The effect of ultrasonic vibration protocols for cast post removal on the incidence of root dentin defects.

PURPOSE: To investigate the effects of two ultrasonic vibration protocols for cast post removal (single or double ultrasound units) on the development of defects in root dentin. METHODS: Sixty bovine incisors were selected. Fifteen roots were left unprepared (control). Forty-five roots were instrumented and filled. A 10-mm post space was prepared using #1-4 Largo drills. Fifteen teeth were prepared for post space and received no further procedure. Thirty roots had cast posts cemented and were submitted to ultrasonic vibration protocols for removal. The time necessary to remove each post was recorded. Roots were sectioned 3, 6, 9, and 12 mm from the coronal portion and viewed through a 25× magnification in a stereomicroscope. The presence of root fractures, partial cracks, and craze lines was registered. Chi-square and Fisher's exact tests were performed to compare the incidence of dentin defects. The Kruskal-Wallis test was performed to explore the difference between the time needed for post removal. The significance level was set at P = 0.05. RESULTS: Root defects were observed in all experimental groups. There were no statistical differences comparing previous root canal treatment and post removal steps, either with 1 or 2 ultrasonic units, in the formation of defects (P = 0.544) or fractures (P = 0.679). CONCLUSION: Ultrasonic vibration protocols for removing cast posts did not increase the number of dentin defects compared to root canal preparation and obturation and post space preparation steps.

Guided Access Cavity Preparation Using a New Simplified Digital Workflow.

INTRODUCTION: This study evaluated the precision of a simplified workflow using only preoperative cone-beam computed tomographic (CBCT) scans to gain guided access to root canals of extracted mandibular molars. A workflow using CBCT scanning associated with 3-dimensional oral scanning was used as a reference for comparison. The influence of the presence of coronal restoration in the simplified workflow was also evaluated. METHODS: Forty-five mandibular molars were randomized into 3 groups: a control group in which digital planning was performed with CBCT and oral scanning and 2 experimental groups in which digital planning was performed only with CBCT examination. In experimental group 1, teeth had no coronal restorations, whereas in group 2 teeth presented with coronal composite restorations. After digital planning, the teeth were accessed using the guides, and a new CBCT scan was made to overlap the pre- and postoperative examinations. Precision was measured by calculating the deviation between the planned and prepared cavities in millimeters and angle. Data were compared using 1-way analysis of variance (P < .05). RESULTS: All root canals were accessible after access preparation in all tested groups. Deviations of the planned and prepared access cavities were low, with a mean value of 0.55, 0.58, and 0.47 mm and 1.98°, 2.45°, and 1.43° for the control group, group 1, and group 2, respectively. No significant differences in millimeters or angle were observed among the 3 tested groups (P > .05). CONCLUSIONS: The simplified digital workflow using only CBCT examination allowed a high level of precision in obtaining access in extracted molars with and without coronal restoration, presenting similar results compared with the digital workflow using CBCT and 3-dimensional oral scanning.

Digital Planning on Guided Endodontics Technology.

The aim of this review is to discuss the digital planning and the use of guided technology in Endodontics. The complexity of the root canals anatomy and the challenges in the microorganism's control represent risk factors for failure after the infected root canal's treatment. Scientific improvements associated with technological advances have enabled better predictability of therapeutic procedures results. The development of efficient and modern devices provided safer root canal treatments, with shorter clinical visits and greater patient comfort. Digital endodontics incorporated different tools and developed its own, advancing even further in resolving complex cases. The faithful copy of the internal anatomy provided by the advancement of CBCT devices and software's, associated with the digital resources of 3D planning and printing, enabled the advent of guided endodontics. This technique is used at different stages of endodontic treatment, with specific indications and greater result predictability. Therefore, this study critically reviewed the potential clinical application of this guided access technique, and the operative steps for its safe performance in managing complex endodontic cases. The main indications are accessing calcified root canals, performing endodontic surgeries in difficult access areas, removing fiberglass posts, and accessing teeth with developmental anomalies. In summary, guided endodontics has been a precise strategy, effective, safe, and clinically applicable. This procedure represents incorporating technological resources and digital planning in the Endodontist clinical practice, increasing predictability to complex cases.

Digital Planning on Guided Endodontics Technology

Abstract The aim of this review is to discuss the digital planning and the use of guided technology in Endodontics. The complexity of the root canals anatomy and the challenges in the microorganism's control represent risk factors for failure after the infected root canal's treatment. Scientific improvements associated with technological advances have enabled better predictability of therapeutic procedures results. The development of efficient and modern devices provided safer root canal treatments, with shorter clinical visits and greater patient comfort. Digital endodontics incorporated different tools and developed its own, advancing even further in resolving complex cases. The faithful copy of the internal anatomy provided by the advancement of CBCT devices and software's, associated with the digital resources of 3D planning and printing, enabled the advent of guided endodontics. This technique is used at different stages of endodontic treatment, with specific indications and greater result predictability. Therefore, this study critically reviewed the potential clinical application of this guided access technique, and the operative steps for its safe performance in managing complex endodontic cases. The main indications are accessing calcified root canals, performing endodontic surgeries in difficult access areas, removing fiberglass posts, and accessing teeth with developmental anomalies. In summary, guided endodontics has been a precise strategy, effective, safe, and clinically applicable. This procedure represents incorporating technological resources and digital planning in the Endodontist clinical practice, increasing predictability to complex cases.

Resumo O objetivo desta revisão é discutir o planejamento digital e o uso da tecnologia guiada em Endodontia. A complexidade e variabilidade da anatomia dos canais radiculares, em conjunto com o desafio no processo de sanificação e controle de micro-organismos representam fatores de risco ao fracasso após o tratamento dos canais radiculares infectados. O aprimoramento técnico-científico e os avanços tecnológicos tem possibilitado uma melhor previsibilidade de resultados nos procedimentos terapêuticos. O desenvolvimento de ferramentas de trabalho eficientes e modernas proporcionou tratamentos endodônticos seguros, com menor tempo clínico operacional e maior conforto ao paciente. A endodontia digital incorporou diferentes ferramentas e desenvolveu suas próprias, avançando ainda mais na resolução de casos complexos. A cópia fiel da anatomia interna proporcionada pelo avanço dos aparelhos e softwares de TCFC, associada aos recursos digitais de planejamento e impressão 3D possibilitaram o surgimento da endodontia guiada. Esta técnica é utilizada em diferentes etapas do tratamento endodôntico, com indicações específicas e maior previsibilidade de resultados. Este estudo revisou criticamente o potencial de aplicação clínica da técnica de acesso guiado, e os passos operatórios para sua realização de forma segura no manejo de casos endodônticos complexos. As principais indicações da Endodontia Guiada incluem o acesso a canais radiculares calcificados; as cirurgias parendodônticas em áreas de difícil acesso; a remoção de pinos de fibra de vidro; e o acesso a dentes com anomalias de desenvolvimento. Em síntese, a endodontia guiada é uma técnica precisa, eficaz e de fácil aplicação clínica. Esta técnica representa a incorporação dos recursos tecnológicos e planejamentos digitais do Endodontista, dando maior previsibilidade aos casos em que é aplicada na prática clínica.

Guided endodontics: The impact of new technologies on complex case solution.

Discuss the impact of new diagnostic and planning technologies on the resolution of a clinical case of an upper central incisor with lateral perforation, root canal calcification and apical periodontitis. A 44-year-old woman sought treatment because of a colour change in an anterior tooth. The tooth had already been endodontically accessed, and she reported that two different clinicians had failed to locate the root canal. A Cone Beam Computed Tomography scan showed excessive wear and root perforation in the middle third, as well as pulp canal obliteration in the apical third. The perforation was treated using a biomaterial, and the root canal was located using guided endodontics. This treatment protocol was used to access, prepare, medicate with calcium hydroxide for 21 days and fill the root canal. Treatment results were satisfactory at 6-month follow-up.

Potential of a New Cone-Beam CT Software for Blooming Artifact Reduction.

This study evaluated the dimensions of intraradicular posts using a new cone beam CT (CBCT) software, and verified the potential of blooming artifact reduction. Sixty-three single-rooted human teeth were shaped, obturated, prepared for intracanal post placement and distributed into three groups: G1: anatomically customized prefabricated glass fiber posts; G2: low-fusion alloy posts; G3: gold alloy posts. After post fabrication and luting with RelyX U200®, specimens were sectioned axially at 9 mm from the root apex, and markings were made on the root surfaces (X-, Y- and Z-axes). The dimensions of the original posts (control group) were measured using a digital micrometer. CBCT scans of the teeth were obtained using a PreXion 3D Elite® scanner. Posts were measured on CBCT scans using DICOM files and the e-Vol DX software. A specific filter, Blooming Artefact Reduction (BAR), was developed to analyze intracanal posts. Statistical data were evaluated using the Van de Waerden nonparametric analysis of variance and, after that, normalized data were analyzed using the Tukey test. The level of significance was set at α = 5%. The measures of the anatomical prefabricated, low-fusion alloy and gold alloy intracanal posts obtained using the e-Vol DX CBCT software and a micrometer were not significantly different (p>0.05). The use of the BAR filter of the e-Vol DX software application did not induce any dimensional differences on CBCT scans of intracanal posts when compared with measurements made with a micrometer on original posts. The use of the BAR filter eliminated blooming artifacts.

Potential of a new cone-beam ct software for blooming artifact reduction

Abstract This study evaluated the dimensions of intraradicular posts using a new cone beam CT (CBCT) software, and verified the potential of blooming artifact reduction. Sixty-three single-rooted human teeth were shaped, obturated, prepared for intracanal post placement and distributed into three groups: G1: anatomically customized prefabricated glass fiber posts; G2: low-fusion alloy posts; G3: gold alloy posts. After post fabrication and luting with RelyX U200®, specimens were sectioned axially at 9 mm from the root apex, and markings were made on the root surfaces (X-, Y- and Z-axes). The dimensions of the original posts (control group) were measured using a digital micrometer. CBCT scans of the teeth were obtained using a PreXion 3D Elite® scanner. Posts were measured on CBCT scans using DICOM files and the e-Vol DX software. A specific filter, Blooming Artefact Reduction (BAR), was developed to analyze intracanal posts. Statistical data were evaluated using the Van de Waerden nonparametric analysis of variance and, after that, normalized data were analyzed using the Tukey test. The level of significance was set at α = 5%. The measures of the anatomical prefabricated, low-fusion alloy and gold alloy intracanal posts obtained using the e-Vol DX CBCT software and a micrometer were not significantly different (p>0.05). The use of the BAR filter of the e-Vol DX software application did not induce any dimensional differences on CBCT scans of intracanal posts when compared with measurements made with a micrometer on original posts. The use of the BAR filter eliminated blooming artifacts.

Resumo Este estudo avaliou as dimensões de pinos intrarradiculares usando um novo software de tomografia computadorizada de feixe cônico (TCFC) e um micrômetro digital, e verificou o potencial da redução do artefato de contraste do branco. Sessenta e três dentes humanos unirradiculares foram modelados, obturados, preparados para colocação de pinos e distribuídos em três grupos: G1: pino de fibra de vidro pré-fabricado anatômico; G2: pino metálico de liga de baixa fusão; G3: pino metálico de liga de ouro. Após a confecção e cimentação dos pinos com RelyX U200®, os espécimes foram cortados no sentido axial a 9 mm do ápice radicular, sendo efetuadas marcações em suas superfícies radiculares (eixos X, Y e Z) para orientação das medidas e sincronizações das imagens. Foi utilizado um micrômetro digital para a mensuração das dimensões dos pinos originais (grupo controle) associado ao microscópio operatório. Posteriormente, as imagens em TCFC foram obtidas usando o PreXion 3D Elite®. Para a mensuração dos pinos nas imagens de TCFC utilizou-se o arquivo DICOM e a ferramenta de medida do software e-Vol DX, configurada para medidas milesimais, com o filtro BAR (Blooming Artifact Reduction). Os dados estatísticos foram avaliados com a análise de variância não-paramétrica de Van der Waerden, seguida pelo Teste de Tukey aplicado aos dados normalizados. O nível de significância foi de α = 5%. Os resultados mostraram que as medidas dos diâmetros dos pinos intrarradiculares (fibra de vidro anatômico, metálico liga de baixa fusão, e em liga de ouro) usando o software e-Vol DX e o micrômetro não mostram diferenças significativas entre si. O uso do filtro BAR do software e-Vol DX não induziu diferenças dimensionais nas imagens de TCFC dos pinos quando comparadas às medidas realizadas com o micrômetro sobre os pinos originais. O uso do filtro BAR eliminou artefatos de contraste do branco.

Guided Endodontics: Volume of Dental Tissue Removed by Guided Access Cavity Preparation-An Ex Vivo Study.

INTRODUCTION: Guided endodontics emerged as an alternative method capable of providing greater precision and accuracy to endodontic treatments. The aim of the present study was to compare the volume of dental tissue removed after guided endodontic access (GEA) and conventional endodontic access (CEA) to mandibular incisors and upper molars. METHODS: Twenty extracted human mandibular incisors and upper molars were selected and submitted to cone-beam computed tomographic (CBCT) examination. They were divided into 2 groups, G1 (mandibular incisors) and G2 (maxillary molars), and subdivided into G1a (CEA), G1b (GEA), G2a (CEA), and G2b (GEA). The Digital Imaging and Communications in Medicine files obtained by examining the CBCT scans were transferred to InVesalius software (Renato Archer Information Technology Center, Campinas, SP, Brazil) to calculate the initial volume of each tooth. G1b and G2b teeth were scanned with a device to plan and print the guides. After gaining endodontic access, new CBCT examinations were performed to calculate the final volume of each sample unit. The Student t test for independent samples compared the volumes among the groups. RESULTS: G1 group had an average volume reduction of 31.667 mm3 (10.62%) using CEA and 26.523 mm3 (10.65%) using GEA with no significant difference among the groups (P = .960). There was an average volume reduction of 62.526 mm3 (5.86%) in the G2 group using CEA and 45.677 mm3 (4.11%) using GEA with a significant difference among the groups (P = .004). CONCLUSIONS: GEA preserved a greater volume of dental tissue in extracted upper human molars than CEA; however, there was no significant difference between CEA and GEA in the volume of dental tissue removed from mandibular incisors.

Dynamic torque analysis of rotary and reciprocating instruments during root canal instrumentation in simulated canals by an endodontist or a general dentist.

BACKGROUND: Excessive torque is associated with engine-driven file fracture. AIMS: The aim of this study to evaluate the real-time torque of rotary and reciprocating instruments, working time, and the occurrence of procedural errors during root canal preparation of simulated canals by an endodontist and a general dentist. METHODS: Thirty-six commercially available simulated "J-shaped" root canals in resin blocks were used. Instrumentation was performed using WaveOne, WaveOne Gold, ProTaper Next, Reciproc, Reciproc Blue, and Mtwo. The real-time torque analysis and the number of times the maximum torque applied to the instrument were evaluated. Images were obtained to assess the occurrence of procedural errors, and working time was recorded. STATISTICAL ANALYSIS: The one-way analysis of variance with a Bonferroni post hoc test, Mann Whitney test and the t-test was used for statistical analysis (P < 0.05). RESULTS: Reciprocating instruments showed lower values in the number of times that reached maximum torque and percentage time in the area of critical torque, with significant differences compared to rotary instruments (P < 0.05). Operators influenced torque values only with rotary motion instruments. There was no significant difference in mean working time between the operators or instruments. No fracture of instruments or canal transportation occurred. CONCLUSIONS: Rotary instruments were associated with higher peaks in real-time torque variation during the preparation of simulated root canals.

Bone Marrow Transplantation in Patients With Acute Leukemia In Cuba: Results From the Last 30 Years and New Opportunities Through International Collaboration.

Blood and marrow transplantation (BMT) has been performed in Cuba for over 30 years with limited resources and without international relationships. Researchers from University of Illinois at Chicago and Hermanos Ameijeiras Hospital (HAH) in Havana collaborated on retrospectively analyzing 101 consecutive patients with adult acute leukemia who received BMT at HAH from June 1986 to January 2016. Of these, 82 had acute myeloid leukemia (AML) and 19 had acute lymphoblastic leukemia (ALL). BMT eligibility criteria included prior morphologic complete remission, no severe comorbidities, and age between 16 and 60 years. Patients with an HLA-matched donor received an allogeneic BMT, whereas the others received an autologous BMT. All patients received fresh stem cells from marrow (80%) or mobilized peripheral blood (19%). Of 82 patients with AML, 35 received an allogeneic (AML-allo) and 47 an autologous (AML-auto) BMT. Both groups had comparable median age (37 years) and follow-up of survivors. Overall survival (OS) was 34% in AML-allo and 38% in AML-auto. The transplant-related mortality rate was 40% in AML-allo and 17% in AML-auto, whereas the relapse-related mortality rates were 25% and 40%, respectively. Of the 19 patients with ALL, six received an allogeneic transplant. Of these, transplant-related mortality occurred in one patient and three died after disease relapse (OS, 33%). Of 13 patients who received autologous transplants, transplant-related mortality occurred in three and six died after disease relapse (OS, 31%). To our knowledge, this is the first scientific report on BMT performed in patients with acute leukemia in Cuba. The collaboration between University of Illinois at Chicago and HAH will further develop capacity building in research and implementation of new diagnostic and therapeutic strategies in Cuba.

Demetallization of Enterococcus faecalis biofilm: a preliminary study.

Objectives To determine the concentration of calcium, iron, manganese and zinc ions after the application of chelator to Enterococcus faecalis biofilms. Material and Methods Fifty bovine maxillary central incisors were prepared and inoculated with E. faecalis for 60 days. The following were used as irrigation solutions: 17% EDTA (pH 3, 7 and 10), 2.5% sodium hypochlorite (NaOCl) combined with 17% EDTA (pH 3, 7 and 10), distilled water (pH 3, 7 and 10), and 2.5% NaOCl. Each solution was kept in the root canal for five minutes. Fifteen uncontaminated root canals were irrigated with 17% EDTA (pH 3, 7 and 10). Six teeth were used as bacterial control. The number of calcium, iron, manganese and zinc ions was determined using flame atomic absorption spectrometry. Mean ± standard deviation (SD) values were used for descriptive statistics. Results Calcium chelation using 17% EDTA at pH 7 was higher than at pH 3 and 10, regardless of whether bacterial biofilm was present. The highest concentration of iron occurred at pH 3 in the presence of bacterial biofilm. The highest concentration of manganese found was 2.5% NaOCl and 17% EDTA at pH 7 in the presence of bacterial biofilm. Zinc levels were not detectable. Conclusions The pH of chelating agents affected the removal of calcium, iron, and manganese ions. The concentration of iron ions in root canals with bacterial biofilm was higher after the use of 17% EDTA at pH 3 than after the use of the other solutions at all pH levels.

Demetallization of Enterococcus faecalis biofilm: a preliminary study

Abstract Objectives To determine the concentration of calcium, iron, manganese and zinc ions after the application of chelator to Enterococcus faecalis biofilms. Material and Methods Fifty bovine maxillary central incisors were prepared and inoculated with E. faecalis for 60 days. The following were used as irrigation solutions: 17% EDTA (pH 3, 7 and 10), 2.5% sodium hypochlorite (NaOCl) combined with 17% EDTA (pH 3, 7 and 10), distilled water (pH 3, 7 and 10), and 2.5% NaOCl. Each solution was kept in the root canal for five minutes. Fifteen uncontaminated root canals were irrigated with 17% EDTA (pH 3, 7 and 10). Six teeth were used as bacterial control. The number of calcium, iron, manganese and zinc ions was determined using flame atomic absorption spectrometry. Mean ± standard deviation (SD) values were used for descriptive statistics. Results Calcium chelation using 17% EDTA at pH 7 was higher than at pH 3 and 10, regardless of whether bacterial biofilm was present. The highest concentration of iron occurred at pH 3 in the presence of bacterial biofilm. The highest concentration of manganese found was 2.5% NaOCl and 17% EDTA at pH 7 in the presence of bacterial biofilm. Zinc levels were not detectable. Conclusions The pH of chelating agents affected the removal of calcium, iron, and manganese ions. The concentration of iron ions in root canals with bacterial biofilm was higher after the use of 17% EDTA at pH 3 than after the use of the other solutions at all pH levels.

Presence of Metallic Microfragments on Dentinal Walls and Instrument Defects following Root Canal Preparation.

AIM: To determine the presence of metallic microfragments and their elemental composition in the dentinal walls of root canals following preparation using different endodontic instruments and to assess the active cutting edges of instruments with regard to structural defects. MATERIALS AND METHODS: A total of 108 molar teeth were selected and prepared using different endodontic instruments. Teeth were randomly divided into nine groups of 12 teeth each, according to the instruments employed: Manual systems -K-FlexoFile, K-File, and Hedstroem; rotary systems - ProTaper Next, Mtwo, BioRaCe; and reciprocating systems - Reciproc, Unicone, and WaveOne. Both root canals and instruments were assessed using scanning electron microscopy, and the elemental composition of metallic microfragments was determined using energy-dispersive X-ray spectroscopy. RESULTS: Metallic microfragments were found in the groups prepared with both manual and reciprocating instruments, with no statistically significant differences between groups, thirds, or presence of metallic microfragments (p ≥ 0.05). Moreover, all groups presented structural defects in both new and used instruments; however, rotary instruments (ProTaper Next, Mtwo 702, BioRaCe) were the ones with the lowest number of defects, at statistically significant differences in comparison with other instruments (p < 0.05). CONCLUSION: The presence of metallic microfragments on dentinal walls following root canal preparation was associated with manual and reciprocating instrumentation. Furthermore, rotary instruments were the ones with the lowest number of defects. Considering the outcomes measured in this study, rotary instruments performed better than the other two groups, as they were associated with the lowest number of metallic microfragments and structural defects. CLINICAL SIGNIFICANCE: During root canal preparation, operative procedures may induce changes to the root canal shape, as well as the release of metallic fragments resulting from the action of instruments on dentinal walls. Therefore, it is important to determine, among the different techniques used for this purpose, which ones are least susceptible to this occurrence.

Stem Cell Marker Expression in Persistent Apical Periodontitis.

INTRODUCTION: This study evaluated the expression of CD90 (mesenchymal stem cell) and Sox2 (progenitor stem cell) markers in persistent apical periodontitis (PAP) (n = 16) and primary periapical lesions (PPLs) (n = 10). METHODS: All samples were classified histologically according to the intensity of inflammatory cell infiltrate in the periapical lesion. Immunohistochemistry was used to detect CD90 and Sox2 in PAP and PPLs. The Spearman correlation coefficient and the Mann-Whitney U test were used to analyze data at the 5% significance level. RESULTS: CD90 expression was found in mesenchymal cells and vascular endothelial cells of 68.5% of all cases of PAP. There was no correlation between CD90 expression and histopathological diagnosis (P = .053) or inflammatory cell infiltrate intensity (P = .112). CD90 staining was predominantly found in the vascular endothelial cells of 30% (n = 3) of PPLs. CD90 expression was significantly higher in PAP than in PPLs (Mann-Whitney U test, P < .05). Sox2 expression was found in all cases of PAP. Eventually, all mesenchymal and chronic inflammatory cells exhibited Sox2 expression. There was no correlation between Sox2 expression and histopathological diagnoses (P = .749), inflammatory cell infiltrate intensity (P = .510), or acute or chronic inflammatory cell infiltrate (P = .256). Sox2 expression was found in 100% of PPLs. There was no difference in Sox2 expression between PAP and PPLs (P = .477). CONCLUSIONS: Mesenchymal stem cells may contribute to the immunosuppressive environment in PAP. Additionally, distinct stem cell sources may be associated with the chronic nature of PAP as well as with the development of PPLs.

Caracterização da imagem do canal radicular preenchido com hidróxido de cálcio na tomografia computadorizada de feixe cônico / Characterization of the image of root canal filled with calcium hydroxide in cone beam computed tomography

Objetivo: Caracterizar a imagem do canal radicular preenchido com hidróxido de cálcio na tomografia computadorizada de feixe cônico (TCFC). Metodologia: Vinte e sete canais radiculares foram sanificados e preparados até a lima K-File de no 50, 1 mm aquém do forame apical. A seguir, os dentes foram divididos aleatoriamente em três grupos: grupo 1- canais radiculares preenchidos com pasta de hidróxido de cálcio associado à solução fisiológica (n=9); grupo 2- canais radiculares obturados com Endo-Fill® e cones de guta-percha (n=9); grupo 3- canais radiculares sem preenchimento (n=9). Após o preparo e preenchimento dos canais radiculares, imagens de TCFC foram adquiridas e os espécimes secionados nos planos axial, sagital ou coronal usando brocas Endo Z em alta rotação. As medidas das imagens dos canais nas seções transversais dos espécimes foram obtidas por meio de um paquímetro digital, e nas imagens da TCFC foram obtidas utilizando o programa do fabricante do tomógrafo. As diferenças entre as medidas dos espécimes e das imagens da TCFC foram determinadas em diferentes planos. Resultados: As imagens dos espécimes do grupo contendo pasta de hidróxido de cálcio apresentaram densidades similares às observadas nas dentinas, o que não permitiu a mensuração com vistas a determinar alteração de dimensão. O grupo preenchido com Endo-Fill® e guta-percha apresentou um aumento de 37,40% a 47,40% nas dimensões das imagens radiopacas. Conclusão: Imagens de tomografia computadorizada de feixe cônico em canais radiculares preenchidos com pastas de hidróxido de cálcio apresentaram densidades similares às das dentinas, as quais não demonstraram alterações dimensionais.

Aim: To characterize the image of the root canal filled in with calcium hydroxide in cone beam computed tomography (CBCT). Methodology: Twenty-seven root canals were prepared up to K-file #50, 1 mm below the foramen. After, the teeth were randomly divided into three groups: group 1- root canals filled in with calcium hydroxide paste associated with saline (n=9); group 2- root canals filled with Endo-Fill ® and gutta-percha (n=9); group 3- root canals without filling (n=9). After root canals preparation and filling, CBCT images were acquired and the specimens sectioned in axial, sagittal or coronal plans using Endo Z drills at high speed. Root canals measurements from cross sections of specimens were obtained using a digital caliper, and from CBCT images using the manufacturer?s software. The differences between the sizes of specimens and CBCT images were determined at different plans. Results: Specimens images of the group containing calcium hydroxide paste had densities similar to those ones observed in dentin, which did not allow the measurement in order to determine size change. The group filled in with Endo-Fill ® and gutta-percha showed an increase of 37.40% to 47.40% in the dimensions of radiopaque images. Conclusion: Images of cone beam computed tomography in root canals filled in with calcium hydroxide pastes showed densities similar to those of dentin, which did not determine dimensional changes. Care should be taken that these images are not confused with calcified canals.

Avaliação qualitativa do preparo de canais radiculares realizado "in vitro'' com instrumentos rotatórios de níquel-titânio RaCe e K3 / Qualitative evaluation of root canal preparations performed in vitro with rotary nickel-titanium instruments K3 and RaCe

O objetivo do presente estudo foi analisar a conicidade e regularidade dos canais radiculares preparados com instrumentos rotatórios de níquel-titânio Race® e K3®, utilizando contra ângulo redutor Dentfex®. O experimento envolveu canais me-siais de trinta molares humanos, superiores e inferiores, sendo aleatoriamente distribuídos em dois grupos de quinze, de acordo com os dois tipos de instrumentos rotatórios: RaCe® e K3®. A partir de então, realizou-se a moldagem dos canais radiculares, para em seguida submeter os dentes a desmineralização em ácido clorídrico a 35%, obtendo dessa forma o molde dos mesmos. Esses moldes foram analisados, onde se verifcou a conicidade e regularidade dos canais radiculares preparados. Os dados foram tabulados e submetidos à análise estatística por meio dos testes de Mann-Whitney e Qui-quadrado. Os resultados obtidos indicam a predominância de formas regulares cônicas, em todos os terços (cervical, médio, apical), nos sentidos mésio vestibular e mésio lingual e palatino dos canais preparados com os instrumentos Race® e K3®, mas houve diferença estatisticamente signifcante entre o número de ocorrência da forma irregular cilíndrica nos moldes dos canais mésio-vestibulares inferiores, preparados com os instrumentos RaCe®.

The aim of this study was to analyze the taper and regularity of root canals prepared with rotary nickel-titanium system Race® and K3®, using angle reducer Dentfex®. The experiment involved mesial canals of thirty human molars, upper and lo-wer were randomly assigned to two groups of ffteen, according to the two types of rotary instruments: RaCe® and K3®. Since then, there was casting of root canals, to then subject the teeth to demineralization in 35% hydrochloric acid, thereby obtaining the same mold. These paterns were analyzed, where there was a taper and regularity of root canals prepared. The data were tabulated and analyzed statistically by the Mann-Whitney and Chi-square. The results indicate the predominance of regular conical forms, in all thirds (cervical, middle, apical) in mesial buccal and mesial lingual and palatine canals prepared with Race® and K3®, but statistically signifcant diference between the number of occurrence of irregular cylindrical shape along the lines of mesiobuccal canals below, prepared with RaCe®.

Discrepância entre método convencional de odontometria com referência padrão / Discrepancy between the conventional method of tooth length with standard reference

Este trabalho teve como objetivo comparar a discrepância entre método convencional de odontometria com a referência padrão determinada visualmente. Foram utilizadas 57 raízes de dentes humanos extraídos, sendo 17 anteriores, 20 pré-molares e 20 molares. Os dentes selecionados apresentavam ápices completos, ausência de fraturas apicais, coroas em bom estado de conservação, ausência de tratamento endodôntico e canais acessíveis até o forame apical. Antes de qualquer procedimento, foi realizada uma radiografa inicial. O dente foi medido com paquímetro digital (ponta de cúspide ou borda incisal até vértice apical) e os dados anotados. Após abertura coronária, exploração, esvaziamento dos canais radiculares e preparo do terço cervical foi realizada a odontometria visual do dente, através da visualização da lima tipo K-file pelo forame apical seguido de recuo de 1mm. Após, foi realizada uma radiografia de confirmação da odontometria, com uso de tela milimetrada. Os dados referentes à distância entre o zero apical e a ponta da lima na radiografia foram analisados e tabulados, e finalmente determinada a discrepância entre o limite apical determinado visualmente e radiograficamente. Concluiu-se que apenas 50,5% das raízes apresentam a odontometria visual coincidente com odontometria radiográfica. Os pré-molares foram o grupo de maior discrepância, seguidos pelos molares e anteriores.

This study aimed to compare the discrepancy between the conventional method of tooth length with a reference standard determined visually. We studied 57 extracted human tooth roots, being 17 previous, 20 premolars and 20 molar ones. The selected teeth had presented complete apexes, absence of apicais fractures, crowns in good condition of conservation, absence of endodontic treatment and canals accessible to the forame. Before any procedure, an initial periapical x-ray was performed. We measure the tooth with digital caliper (cusp tip or incisal edge until apical vertex) and we noted the data. After coronary opening, exploration, emptying of the root canals and preparation of third cervical was performed the visual odontometry of the tooth, that is the visualization of the K-file type for the followed apical forame of jib of 1mm. After this as performed a periapical radiography of confirmation of the odontometry, using screen millimeter. The referring data in the distance between the apical zero and the end of the file in the radiography, had been analyzed and tabulated, and finally determined the discrepancy between apical limit determined visually and radiographically. It was concluded that only 50.5% of the dental roots presents visual odontometry coincides with dental radiography odontometry. The premolars were the largest group of discrepancy, followed by molars and earlier.

Avaliação antimicrobiana de cones de guta-percha associados ao hidróxido de cálcio ou clorexidina / Antimicrobial evaluation of gutta-percha points associated to calcium hydroxide or chlorhexidine

Os microrganismos presentes no interior dos canais radiculares são os grandes responsáveis pelos insucessos endodônticos. Desta forma, a terapêutica endodôntica procura controlar estes microrganismos. Sendo assim, materiais obturadores deveriam ter não só as propriedades de adesão e biocompatibilidade, como também ação antimicrobiana. No presente estudo, avaliou-se a atividade antimicrobiana de cones de guta-percha utilizados na obturação dos canais radiculares contendo hidróxido de cálcio ou clorexidina. Os indicadores microbianos utilizados foram: Enterococcus faecalis (ATCC 29212) e Candida albicans (ATCC 10231). A atividade antimicrobiana foi avaliada por meio do teste por contato direto. Os cones testes foram imersos em 10 mL de suspensão microbiana, individualmente durante 30 minutos, com vistas ao processo de contaminação. Decorrido este período, os cones foram imersos por 5 minutos em solução salina, e transportados para 10 mL de meio de cultura Letheen Broth. Na seqüência, o material foi incubado a 37°C por 48 horas, em estufa bacteriológica, e avaliou-se a presença ou ausência de turvação do meio de cultura. A seguir, removeu-se 0,1 mL do meio de cultura e inoculou-se em 10 mL de Brain Heart Infusion em idênticos períodos e condições de incubação. Os resultados mostraram que apenas os cones de guta-percha contendo clorexidina apresentaram atividade antimicrobiana sobre os microrganismos estudados.

The microorganisms present in the root canals are the main responsible for endodontic failures. Thus, endodontic therapy seeks to control these microorganisms. Thus, filling materials should have not only the adhesion properties and biocompatibility, as well as antimicrobial. In this study, we evaluated the antimicrobial activity of gutta-percha used in the filling of root canals containing calcium hydroxide or chlorhexidine. The microbial indicators used were: Enterococcus faecalis (ATCC 29212) and Candida albicans (ATCC 10231). Antimicrobial activity was evaluated using the test by direct contact. The test cones were immersed in 10 mL of microbial suspension, individually for 30 minutes, with a view to the process of contamination. After this period, the cones were immersed for 5 minutes in saline, and transported to 10 ml of culture medium Letheen Broth. Subsequently, the material was incubated at 37ºC for 48 hours in a bacteriological incubator, and evaluated the presence or absence of turbidity of the culture. Next, we removed 0.1 mL of culture medium and inoculated in 10 mL of Brain Heart Infusion at the same time and incubation conditions. The results showed that only the gutta-percha points containing chlorhexidine presented antimicrobial activity on the microorganisms studied.

Capacidade seladora de remanescente de obturação do canal radicular frente a indicadores microbianos / Sealing ability of root canal filling remnants by microbial indicators

Estudou-se a capacidade seladora de remanescentes de obturação do canal radicular (4, 5 e 6mm), frente ao emprego do Sealapex e do EndoFill, valendo-se de diferentes indicadores microbianos. Para o teste de infiltração empregou-se uma plataforma, dividida em duas partes: câmara superior - onde foi introduzida a suspensão microbiana (contendo E. faecalis S. aureus, P. aeruginosa, B. subtilis e C. albicans) e uma câmara inferior, com o meio de cultura Brain Heart Infusion, onde 3 mm da região apical permaneceram imersos. O período de observação foi de 60 dias. Os dados obtidos foram submetidos ao teste de Kruskal-Wallis e Mann-Whitney. Os resultados mostraram infiltração microbiana em todos os grupos, não havendo diferenças significantes entre os cimentos estudados. Porém, quando se analisou os resultados dos níveis de remanescentes de obturação, entre 4 e 5 mm, e 5 e 6 mm não ocorreu diferenças significantes. Ao comparar os níveis de 4 e 6 mm pode-se constatar diferenças significantes.

This work aimed to evaluate the sealing ability of root canal filling remnants (4, 5 and 6mm), employing Sealapex and EndoFill, by means of differents microbial indicators. A platform was employed, which was split in two halves: an upper chamber - where the microbial suspension (containing E. faecalis + S. aureus + P. aeruginosa + B. subtilis + C. albicans); and a lower chamber containing the culture medium Brain Heart Infusion, in which 3 mm of the apical region of teeth were kept immersed. Interpretations of the time to occur microbial leakage were made daily for 60 days, using the turbidity of the culture medium which is indicative of microbial contamination, as a reference. The data obtained were submitted to the Kruskal-Wallis and Mann-Whitney tests. The outcomes didn't show any significant difference between the sealers assessed, when the time for microbial leakage was compared, and leakage was noted in all the comparative groups. When the results of the remaining obturation level were compared, between 4 and 5 mm and 5 and 6 mm, no significant differences were found; however, when 4 and 6 mm levels were compared significant differences were noted.