFU/mL after the chemical-mechanical preparation than the other groups, which were similar to each other (p > 0.05).

Procedimento endodôntico regenerativo usando fibrina rica em plaquetas e leucócitos associada à cirurgia apical: relato de caso / Regenerative endodontic procedure using leukocyte- and platelet-rich fibrin associated with apical surgery: case report

ntrodução: A cirurgia parendodôntica é uma alternativa ao tratamento endodôntico convencional, principalmente em casos envolvendo lesões perirradiculares associadas a processos osteolíticos, em que a terapia endodôntica convencional ou seu retratamento não obtiveram sucesso. Novos métodos terapêuticos têm ganhado espaço na clínica odontológica para esse tipo de caso, entre os quais se destaca a fibrina rica em plaquetas e leucócitos, que, ao concentrar e permitir uma liberação mais prolongada dos fatores de crescimento, promove uma modulação do processo reparador. Esse processo é baseado na otimização da regeneração tecidual através da inserção da membrana de fibrina. Objetivo: O objetivo do presente trabalho é apresentar, por meio do relato de um caso clínico, a utilização de fibrina rica em plaquetas e leucócitos em cirurgia parendodôntica, com intuito de reparo ósseo. Resultados: O acompanhamento clínico e tomográfico foi realizado após 190 dias, momento no qual foi constatada ausência de sintomatologia, bem como completo reparo da lesão e restabelecimento do osso cortical vestibular, além de ausência de lesão detectável em tomografia. Conclusão: No caso clínico relatado, houve uma completa regeneração tecidual da área envolvida na lesão (AU).

Introduction: Parendodontic surgery is an alternative to conventional endodontic treatment, especially in cases involving periradicular lesions associated with osteolytic processes, in which conventional endodontic therapy or retreatment was not successful. New therapeutic methods for the treatment of these cases have ground in clinical dentistry . For example, leukocyteand platelet-rich fibrin which has a higher concentration and more prolonged release of growth factors, modulates the repair process. This process is based on the optimization of tissue regeneration through the insertion of fibrin membrane. Objective: The objective of this study is to report a case in which leukocyte- and platelet-rich fibrin associated with parendodontic surgery was used for bone repair. Results: Clinical and tomographic follow-up was performed after 72 days, which revealed absence of any symptoms, complete repair of the lesion, buccal cortical bone regeneration, and absence of detectable lesion on tomography. Conclusion: There was complete tissue regeneration at the lesion site(AU).

Effect of immersion in sodium hypochlorite on the cyclic fatigue resistance of three rotary instruments.

CONTEXT: It is essential to know if the immersion in sodium hypochlorite (NaOCl) influences the cyclic fatigue resistance of nickel-titaniumm (NiTi) files. AIM: This study was aimed to evaluate the resistance to the cyclic fatigue of three NiTi systems, as well as the influence of 5.25% NaOCl on their resistance. METHODS: Files from the Sequence Rotary File (MK life, Porto Alegre, Brazil), ProTaper Next (PTN) (Dentsply, Maillefer, Baillagues, Switzerland), and HyFlex EDM (Coltène Whaledent, Allstatten, Switzerland) systems were tested and separated into Group 1)-without immersion in NaOCl solution and Group 2 and Group 3-immersed in 5.25% NaOCl solution, for 1 min, and 5 min, respectively. All instruments were submitted to the cyclic fatigue test. Images of the instruments were observed by scanning electron microscopy, to evaluate the type of defect presented on the fractured surface. The test performed for the analysis of two independent factors was a two-way analysis of variance. RESULTS: HyFlex EDM presented a greater number of cycles until fracture when compared to others (P < 0.001). The control group showed a greater number of cycles until fracture than the same instruments submitted to NaOCl (P < 0.001). Sequence instruments showed the lowest values of cycles until fracture (P < 0.001). There was no statistically significant difference between treatments (P = 0.998). PTN, showed intermediate values of fracture resistance when compared to the HyFlex EDM and sequence instruments (P < 0.001), but without intragroup differences (P = 0.437). CONCLUSIONS: Hyflex EDM instruments were the most resistant to cyclic fatigue.

Estudo in vitro do nível de escoamento de cinco cimentos endodônticos: Endofill, AH Plus, MTA Fillapex, Sealer 26 e Pulp Canal Sealer EWT / In vitro study of the flow rate of five root canal sealers: Endofill, AH Plus, MTA Fillapex, Sealer 26 and Pulp Canal Sealer EWT

Objetivo: o objetivo desse trabalho foi estudar, in vitro, o nível de escoamento dos cimentos Endofill, AH Plus, MTA Fillapex, Sealer 26 e Pulp Canal Sealer EWT. Métodos: os cimentos foram manipulados de acordo com as recomendações dos fabricantes. A determinação do escoamento foi conseguida em conformidade com a especificação #57 da ADA (American Dental Association). Na comparação entre os grupos, foi realizada a ANOVA (análise de variância) e posterior teste de Tukey, com nível de confiança de 95%. Resultados: os resultados mostraram que o cimento MTA Fillapex apresentou o maior escoamento entre os cimentos estudados e o cimento AH Plus foi o único que apresentou escoamento estatisticamente significativo após 24 e 48 horas. Conclusão: concluiu-se que todos os cimentos avaliados estão em conformidade com a especificação #57 da ADA. No entanto, o cimento MTA Fillapex foi superior aos outros cimentos analisados, no que se refere ao poder de escoamento. O desempenho clínico do cimento obturador está diretamente relacionado à sua capacidade de penetrar nos túbulos dentinários e canais laterais; daí a importância do estudo do escoamento dos cimentos endodônticos.

Revascularização pulpar: relato de caso clínico / Pulp revascularization: a clinical case report

A revascularização é uma abordagem alternativa para o tratamento de dentes com rizogênese incompleta e necrose pulpar, com bases biológicas. Ao contrário de técnicas de barreira apical artificial, a rizogênese permite a continuação do desenvolvimento radicular e o restabelecimento da vitalidade pulpar. Apresentar a importância do diagnóstico e do plano de tratamento, e um protocolo de tratamento que envolve o procedimento de revascularização pulpar, por meio de um caso clínico de dente com rizogênese incompleta e necrose pulpar. Depois da instrumentação passiva das paredes do canal e medicação com hidróxido de cálcio, foi realizada indução de sangramento, com posterior formação de coágulo e colocação de barreira de MTA. O selamento coronário foi realizado com resina composta. No controle clínico e radiográfico, observou-se que o dente apresentava-se assintomático e que a lesão tinha desaparecido. Concluiu-se que esse tratamento promove o espessamento das paredes dentinárias, evitando que o dente fique fragilizado.

Avaliação da infiltração marginal apical em dentes retro-obturados com MTA/água e MTA/FillApex: estudo em dentes avulsionados / Evaluation of apical marginal leakage in teeth retrofilled with MTA-water and MTA-Fillapex: a study in avulsed teeth

Introdução: como o sucesso da terapia cirúrgica periapical depende do adequado selamento apical, o MTA e a melhor indicação como material retro-obturador. Objetivo: avaliar se a manipulação do MTA com o cimento FillApex altera sua capacidade de selamento apical, por meio da infiltração apical com rodamina B a 1%. Métodos: usando o sistema rotatório Protaper, 50 raízes com canais retos foram preparadas ate o instrumento F5 e obturadas por meio de uma técnica de termoplastificação e cimento. Os espécimes foram divididos em quatro grupos: os Grupos I, II e III sofreram apicectomia e foram retropreparados com ponta de ultrassom; o Grupo IV não sofreu apicectomia, nem retropreparação, servindo como controle positivo. O Grupo I foi retro-obturado com MTA-água; Grupo II foi retro-obturado com MTA-FillApex; o Grupo III não foi retro-obturado, servindo como controle negativo. As raízes do Grupo IV foram revestidas com duas camadas de esmalte para unhas na cor vermelha; e as raízes dos Grupos I, II e III também foram revestidas, exceto na região apicectomizada, e imersas em 3 ml de solução de rodamina B a 1%,em recipientes padronizados e identificados, por 8 dias, em estufa, a temperatura de 37°C e 100% de umidade. Para avaliar o nível de corante infiltrado, os espécimes foram clivados no sentido longitudinal, fotografados e encaminhados a três mestres em Endodontia, que analisaram quatro níveis de infiltração: zero; 0 a 1 mm; 1 a 2 mm; 2 a 3 mm. Resultados: os resultados mostraram que associação MTA-FillApex teve menor infiltração marginal do que o MTA-água.

Avaliação da capacidade de limpeza de dois sistemas rotatórios de níquel-titânio: ProTaper Universal e ProDesign S tratado termicamente / Evaluation of cleaning ability of two rotary nickel-titanium systems: ProTaper Universal and heat treated ProDesign S

Introdução: a finalidade da instrumentação endodôntica é promover a limpeza e modelagem do canal radicular, preparando-o para posterior obturação definitiva. Objetivo: o objetivo desse estudo foi avaliar, in vitro, a qualidade da limpeza de blocos de canais simulados, instrumentados por dois sistemas rotatórios de níquel-titânio. Métodos: foram utilizados 20 blocos de acrílico (canais simulados), que foram separados em dois grupos com 10 cada. Foi injetada tinta nanquim nos canais simulados, os quais foram cobertos com papel laminado, para não haver influência na instrumentação. Os blocos do Grupo 1 foram instrumentados utilizando-se a sequência operatória original do sistema ProTaper Universal, até o instrumento F3; para irrigação foram utilizados 5ml de solução salina a cada troca de instrumento. Os blocos do Grupo 2 foram instrumentados pelo sistema ProDesign S, tratados termicamente até o instrumento 30.05 e, também, irrigados com 5ml de solução salina. Após o término das instrumentações, os blocos foram fotografados e analisados, quanto à limpeza, por três mestres em Endodontia. Conclusão: nas condições experimentais em que essa pesquisa foi conduzida, não se evidenciou nenhuma diferença estatística na capacidade de limpeza entre os dois sistemas estudados