Quality of Root Canal Fillings and Procedural Errors for In Vivo Studies Prepared in Different Clinical Settings and with Rotary Systems: A Systematic Review.

BACKGROUND This systematic review of the literature aimed to identify published studies and evaluate them on the quality of root canal fillings (RCF) and procedural errors with rotary systems for in vivo studies prepared for different clinical settings. MATERIAL AND METHODS A full literature exploration was conducted in Clarivate Analytics' Web of Science, Elsevier's Scopus, Embase, and PubMed for studies published between January 2020 and March 2024. A manual search was also performed by reviewing the references of selected papers. The following keywords were used: quality of root canal filling(s) OR quality of root canal obturation, root canal obturation OR endodontic treatment, clinical setting (academic, private, governmental), AND/OR procedural errors and rotary instrumentation. RESULTS Sixteen clinical studies were included in this review. The acceptance percentages for obturation length, density, and taper were 76.3%, 74.7%, and 82.5%, respectively, indicating significantly high, good ratios. The overall RCF recorded showed that 68.2% of root canal obturations were considered acceptable. Acceptable rates remained higher than unacceptable rates in academic, hospital, and private settings, and percentages ranged from 65.2% to 93.0%. Only 5 studies reported procedural errors, namely, ledge formation, separated instruments, apical perforation, transportation, lateral perforation, and root/foramen perforation. CONCLUSIONS Using rotary instruments for different root canal treatment steps as instrumentation and obturations is highly recommended. Among different clinical setting and practice, these instruments resulted in a good and acceptable RCF, overall quality performed by those instruments, and few procedural errors.

CTZ and Calcium Hydroxide Pastes Did Not Cause Hepatic and Renal Alterations in Mice

ABSTRACT Objective: To evaluate the possible renal and hepatic alteration by root canal filling pastes in mice. Material and Methods: Fifty-four mice were divided into nine groups and received one polyethylene tube implant containing two filling pastes (CTZ or calcium hydroxide pastes). Empty polyethylene tubes were used as a negative control. All tubes were implanted subcutaneously in the back of the mice. After time intervals of 7, 21, and 63 days, 1.5 mL of blood was collected by cardiac puncture, and serum samples were used for serological testing. Urea, creatinine, aspartate transferase (AST), alanine transferase (ALT), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT) were evaluated. Data were analyzed by 2-way ANOVA (p<0.05). Results: When comparing CTZ and calcium hydroxide pastes and empty tubes and experimental time intervals, no significant differences in the results were found for any of the biochemical parameters analyzed (p>0.05). No differences were observed in the interactions (material*experimental time intervals) and the biochemical parameters analyzed (p>0.05). Conclusion: CTZ and calcium hydroxide pastes did not cause hepatic and renal alterations in mice, demonstrating the pastes' safety.

Continuous Wave of Condensation Improves the Filling of Curved Canals: a Micro-CT Study / La condensación de onda contínua mejora el selle de canales curvos: un estudio de micro-CT

Abstract The aim of this study was to compare the filling capacity in curved root canal using a new continuous wave of condensation technique (Termo Pack II, Easy Dental Equipments, Brazil) or lateral compaction. The percentage of voids in the filling of mesial root canals of mandibular molars was assessed by micro-computed tomography (micro-CT). Mesial root canals (n=24) of mandibular molars with a degree of curvature between 20° and 40° were prepared using rotary system (ProDesign Logic, Easy, Brazil) up to #35, .05 taper. The root canals were filled by using the continuous wave of condensation system or lateral compaction and AH Plus sealer (n=12). Scanning at 9 µm was performed after preparation and after filling by using micro-CT SkyScan 1176. The volumetric percentage of filling material and voids (total length and in each root canal third) were calculated. Data were analyzed using ANOVA/ Tukey and Student's t tests (α=0.05). Before the filling techniques, the root canals volume after preparation was similar (p>0.05). The root canals filled by the continuous wave of condensation technique presented the lowest percentage of voids, and the greatest percentage of filling material in total length and thirds (cervical, middle and apical) (p<0.05). Both techniques were not able of completely filling the root canals. The continuous wave of condensation technique Termo Pack II promoted better root canal filling in curved root canals, when compared with lateral compaction.

Resumen El objetivo de este estudio fue comparar la capacidad de obturación en conductos radiculares curvos utilizando una nueva técnica de condensación de onda continua (Termo Pack II, Easy Dental Equipments, Brasil) vs compactación lateral. El porcentaje de brechas en la obturación de los conductos radiculares mesiales de los molares mandibulares se evaluó mediante microtomografía computarizada (micro-CT). Se prepararon conductos radiculares mesiales (n=24) de molares mandibulares con un grado de curvatura entre 20° y 40° utilizando un sistema rotatorio (ProDesign Logic, Easy, Brasil) al #35, conicidad 0,05. Los conductos radiculares se obturaron utilizando un sistema de condensación de onda contínua o compactación lateral y cemento AH Plus (n=12). Se realizó un escaneo de 9 µm después de la preparación y después de la obturación usando el micro-CT SkyScan 1176. Se calculó el porcentaje volumétrico de material de obturación y vacíos (longitud total y en cada tercio del conducto radicular). Los datos se analizaron utilizando las pruebas ANOVA/Tukey y t de Student (α=0,05). Antes de las técnicas de obturación, el volumen de los conductos radiculares después de la preparación fue similar (p>0,05). Los conductos radiculares obturados con la técnica de condensación por onda contínua presentaron el menor porcentaje de vacíos y el mayor porcentaje de material de obturación en longitud total y en tercios (cervical, medio y apical) (p<0,05). Ambas técnicas no fueron capaces de llenar completamente los conductos radiculares. La técnica de condensación de onda contínua Termo Pack II promovió un mejor relleno del conducto radicular en conductos radiculares curvos en comparación con la compactación lateral.

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).

Evaluation of apical transportation and apical root sealing in root canals prepared with mtwo rotary system with and without apical enlargement ­ an in vitro study

The aim of this study was to evaluate apical transportation and apical root canal sealing after root canal filling in human teeth prepared with MTwo® Rotary System with and without apical foramen enlargement. Twenty mandibular premolars were divided into two groups (n=10). Group 1 had root canals prepared 1mm beyond the apical foramen. Group 2 had root canals prepared 1mm below the root canal length. After chemo-mechanical preparation, samples were submitted to scanning electronic microscopy. Apical foramen images had 75x magnification at standardized positions, allowing measurements from the apical foramen area before and after root canal preparation, and after root canal filling. Apical foramen shape and apical transportation, as well as its level of circumferential filling after root canal preparation were accessed using the Image Subtraction System. Scanning electronic microscopy analysis demonstrated that samples of Group 1 showed larger foraminal diameter than samples of Group 2 (p<0.05). Apical foramen transportation was statistically different between Groups 1 and 2 (p=0.0108). Furthermore, the apical foramen sealing also differed statistically between groups 1 and 2 (p=0.0007) and 100% of samples of Group 1 showed apical root canal sealing. Apical root canal sealing was more effective when the root canal was prepared with apical foramen enlargement, even when the apical transportation was detected.

Evaluation of the Effect of the Intensity and Occurrence of Postoperative Pain of Resin-Based and Bioceramic Root Canal Sealers: A Systematic Review and Meta-Analysis of Randomized Controlled Trial Studies

ABSTRACT Objective: To evaluate resin- and bioceramic root canal sealers affect postoperative intensity and pain occurrence. Material and Methods: From the electronic databases, PubMed, Cochrane Library, Embase, ISI have been used to perform systematic literature until September 2020. Electronic titles were managed using the Endnote X8 software. They performed searches with mesh terms. Two reviewers blindly and independently extracted data from studies that included data for data extraction. Results: A total of 186 potentially relevant titles and abstracts were found. Finally, four studies were included. Pain score was (RR = -0.20; 95% CI -1.09-0.68; p= 0.65). This result showed no statistically significant difference for the resin-based and bioceramic root canal sealers after 24 hours between the VAS scores. Conclusion: Postoperative pain was low in Patients requiring root canal retreatment and obturated with resin-based or bioceramic-based sealers without extrusion beyond the apex. No differences were observed between postoperative pain in resin-based and bioceramic root canal sealers 24 and 48 hours postoperatively.

Tratamiento regenerativo de lesión interproximal consecuente a fractura del tercio medio en diente permanente joven / Regenerative treatment of interproximal lesion following middle third fracture in a young permanent tooth

Se presenta un caso clínico de fractura radicular del tercio medio, de pieza 2.1 con desplazamiento de los cabos de fractura. Es tratado con un novedoso procedimiento terapéutico, mediante la utilización de un biomaterial de tercera generación osteoconductor, osteogénico y osteoinductor. Se obtiene la reparación del tejido conectivo interproximal y la formación de tejido calcificado (AU)

We present a clinical case of root fracture of the middle third, piece 2.1 with displacement of the fracture ends. It is treated with a novel therapeutic procedure, using a thirdgeneration osteoconductive, osteogenic and osteoinductive biomaterial. Interproximal connective tissue repair and calcified tissue formation are obtained (AU)

Qualitative Analysis of Root Canal Treatments performed by Undergraduate Students: A Retrospective Study

ABSTRACT Objective: Toanalyze the technical quality of endodontic treatment carried out at the undergraduate dental clinics. Material and Methods: Random radiographic records of 92 patients' were selected who received endodontic treatment by the undergraduate students from June 2018 to July 2019. The quality of root canal filling was determined in relation to the adequate density, length, and taper. Statistical analysis was performed by using GraphPad (Prism 5), and to determine the association between different variables Chi-square test was used. Results: Adequate technical quality of canal obturation conducted by the undergraduate students was found in less than 65% of the cases. The frequency of adequate root canal taper was significantly greater in maxillary teeth (75%) as compared to mandibular teeth (33%); however, adequacy of acceptable density was found more in maxillary teeth (62%) as compared to mandibular teeth (55%).A statistically significant difference was seen in the quality of root canal fillings between anterior and posterior teeth (p=0.001). Conclusion: The root canal therapy performed by undergraduate students was less than optimum in terms of technical quality. Hence, it is suggested that the endodontic training courses delivered at pre-clinical and clinical levelsfor undergraduate students must be thoroughly revised.

Success Rate of Contemporary Regenerative Endodontic Therapy and the Expected Outcomes of the Endodontic Microsurgery: A Systematic Review and Meta-Analysis

ABSTRACT Objective: To examine the level of the accumulating success of the modern Resin-Based Endodontic Surgery (RES) and comparison with Endodontic Microsurgery (EMS) and finally offer a replacement at the predicted final results of EMS. Material and Methods: MEDLINE, PubMed, Cochrane Library, Embase, ISI, Google Scholar have been utilized as electronic databases for systematic literature until 2019. Therefore, Endnote X9, which can be provided in the market, has been applied to manage the electronic titles. Searches have been made with keywords "Endodontic Microsurgery OR EMS", "Resin-Based Endodontic Surgery OR RES", "Regenerative Endodontic Therapy", "Root-End Filling", "Root-End Surgery", "Periapical Surgery" and "Endodontics". Thus, this systematic review has been conducted concerningthe basic investigation of the PRISMA Statement-Preferred Reporting Items designed for the Meta-analyses and Systematic Reviews. Results: A total of RES =19 and EMS =31 with potential pertinent abstracts and topics were discovered in manual and electronic searches. Then, three articles for RES and four studies for EMS publications satisfied our inclusion criteria necessary for systematically reviewing the studies. The analysis showed the success rate for EMS as equal to 1.16 times the probability of the success rate for RES. Conclusion: Micro-surgical procedures superiorly achieved the predictable high success rate for the Root-end surgery compared to conventional methods.

Antibacterial and Solubility Analysis of Experimental Phytotherapeutic Paste for Endodontic Treatment of Primary Teeth

ABSTRACT Objective: To evaluate the antibacterial effect and the solubility of experimental root canal filling pastes containing the phytoconstituents terpineol and cinnamaldehyde. Material and Methods: Minimum Inhibitory Concentration (MIC) of each phytoconstituent was determined against Enterococcus faecalis. Five groups of antibiotic pastes based on zinc oxide were obtained by mixing: only terpineol, only cinnamaldehyde, terpineol and cinnamaldehyde combined, chlorhexidine (antibiotic control), and CTZ paste (control paste). Antibacterial activity was analyzed through direct contact test within 24 and 72 hours. Solubility was evaluated by spectrophotometry within 48 and 144 hours. Antibacterial activity data were analyzed descriptively, and solubility data was analyzed using ANOVA and Tukey tests (p<0.05). Results: The MIC obtained for terpineol and cinnamaldehyde were, respectively, 2000 µg/mL and 500 µg/mL. After 24h, only the terpineol paste did not inhibit E. faecalis growth. After 72h, all groups inhibited E. faecalis growth. After 48h, the highest solubility was verified in the terpineol paste (p<0.05), and no differences were detected among other groups (p>0.05). After and 144h, highest solubility was observed in the terpineol paste (p<0.05), followed by the CTZ paste (p<0.05). No differences were detected for cinnamaldehyde, terpineol+cinnamaldehyde and chlorhexidine pastes (p>0.05). Conclusion: Pastes containing cinnamaldehyde or terpineol+cinnamaldehyde showed antibacterial activity against E. faecalis similar to CTZ paste, with lower solubility.

Relación entre la conformación del conducto radicular y las técnicas de obturación tras la instrumentación con TruNatomy, Wave One Gold y ProTaper Gold en conductos curvos simulados de EndoTraining Blocks / Relation between canal shape and filling techniques after instrumentation with TruNatomy, WaveOne Gold, and ProTaper Gold in simulated curved canals from Endo Training Blocks

OBJETIVO: Evaluar en conductos simulados instrumentados con técnicas mecanizadas, la profundidad de penetración de los instrumentos para la obturación con diferentes técnicas y sistemas. MATERIALES Y MÉTODOS: Se emplearon 30 conductos simulados divididos en 3 grupos de 10. Grupo 1. Instrumentado con TruNatomy Prime, Grupo 2. Instrumentado con Wave One Gold Primary y Grupo 3. Instrumentado con ProTaper Gold F2. En cada grupo se realizaron 4 pruebas. 1. Nivel de penetración del atacador manual 9P de 0.6 mm Schilder; 2. Nivel de penetración del atacador Calamus #40 .03; 3. Nivel de penetración de la cánula Calamus 23G; 4. Nivel de penetración del verificador SV20 de GuttaCore para el Grupo 1 y el SV25 para los grupos 2 y 3. Para la evaluación estadística se utilizó análisis de variancia y prueba de Tukey para comparaciones múltiples. Nivel de significación P < 0,05. RESULTADOS: En las pruebas 1,2 y 3, las preparaciones con TruNatomy mostraron una penetración menor de los instrumentos de obturación comparada a las de WaveOne Gold y ProTaper Gold. En la prueba 4, el verificador SV20 fue adecuado con el TruNatomy, en tanto el SV25 lo fue para WaveOne Gold y ProTaper Gold. El análisis estadístico de las pruebas 1,2 y 3 mostró diferencia significativa entre TruNatomy y los otros grupos. En la prueba 4 todos los verificadores penetraron adecuadamente. CONCLUSIONES: 1.- La preparación con TruNatomy Prime dificultó la penetración de los dispositivos necesarios para la obturación con las diferentes técnicas. Para el GuttaCore, el verificador empleado debería ser de un calibre menor al instrumento de prepa-ración. 2.- Los instrumentos WaveOne Gold Primary y ProTaper Gold F2 produjeron una conformación que permitió una penetración mayor de los dispositivos de obturación. Los verificadores GuttaCore de dichos sistemas coincidieron con los instrumentos de preparación

OBJECTIVE: The aim of the study was to evaluate depth of penetration of the instruments used in different obturation techniques and systems in simulated curved canals prepared with three different techniques. MATERIALS AND METHODS: Thirty with simulated curved canals were used and divided into three groups. Group 1 Was instrumented with TruNatomy Prime. Group 2. Was instrumented with WaveOne Gold Primary. Group 3. Was instrumented with ProTaper Gold F2. In each group four tests were carried out. 1. for depth of penetration of manual plugger 9P 0.6 mm Schilder; 2. for depth of penetration of the Calamus Dual plugger #40 .03; Test 3. for depth of penetration of the Calamus Dual cartridge 23G. Test 4. for depth of penetration of the GuttaCore SV20 verifier for group 1 and SV25 verifier for groups 2 and 3. The results were statistically evaluated by the analysis of variance and Tukey multiple comparison test. The level of significance was set at P < 0.05. RESULTS: In tests 1, 2 and 3 canals prepared with TruNatomy showed lower penetration depth than groups prepared with WaveOne Gold Primary and ProTaper Gold. In test 4 verifier SV20 was adequate for TruNatomy, while SV25 was for WaveOne Gold and ProTaper Gold. Statistical analysis of tests 1,2 and 3 showed a significant difference between TruNatomy and the other groups. In test 4, all the verifiers penetrated adequately. CONCLUSIONS:1.- The use of TruNatomy Prime in simulated curved canals limited the penetration of the devices from the different obturation techniques. GuttaCore verifier should be selected one caliber less than the instrument used. 2. WaveOne Gold Primary and ProTaper Gold F2 shaped a canal that allowed deeper penetration of the obturation devices. GuttaCore verifiers employed corresponded with the instruments used

Tiempo y eficacia de diferentes sistemas y dinámicas para penetrar la obturación de GuttaCore en el retratamiento en conductos curvos simulados de EndoTraining Block / Time and efficacy of different systems and dynamics to penetrate the GuttaCore obturation in the retreatment of simulated curves canals in EndoTraining Blocks

Objetivo: Evaluar el tiempo y la eficacia de diferentes instrumentos y dirección de movimiento para perforar el GuttaCore y alcanzar la longitud de trabajo en conductos simulados curvos. Material y métodos: Treinta EndoTraining Blocks, fueron instrumentados hasta la longitud de trabajo, con el sistema de instrumentación reciprocante WaveOne Gold Primary y obturados con GuttaCore Primary y cemento sellador AH Plus. Las muestras fueron divididas en 3 grupos de 10 especímenes. Grupo 1: Des-obturados con ProTaper Gold F2 en giro rotatorio horario. Grupo 2: Desobturados con WaveOne Gold Primary en giro rotatorio antihorario. Grupo 3: Desobturados con WaveOne Gold Primary en movimiento recíproco. El tiempo de penetración del instrumento hasta la longitud de trabajo fue registrado con un cronómetro digital. Posteriormente, cada EndoTraining Block fue evaluado en un microscopio óptico para observar el trayecto de penetración del instrumento dentro del bloque de GuttaCore. Los instrumentos fueron descartados tras dos usos y observados al microscopio óp-tico para analizar su superficie. El tiempo registrado se evaluó por medio del análisis de variancia y prueba de Tamhane para comparaciones múltiples. Para las variables morfología del conducto y estado del instrumento se utilizó la prueba de chi-cuadrado o la prueba exacta de Fisher. Resultados: Los grupos 1 y 2 mostraron un tiempo significativamente menor en la penetración del material obturador (P<0,05) que el grupo 3. Los transportes de la morfología de los conductos simulados no mostraron diferencias significativas entre grupos (P>0,05). En relación al estado de los instrumentos, los grupos 1 y 2 mostraron diferencias significativas respecto al grupo 3 (P= 0,02). Conclusiones: Los sistemas ProTaper Gold en giro horario y WaveOne Gold en giro antihorario fueron más eficientes que el WaveOne Gold en movimiento recíproco

Objective: The aim of this study was to evaluate the time and efficacy to penetrate the GuttaCore and reach the working length in simulated curved canal using different instruments and kinematics. Material and methods: Thirty Endo training Blocks were instrumen-ted with WaveOne Gold Primary and obturated with GuttaCore Primary and AH Plus sealer. Blocks were divided into 3 groups of 10 samples each. Group 1: Desobturated with ProTaper Gold F2 in clockwise rotation. Group 2: Desobturated with WaveOne Gold Primary in counterclockwise rotation. Grupo 3: Desobturated with WaveOne Gold Primary reciprocating motion. Time to reach the working length was recorded by a digital chronometer. After this procedure all the Endo Training Block were evaluated under an optic microscope in order to analyze the canal morphology. Instrument were used twice and then were discarded and observed under an optic microscope to determine the file condition. Registered time was evaluated by the analysis of variance and Tamhane test for multiple comparisons. Regarding to the variables of canal morphology and the final instrument condition, chi square test or Fisher exact test were used grouping data when necessary. Results: Groups 1 and 2 showed significantly shorter time (P<0,05) than group 3 in penetrating the filling material. Alteration of the canal morphology in simulated canals was not significant between groups (P>0,05). Regarding to the final instrument condition, groups 1 and 2 showed statistical difference respect of group 3 (P=0,02). Conclusions: ProTaper Gold in clockwise rotation and WaveOne Gold in counterclockwise rotation were more efficient than Wa-veOne Gold in reciprocation motion

Influência do retratamento na formação de microtrincas dentinárias em molares inferiores obturados com o cimento biocerâmico total fill: análise por micro-ct / Influence of retreatment on the formation of dentinal microcracks in lower molars filled with total bioceramic cement fill: micro-ct analysis

Objetivo Este estudo teve como objetivo avaliar a incidência de microtrincas dentinárias após a remoção do material obturador utilizando o cimento biocerâmico TotalFill BC através de análises de microtomografia computadorizada (micro-CT). Metodologia Vinte raízes mesiais de molares mandibulares foram obturadas com guta percha e cimento Total Fill BC e em seguida o material obturador foi removido. As amostras foram escaneadas por micro-CT antes do preparo químico-mecânico, após a obturação e posteriormente a remoção do material obturador. As imagens transversais das raízes mesiais obtidas após a obturação foram analisadas e comparadas com as imagens após a remoção do material obturador, utilizando o programa Image J. Resultados Dos 24.444 cortes transversais analisados, 5,67% apresentaram algum defeito de dentina, sendo que nas imagens iniciais foram encontradas 0,51%, nas imagens pós obturação 2,58%, e nas imagens obtidas após a desobstrução 2,58%. Nas análises comparando as imagens iniciais e pós-obturação foram observados 1,65% dos cortes com novas microtrincas. Todos os defeitos dentinários identificados na análise das imagens obtidas após a remoção do material obturador já estavam presentes nas imagens correspondentes obtidas após a obturação. Desta forma, nenhuma nova microfissura foi observada após remoção do material obturador. Conclusão O estudo não visualizou a produção de novas microtrincas dentinárias durante a fase de desobstrução do retratamento endodôntico. (AU)

Aim The present study aimed to evaluate the frequency of dentinal micro-cracks after removal of the filling material using the TotalFill BC bioceramic-based root canal sealer through microcomputed tomography (micro-CT) analyzes. Methodology Twenty mesial roots of mandibular molars were filled with gutta-percha and TotalFill BC sealer and then the filling material was removed. The specimens were scanned by micro-CT, before instrumentation, after filling and after removal of the filling material. Subsequently, the transversal images of the mesial roots obtained after filling were analyzed and compared with that obtained after removal of the filling material, using the program Image J. Results Among the 24.444 cross sections analyzed, 5,67% presented some type of defect, with 0.51% in the initial images, 2.58% in the post-filling images and 2.58% in the final images. In the analysis comparing the initial images with the post-filling, 1,65% of the sections presented new microcracks. All the dentin defects identified in the analysis of the images obtained after the removal of the filling material were already present in the corresponding images obtained after the filling. Therefore, no new microcrack was observed after removal of the filling material. Conclusion The study did not visualize the production of new dentin microcracks during the removal of filling material in the endodontic retreatment. (AU)

Análise de sistemas reciprocantes quanto a produção de desvios e remoção de material obturador em canais radiculares: estudo in vitro / Analysis of reciprocal systems regarding the production of deviations and removal of filling material in root canals: in vitro study

O retratamento endodôntico é um procedimento realizado quando o tratamento anterior tem insucesso e visa reverter os processos infecciosos, removendo completamente o material obturador permitindo uma nova limpeza, modelagem e reobturação dos canais radiculares. Com vistas a melhoria das taxas de sucesso e eficiência do retratamento, vários sistemas de níquel-titânio (NiTi) têm sido desenvolvidos com a utilização de apenas um instrumento por meio de um movimento reciprocante, levantado novas perspectivas para o preparo biomecânico do canal radicular, bem como, o retratamento. Portanto, este estudo teve por objetivo analisar a produção de desvio e capacidade de limpeza durante retratamento dos canais mesiais de molares inferiores com curvaturas severas (30° e 70°), obturados com BioC Sealer após utilização dos sistemas reciprocantes. Uma amostra de sessenta molares inferiores foi dividida em quatro grupos experimentais, assim distribuídos: G1- X1-Blue (25.06); G2- WaveOne Gold Primary (25.07); G3- Reciproc Blue (25.08); G4- WA1 (25.07). Cada grupo continha 15 molares, totalizando 120 canais mesiais, os quais passaram pela aquisição e processamento das imagens iniciais no Microtomográfo, para que posteriormente, fosse realizado o pareamento dos grupos. Todos os grupos foram instrumentados com o sistema de rotação continua Pro Taper Next. Após instrumentação, foram obturados com cone de guta percha ProTaper Universal, selados e colocados em estufa a 37 °C, 100% de umidade durante 72 horas. Para análise de desvio e remoção da obturação dos canais as amostras foram escaneadas por meio da Microtomografia (MicroCT). Por fim, foi avaliado e medido o desvio apical através da comparação das imagens dos canais obtidas pelas Micro-CT após o retratamento, bem como a remoção do material obturador, para posterior análise estatística. Os resultados quanto a produção de desvio após remoção do material obturador, entre grupos, demonstrou não haver diferença estatisticamente significante tanto para os canais radiculares mesio vestibulares como para os canais mesio linguais (p > 0,05). Na análise intra grupo, não houve diferença em relação aos grupos G1(X1 Blue), G2 (Wave one Gold) e G3 (Reciproc Blue) (p > 0,05), porém o grupo G4 (WA1) apresentou diferença significante, mostrando maior grau de desvio no canal mesio lingual do que no mesio vestibular (p < 0,05). Com relação a remoção do material obturado, na análise entre grupo, para o canal Mesio vestibular, pode-se observar que em todos os grupos houve uma diminuição no sentido cervical para apical, porém, no grupo G4 (WA1) observou-se uma maior remoção tanto no terço médio quanto no apical. No terço cervical a maior remoção do material obturador ocorreu no grupo G2 (Wave one Gold), seguido do G4 (WA1), G3 (Reciproc Blue) e G1(X1 Blue). Para o canal mesio lingual, o grupo G4 (WA1) demonstrou uma maior estabilidade de remoção do material obturador em todos os terços. No terço cervical houve uma maior remoção do material obturador no grupo G2, seguido do G4, G3 e G1, já no terço médio foi no grupo G2, seguido do G1, G4 e G3. No terço apical, o grupo G4 promoveu maior capacidade de remoção de material obturador, seguido de G1, G2 e G3. Para comparação entre médias intragrupos, não houve diferença estatisticamente significante quando se comparou os terços cervical/médio para os Grupos G1 e G4 (tanto no canal Mesio vestibular como no mesio lingual) e terços médio/apical (apenas no canal Mesio lingual), porém, o terço apical foi observado uma maior dificuldade na remoção do material obturador. Conclui-se que a maiorias dos sistemas reciprocantes testados no retratamento promoveram desvio apical, porém o sistema WA1 foi capaz de produzir menos desvio no canal Mesio vestibular. Os sistemas reciprocantes utilizados foram capazes de remove grande parte do material obturador, mas não em sua totalidade, o terço apical foi o que mais dificultou a remoção do material obturador, porém, o sistema WA1 foi o que apresentou maior desempenho neste terço (AU).

Endodontic retreatment is a procedure performed when the previous treatment is unsuccessful and aims to reverse infectious processes, completely removing the shutter material allowing a new cleaning, modeling and reobturation of root canals. With a view to improving success rates and retreatment efficiency, several nickel-titanium (NiTi) systems have been developed with the use of only one instrument through a reciprocal movement, raising new perspectives for biomechanical preparation of the root canal, as well as retreatment. Therefore, this study aimed to analyze the production of deviation and cleaning capacity during retreatment of the mesiaal channels of lower molars with severe curvatures (30° and 70°), obtained with BioC Sealer after using reciprocating systems. A sample of sixty lower molars was divided into four experimental groups, thus distributed: G1- X1-Blue (25.06); G2- WaveOne Gold Primary (25.07); G3- Reciproc Blue (25.08); G4- WA1 (25.07). Each group contained 15 molars, totaling 120 mesiaal channels, which passed through the acquisition and processing of the initial images in the Microtomográfo, so that later, the pairing of the groups was performed. All groups have been instrumented with the continuous Rotation System Pro Taper Next. After instrumentation, they were filled with protaper universal percha gutcone, sealed and placed in a greenhouse at 37 °C, 100% humidity for 72 hours. For analysis of deviation and removal of the filling of the channels, the samples were scanned by microtomography (Micro-CT). Finally, apical deviation was evaluated and measured by comparing the images of the channels obtained by micro-CT after retreatment, as well as removal of the shutter material, for further statistical analysis. The results regarding the production of deviation after removal of the shutter material between groups, showed no statistically significant difference both for vestibular mesium root canals and for lingual mesio channels (p > 0.05). In the intra-group analysis, there was no difference in relation to groups G1(X1 Blue), G2 (Wave one Gold) and G3 (Reciproc Blue) (p > 0.05), but group G4 (WA1) showed a significant difference, showing a higher degree of deviation in the lingual mesium channel than in the vestibular mesium (p < 0.05). Regarding the removal of the obtained material, in the analysis between group, for the vestibular Mesio canal, it can be observed that in all groups there was a decrease in the cervical direction to apical, however, in group G4 (WA1) there was a greater removal in both the middle and apical third. In the cervical third the highest removal of the shutter material occurred in group G2 (Wave one Gold), followed by G4 (WA1), G3 (Reciproc Blue) and G1 (X1 Blue). For the lingual mesio channel, group G4 (WA1) demonstrated greater shutter material removal stability across all thirds. In the cervical third, there was a higher removal of the shutter material in group G2, followed by G4, G3 and G1, already in the middle third it was in group G2, followed by G1, G4 and G3. In the apical third, group G4 promoted higher shutter material removal capacity, followed by G1, G2 and G3. For comparison between intragroup means, there was no statistically significant difference when comparing the cervical/middle thirds for Groups G1 and G4 (both in the vestibular mesio channel and in the lingual mesium) and middle/apical thirds (only in the lingual Mesio canal), however, the apical third was observed a greater difficulty in removing the shutter material. It was concluded that most of the reciprocal systems tested in the retreatment promoted apical deviation, but the WA1 system was able to produce less deviation in the vestibular Mesio canal. The reciprocal systems used were able to remove much of the shutter material, but not in its entirety, the apical third was the one that most difficult to remove the shutter material, however, the WA1 system was the one that performed higher in this third (AU).

Effectiveness of different final irrigation techniques and placement of endodontic sealer into dentinal tubules

Abstract: The aim of this study was to compare two irrigation techniques and four devices for endodontic sealer placement into the dentinal tubules. Ninety-nine single-rooted human teeth were instrumented and allocated to either the control (CO) (n=11) or experimental groups according to the irrigation method: syringe and NaveTip needle (NT) (n=44), and EndoActivator (EA) (n=44). These groups were subdivided according to sealer placement into K-File (KF), lentulo spiral (LS), Easy Clean (EC), and EndoActivator (EA) subgroups. Moreover, the distances of 5 mm and 2 mm from the apex were analyzed. The teeth were obturated with AH Plus and GuttaCore X3. Analyses were performed by scanning electron microscopy associated to cathodoluminescence. The percentage and maximum depth of sealer penetration were measured. Data were evaluated by three-way analysis of variance (ANOVA) and Games-Howell test (p<0.05). EA was superior to NT in percentage of sealer penetration. EC was significantly superior to EA (subgroup) for sealer penetration, and both improved the percentage of sealer penetration when compared to LS. Better sealer penetration was observed at the distance of 5 mm from the apex. Sealer penetration into the dentinal tubules was significantly improved by sonic irrigant activation.

Assessment of rotary and reciprocating movements in root canal filling material removal / Análise dos sistemas rotatórios e reciprocante com diferentes ligas na desobturação em retratamento endodônticos

The aim of this study was to evaluate the effects of preparation, filling removal material, reinstrumentation and reobturation of root canals with different Ni-Ti alloys in endodontic retreatment. Firstly, the selection and pairing of mesial root canals of mandibular molars (n = 45) were performed by computerized micro-tomography (micro-CT). After pairing, the specimens were divided into three groups (n = 15), instrumented with the Mtwo® (up to file 25.06), ProDesign Logic (25.06) and ProDesign R (25.06) systems. After this, the specimens were scanned again for root canal deviation analysis at 2, 4, 6, 8 and 10 mm from the apex and the volume increase of these root canals was evaluated through CTan Then, the root canals were filled with Endofill® with 0.1% rhodamine B and scanned in micro-CT once again. For the retreatment of the specimens, 3 groups were established according to the system used (Reciproc®, Hyflex® and ProDesign Duo Hybrid®). During the retreatment, the specimens were scanned in micro-CT in two more phases, after removal of filling material and after reinstrumentation of the root canals. All the images obtained previous and post-retreatment were compared to evaluate the capacity of removal filling material of each system through the volume of material remaining at 3mm in the apical third. Possible deviation of the root canal was assessed at 2, 4, 6, 8 and 10 mm from the apex. In addition, the times of preparation, removal filling material and reinstrumentation of these files were also evaluated. After the removal filling material and reinstrumentation of the root canals, they were refilled with AH Plus with 0.1% fluorescein. The specimens were sectioned crosswise into 2 mm slices to be analyzed by a confocal laser scanning microscope (CLSM) at 1, 3 and 5 mm from the apex, where the volume of material was evaluated through LAS X 3D and 2D software. The time of preparation, removal filling material and reinstrumentation of the root canals between the different systems was measured by a digital timer. The evaluation of canal volumetric increase and preparation time between Mtwo and ProDesign Logic systems were conducted using Student t-test analysis. Non-parametric Wilcoxon test was used to the intragroup comparison at the 2, 4, 6, 8 and 10 mm levels and non-parametric Mann-Whitney test was used to the comparison between groups in the root canal transportation in all sections of the root canal. The intra-group comparison regarding the presence or absence of root canal deviation after removal of root canal filling material and re-instrumentation was submitted to the parametric T-paired statistical test, since it had a normal distribution. The working time with the different alloys used to removal filling material an reinstrumentation was analyzed through parametric ANOVA e Tukey statistical test. The analysis of the remaining material present in the root canals was performed with nonparametric Kruskal-Wallis and Dunn tests. For the intra-group comparison between the different slices (1, 3 and 5 mm), the data were submitted to nonparametric Friedman and Dunn tests. The level of significance was established at 5% in all analysis. After the initial preparation of the root canals, the ProDesign Logic system proved to be faster than Mtwo system, with statistical difference between them (P <0.05). There was no statistical difference in root canal deviation after initial preparation and after retreatment (P> 0.05). In addition, the groups did not present a significant statistical difference to the volume increase of the root canals after the initial preparation or to the volume of filling material remaining after the retreatment (P> 0.05). The Reciproc system proved to be the fastest system for the removal filling material and reinstrumentation of the root canals (P <0.05). The present study demonstrated that the Prodesign Logic and Mtwo systems presented similar capacity of preparation of mesial root canals. The Reciproc, Hyflex and ProDesign Duo Hybrid systems are similar in the removal of filling material, preserving the original root canal shape in endodontic retreatment. However, Reciproc was the fastest compared to the other groups.(AU)

O presente trabalho teve como objetivo avaliar os efeitos decorrentes do preparo inicial, desobturação, reinstrumentação e reobturação de canais radiculares com diferentes ligas de Ni-Ti em casos de retratamento endodôntico. Primeiramente, foi realizado a seleção e o pareamento da anatomia de canais mesiais de primeiros molares inferiores (n=45) através de micro-tomografia computadorizada (micro-CT). Após o pareamento dos espécimes, os mesmos foram divididos em três grupos (n =15), instrumentados com os sistemas Mtwo® (até a lima 25.06), ProDesign Logic (25.06) e ProDesign R (25.06) sendo escaneados novamente para análise de desvio do canal radicular a 2, 4, 6, 8 e 10 mm, além do aumento de volume desses canais, avaliados através do CTan. Em seguida, os canais radiculares foram obturados com o cimento Endofill® acrescido de 0,1% de rodamina B e escaneados em micro-CT mais uma vez. Para o retratamento dos espécimes, foram estabelecidos 3 grupos, de acordo com o sistema utilizado (Reciproc®, Hyflex® e ProDesign Duo Híbrido®). Durante o retratamento, os espécimes foram escaneados em micro-CT em mais duas etapas, após a desobturação e a após a reinstrumentação dos canais. Todas as imagens obtidas referentes ao pré e pós retratamento foram confrontadas com o intuito de avaliar a capacidade de remoção de material obturador de cada sistema através do volume de material remanescente nos 3 mm apicais, além de avaliar possíveis desvios dos canais a 2, 4, 6, 8 e 10 mm do ápice. Foram avaliados também, o tempo efetivo de preparo, desobturação e de reinstrumentação desses instrumentos. Após a desobturação e reinstrumentação dos canais, os mesmos foram reobturados com cimento AH Plus acrescido de 0,1% de fluoresceína. Os espécimes foram seccionados transversalmente em fatias de 2 mm para serem analisados em microscópio confocal de varredura a laser (MCVL) a 1, 3 e 5 mm do ápice, onde foi avaliado, através do software LAS X 3D e 2D, o volume de material obturador antigo. O tempo de preparo, desobturação e reinstrumentação dos canais entre os diferentes sistemas foi marcado através de um cronômetro digital. A análise do aumento volumétrico e tempo de preparo entre os sistemas Mtwo e ProDesign Logic foi feita através do teste estatístico Student t. Para a análise do desvio do canal radicular após o preparo inicial, o teste não-paramétrico Wilcoxon foi utilizado para a comparação intra-grupos nos níveis a 2, 4, 6, 8 e 10 mm do ápice, enquanto o teste não-paramétrico Mann-Whitney foi utilizado para comparação entre os grupos nos mesmos níveis. Para a análise do desvio do canal radicular após a desobturação e reinstrumentação dos canais, os dados foram submetidos ao teste paramétrico T-pareado. O tempo de desobturação e reinstrumentação com os diferentes sistemas foi analisado através do teste ANOVA e Tukey. Os dados referentes ao remanescente de material obturador foram analisados através dos testes não-paramétrico Kruskal-Wallis e Dunn. Para a comparação intra-grupos entre os diferentes níveis (1, 3 e 5 mm) foram utilizados os testes não-paramétricos Friedman e Dunn. O nível de significância foi estabelecido a 5% em todas as análises. Após o preparo inicial dos canais, o sistema ProDesign Logic demonstrou ser mais rápido que o sistema Mtwo, havendo diferença estatística entre eles (P < 0.05). Não houve diferença estatística quanto ao desvio do canal radicular tanto após o preparo inicial quanto após o retratamento (P > 0.05). Além disso, os grupos também não apresentaram diferença estatística significante quanto ao aumento do volume dos canais após o preparo inicial, nem em relação ao volume de remanescente de material obturador após o retratamento (P > 0.05). O sistema Reciproc demonstrou ser o mais rápido dentre os sistemas quanto à desobturação e reinstrumentação dos canais (P < 0.05). O presente trabalho demonstrou que os sistemas Prodesign Logic and Mtwo apresentaram capacidade similar de preparo dos canais mesiais de molares inferiores. Os sistemas Reciproc, Hyflex e ProDesign Duo Híbrido são parecidos quanto à remoção de material obturador, preservando o formato original do canal em casos de retratamentos entodônticos. Entretanto, Reciproc foi o mais rápido comparado aos outros grupos.(AU)

Evaluation of methods for removal of filling material in endodontic retreatment and assessment of antimicrobial action of solutions used in final irrigation / Avaliação de métodos de desobturação do canal radicular no retratamento endodôntico e avaliação da ação antimicrobiana de soluções utilizadas na irrigação final

When endodontic treatment fails, an alternative could be root canal retreatment. During this procedure, all filling material should be removed to allow a new root canal preparation and new obturation of the root canal system. Bacteria are the main cause of endodontic treatment failure, and persistent infection may be related to microorganism ability to penetrate into dentinal tubules. Therefore, this requires the use of irrigating solutions with antimicrobial action and low toxicity. The aim of this study was to evaluate the performance of instruments made of different alloys in root canal re-instrumentation during endodontic retreatment of lateral incisors with apical curvature, using computed microtomography and assessment of these samples by scanning electron microscopy after irrigant activation. Furthermore, the antimicrobial action of a root canal irrigant containing silver nanoparticles, 2% chlorhexidine and 2.5% sodium hypochlorite was evaluated against Enterococcus faecalis biofilm and dentin infected with this microorganism. Thirty extracted maxillary lateral incisors with apical curvature were selected. The teeth were instrumented, filled and divided into three different groups according to the protocol for removal of filling material: Group 1: re-instrumentation with Reciproc R25 instruments, Mtwo 40 and ProDesign Logic 50.01; Group 2: re-instrumentation with ProDesign R, ProDesign Logic 40 and ProDesign Logic 50.01; Group 3: re-instrumentation with Gates-Glidden drills and manual instruments K-file and Hedstroem files. For filling material removal analysis, the samples were scanned in a microtomograph device SkyScan 1174, for comparison of images taken before and after removing the root canal filling, and in each sample the volume was calculated at four levels (apical 1, apical 2, middle and cervical). These samples were split and analyzed by scanning electron microscopy to visualize filling material residues before and after irrigant activation with an ultrasonic device and with the EasyClean system used in continuous rotary motion. Statistical analyses were performed using Kruskal-Wallis, Friedman, Wilcoxon and Dunn tests. Furthermore, the minimum inhibitory concentration of an irrigating solution containing silver nanoparticles was determined against strains of Enterococcus faecalis, by using the microdilution method. Additionally, the antimicrobial activity of silver nanoparticle solution, 2% chlorhexidine and 2.5% sodium hypochlorite was tested against Enterococcus faecalis biofilm in vitro. For biofilm formation, bovine dentin blocks were placed in 24-well culture plates and Enterococcus faecalis biofilm was developed for 21 days. The dentin blocks were divided into 9 experimental groups of 5 blocks each, according to the irrigating solution used and the time in contact with the irrigant (5, 15 and 30 minutes). The samples were stained with Live/Dead reagent for analysis by confocal laser scanning microscopy (CLSM). Finally, the antimicrobial action of these solutions was tested after dentinal tubules were contaminated with Enterococcus faecalis. Dentin tubes were made from bovine incisors, taken to a centrifuge and infected with Enterococcus faecalis. The dentin tubes were treated with silver nanoparticle solution, 2% chlorhexidine and 2.5% sodium hypochlorite, and analyzed by CLSM to assess the antimicrobial activity of these solutions against bacteria in the dentinal tubules. The results showed that residues of filling material were found after root canal reinstrumentation in all groups. No significant difference was observed in removal of filling material between the reciprocating instruments Reciproc and ProDesign R and between rotary instruments Mtwo 40 and ProDesign Logic 40. The ProDesign Logic 50/.01 instrument significantly improved the removal of filling material compared with the use of Reciproc and ProDesign R instruments. The apical levels presented greater amount of remnant filling material compared with middle and cervical levels. After canal reinstrumentation, the passive ultrasonic irrigation and irrigant agitation with EasyClean significantly improved the removal of residual filling material in all root canal thirds. There was no significant difference between the performance of ultrasonics and EasyClean regarding the removal of residual filling material, as well no significant difference was observed in the removal of these residues when comparing apical, middle and cervical thirds. Regarding the action of the irrigating solutions against Enterococcus faecalis, the minimum inhibitory concentration of silver nanoparticle solution capable of eliminating this microorganism in broth and agar plates was 94 ppm. After the irrigation of Enterococcus faecalis biofilm, the silver nanoparticle solution was significantly less effective in killing bacteria compared with chlorhexidine when used for time of contact of 5 minutes. The sodium hypochlorite solution presented antimicrobial activity significantly higher compared with the silver nanoparticle solution and chlorhexidine. This solution also presented higher ability to dissolve biofilm in all times tested, whereas the silver nanoparticle solution presented higher ability to dissolve biofilm compared with chlorhexidine in times of 5 and 15 minutes. In infected intratubular dentin with Enterococcus faecalis, the sodium hypochlorite solution presented significant higher effectiveness than the silver nanoparticle solutions and chlorhexidine, especially in middle third and deep areas of the root canal. When comparing the antimicrobial activity of these solutions in biofilm and infected intratubular dentin, it was shown that when the silver nanoparticle solution was used for shorter periods of time, it was more effective in intratubular dentin compared with biofilm. On the other hand, with longer time of 30 minutes, the number of viable bacteria was higher in intratubular dentin than in biofilm, which was also observed when using the sodium hypochlorite solution in this time of action. It was concluded that to increase the rate of success in endodontic retreatment, the combination of the use of reciprocating and rotary instruments in the removal of filling material, the agitation of irrigants and the use of antimicrobial agents could be used in an attempt to eliminate bacteria that resisted to endodontic treatment. (AU)

Em casos de insucesso do tratamento endodôntico, uma alternativa seria o retratamento do canal radicular. Durante este procedimento deve haver remoção de todo o material obturador para que seja realizada novo preparo biomecânico e nova obturação do sistema de canais radiculares. Bactérias são o principal fator etiológico em casos de fracasso da terapia endodôntica, e esta infecção persistente pode estar relacionada à capacidade dos microganismos em penetrar nos túbulos dentinários. Por este motivo é necessário o uso de soluções na irrigação do canal radicular com ação antimicrobiana e com boa tolerância tecidual. O objetivo deste trabalho foi avaliar o desempenho dos instrumentos de diferentes ligas metálicas na desobturação do canal radicular durante o retratamento endodôntico de incisivos laterais superiores com curvatura apical, por meio da microtomografia computadorizada e análise destas amostras no microscópio eletrônico de varredura após a ativação de irrigantes. Posteriormente foi avaliada a capacidade antimicrobiana de um irrigante do canal radicular contendo nanopartículas de prata, clorexidina a 2% e hipoclorito de sódio a 2,5% frente ao biofilme de Enterococcus faecalis e à dentina contaminada com este mesmo microrganismo. Foram selecionados trinta incisivos laterais superiores humanos extraídos que apresentavam curvatura apical. Os dentes foram instrumentados, obturados e divididos em três diferentes grupos de acordo com o protocolo de remoção do material obturador do canal radicular: no Grupo 1: a desobturação foi realizada com os instrumentos Reciproc R25, Mtwo 40 e ProDesign Logic 50.01; no Grupo 2: foram utilizados os instrumentos ProDesign R, ProDesign Logic 40 e ProDesign Logic 50.01; e no Grupo 3: a desobturação foi realizada com brocas de Gates-Glidden e instrumentos manuais tipo K e Hedstroem. Para a análise da remoção do material obturador, as amostras foram escaneadas em micrótomogafo SkyScan 1174 para que fossem comparadas as imagens antes e após a desobturação do canal radicular, e em cada amostra este volume foi calculado nos quatro níveis (apical 1, 2, médio e cervical). Estas amostras posteriormente foram clivadas e analisadas no microscópio eletrônico de varredura, para a visualização de resíduos de material obturador antes e após a ativação de irrigantes com o ultrassom e com o sistema EasyClean utilizado em rotação contínua. Para a análise estatística dos resultados foram utilizados os testes de Kruskal-Wallis, Friedman, Wilcoxon e Dunn. Posteriormente, foi determinada a concentração inibitória mínima de uma solução irrigadora do canal contendo nanopartículas de prata frente a cepas de Enterococcus faecalis, através do método de diluição em caldo. Em seguida, foi testada a atividade antimicrobiana das soluções de nanopartículas de prata, da clorexidina a 2% e do hipoclorito de sódio a 2,5% sobre o biofilme de Enterococcus faecalis in vitro. Para isso, foram utilizados blocos de dentina bovina colocados em placas de 24 poços e biofilme de Enterococcus faecalis foi formado durante 21 dias. Os blocos de dentina foram divididos em 9 grupos experimentais com 5 blocos cada um, em função dos irrigantes avaliados e do tempo de exposição à solução irrigadora (5, 10 e 15 minutos). As amostras foram coradas com corante Live/Dead para posterior análise no microscópio confocal de varredura a laser (MCVL). Por fim, foi testada a atividade antimicrobiana destas soluções irrigadoras após a contaminação de túbulos dentinários com Enterococcus faecalis. Foram confeccionados tubos de dentina a partir de incisivos bovinos que foram levados à centrífuga e contaminados com Enterococcus faecalis. Os tubos de dentina receberam tratamento com a solução de nanopartículas de prata, com clorexidina a 2% e com hipoclorito de sódio a 2,5%, e foram analisados no MCVL para avaliar a atividade antimicrobiana das soluções sobre bactérias presentes nos túbulos dentinários. Os resultados demonstraram que resíduos de material obturador foram encontrados após a desobturação do canal em todos os grupos. Não houve diferença significante na remoção de material obturador entre os instrumentos reciprocantes Reciproc e ProDesign R e entre os instrumentos rotatórios Mtwo 40 e ProDesign Logic 40. O instrumento ProDesign Logic 50/.01 melhorou significantemente a remoção de material obturador comparado com o uso dos instrumentos Reciproc e ProDesign R. Os níveis apicais apresentaram uma maior quantidade de material obturador remanescente comparados com os níveis médio e cervical. Após a desobturação do canal radicular, a irrigação ultrassônica passiva e agitação dos irrigantes com o EasyClean melhoraram significantemente a remoção de resíduos de material obturador em todos os terços do canal radicular. Não houve diferença significante no desempenho do ultrassom e do EasyClean em relação à remoção de resíduos de material obturador, assim como não foi observada diferença significante na remoção destes resíduos quando comparados terços apical, médio e cervical. No que diz respeito à ação das soluções irrigadoras sobre o Enterococcus faecalis, a concentração inibitória mínima da solução de nanopartículas de prata capaz de eliminar este microrganimo em meio de cultura e ágar foi de 94 ppm. Após a irrigação no biofilme de Enterococcus faecalis, a solução de nanopartículas de prata foi significantemente menos efetiva em matar bactérias comparada com a clorexidina quando utilizadas pelo tempo de 5 minutos. A solução de hipoclorito de sódio apresentou atividade antimicrobiana significantemente maior comparada com as soluções de nanopartículas de prata e clorexidina. Essa solução ainda apresentou maior capacidade de dissolução do biofilme em todos os tempos testados, enquanto que a solução de nanopartículas de prata apresentou maior capacidade de dissolver o biofilme comparada à clorexidina nos tempos de 5 e 15 minutos. Na dentina intratubular infectada com Enterococcus faecalis, a solução de hipoclorito de sódio apresentou efetividade significantemente maior que as soluções de nanopartículas de prata e clorexidina, principalmente no terço médio e na região profunda do canal radicular. Quando comparada a atividade antimicrobiana destas soluções no biofilme e na dentina intratubular infectada, verificou-se que quando a solução de nanopartículas de prata foi utilizada por um tempo mais curto, foi mais efetiva na dentina intratubular comparada com o biofilme. De maneira contrária, com tempo maior de 30 minutos, o número e bactérias viáveis foi maior na dentina intratubular do que no biofilme, o que ocorreu também com a solução de hipoclorito de sódio neste tempo de ação. Conclui-se que para se aumentar a chance de sucesso em tratamentos retratamentos endodônticos, a combinação do uso de instrumentos reciprocantes e rotatórios na desobturação do canal, agitação de irrigantes e uso de agentes com capacidade antimicrobiana podem ser utilizados na tentativa de se eliminar bactérias resistente ao tratamento endodôntico. (AU)

Obturación tridimensional: un factor clave en el pronóstico del tratamiento endodóncico: caso clínico / Tri-dimensional filling: a key factor in the outcome of endodontic treatment: case report

La calidad de la obturación del conducto radicular está considerada en la actualidad como un factor de gran influencia en el resultado del tratamiento endodóncico (TE). La tomografía computerizada de haz cónico (CBCT) puede ser utilizada para confirmar un diagnóstico sobre la morfología del conducto radicular, y está indicada en la evaluación de complicaciones post-tratamiento, cuando el examen radiográfico convencional no aporta suficiente información. Estudios recientes realizados con micro-CT muestran variaciones anatómicas que pueden estar implicadas en el fracaso del TE. Los clínicos deben tener en cuenta las variaciones anatómicas de los dientes y las ventajas de utilizar el CBCT en situaciones específicas. Este caso clínico pretende resaltar la importancia de una obturación tridimensional en el éxito del TE

The quality of the root canal filling is currently recognized as a factor that influences the outcome of the endodontic treatment (ET). Cone beam computerized tomography (CBCT) can be used to confirm a diagnosis of root canal morphology and is indicated in the evaluation of post-treatment complications, when conventional radiographic examination does not provide sufficient information. Recent studies with micro-CT present anatomic variations which can be implicated in the ET failure. Clinicians should be aware of the teeth’s morphological variations and of the advantages of using CBCT in specific situations. This case report aims to highlight the importance of a tri-dimentional filling in the success of the ET

Análisis morfométrico de conos de gutapercha Mtwo / Morphometric analysis of Mtwo gutta-percha cones

Objetivo: Evaluar cuantitativamente el calibre y la conicidad de los conos de gutapercha Mtwo (VDW, Munich, Alemania). Materiales y métodos: se seleccionaron al azar 50 conos de gutapercha marca Mtwo (VDW, Munich, Alemania) entre 300, provenientes de 5 cajas de conos surtidos #25 .06, #30 .05, #35 .04, #40 .04 y #25 .07. Fueron descartados aquellos que visualmente tenían algún defecto. Los elegidos se separaron en grupos de 10, según el número. Se midió cada cono en el vértice y a 1 mm, 2 mm, 3 mm, 4 mm y 5 mm, con un especímetro centesimal modelo 7301 (Mitutoyo, Japón). Se realizaron 300 determinaciones, que fueron efectuadas por dos operadores. Cuando hubo diferencias, se repitieron las mediciones hasta hallar coincidencia. Los datos fueron registrados en una planilla de Excel (Microsoft Corporation, Estados Unidos) diseñada al efecto. El análisis estadístico se llevó a cabo con prueba de hipótesis de dos colas, contrastando la media con el valor teórico. Resultados: se hallaron diferencias estadísticamente significativas para los conos #25 .06, en la determinación a 2 mm. En cuanto al resto de las mediciones, no hubo diferencias significativas. Conclusión: de acuerdo a los resultados obtenidos sobre la muestra analizada, en general los conos de gutapercha Mtwo respetan las espcificaciones ISO de fabricación.

Retratamiento endodóntico de una reabsorción radicular interna asociada a un conducto lateral / Endodontic retreatment of an internal root resorption associated with a lateral canal

La reabsorción radicular interna (RRI) es una patología que se caracteriza por la destrucción de las paredes del conducto radicular generando una forma de "ampolla". Está asociada a una afección pulpar, por el efecto de causas físicas, químicas y/o bacterianas que estimulan la actividad clástica. El tratamiento endodóntico se presenta como la solución óptima para detener dicha reabsorción. A continuación se muestra un caso clínico de retratamiento ortógrado, donde la RRI está asociada a la presencia de un conducto lateral, concomitante con una radiolucidez perirradicular

Internal root re-absorption (IRR) is a pathology characterized by the destruction of the root canal walls generating a shape of "blister". It is associated with the invasion of the pulp of the tooth, due to the effect of physical, chemical and / or bacterial causes which stimulate clastic activity. Endodontic treatment is presented as the best solution to stop this re-absorption. A clinical case of retrograde root canal re-treatment is reported, where the IRR is associated with the presence of a lateral canal with concomitant periradicular radiolucency