Influence of root canal sealer on the radiographic appearance of filling voids in maxillary single-rooted teeth

Objective: This study compared the influence of three epoxy resin-based sealers with distinct radiopacities on the observers' ability to detect root canal filling voids during radiographic analysis. Material and methods: The root canals of 48 extracted maxillary canines were prepared and divided into three groups. Each group was laterally condensed with one sealer (AH Plus (TM), Acroseal (R) or a non-radiopaque sealer), and a longitudinal void was simulated in half of the specimens from each group (n = 8). Buccolingual radiographs were obtained and randomly interpreted for voids by a radiologist and an endodontist in a blinded fashion. Teeth were cut and inspected under a microscope to confirm the position of void. Differences in sensitivity and specificity between groups and examiners were compared using the Fisher's Exact and McNemar tests, respectively (alpha = 0.05). Results: Significantly lower sensitivity levels (p<0.05) were observed in the coronal portion of fillings performed with both radiopaque sealers. Specificity values for Acroseal (R) were significantly higher (p<0.05) in the coronal and apical portions of fillings. Conclusion: The type of root canal sealer can affect the observers' ability to detect root canal filling voids during radiographic analysis of upper single-rooted teeth.

Endoscopic anatomy of the palatovaginal canal (palatosphenoidal canal)

Objectives/Hypothesis: Demonstrate the endoscopic anatomy of the palatovaginal (PV) canal and artery for identification and dissection of the vidian nerve during endoscopic transpterygoid approaches. Evaluate the length of the PV canal and its relation with the vidian nerve. Show that the traditionally known PV canal is a misnomer and should be renamed. Study Design: Experimental study: anatomical and radiological. Methods: Dissection of eight cadaveric heads was performed to demonstrate the endoscopic anatomy of the PV canal. Computed tomography scan analysis of 20 patients was used to evaluate the length of the PV canal, the angle formed between this canal and the vidian nerve, and the distance between the vidian canal and the PV canal. Study of 10 dry skull bases was performed to verify the structures involved in the formation of the PV canal. Results: Anatomic steps and foundations for dissection of the vidian nerve using the PV canal as a landmark were described. The mean length of the PV canal was 7.15 mm. The mean proximal distance between the vidian and the PV canal was 1.95 mm, and the mean distal distance was 4.14 mm. The mean angle between those canals was 48 degrees. The osteology study showed the vaginal process of the sphenoid bone did not contribute to the formation of the PV canal. Conclusions: Our anatomic investigations, radiologic studies, and surgical experience demonstrate the important anatomic relationship of the PV canal with the vidian canal and the relevance of the PV canal as a surgical landmark in endoscopic endonasal transpterygoid approaches. Anatomically, PV canal is a misnomer and should be replaced with palatosphenoidal canal.

Analysis of kinematic, kinetic and electromyographic patterns during root canal preparation with rotary and manual instruments

Objective: This study assessed the muscular activity during root canal preparation through kinematics, kinetics, and electromyography (EMG). Material and Methods: The operators prepared one canal with RaCe rotary instruments and another with Flexofiles. The kinematics of the major joints was reconstructed using an optoelectronic system and electromyographic responses of the flexor carpi radial's, extensor carpi radialis, brachioradialis, biceps brachii, triceps brachii, middle deltoid, and upper trapezius were recorded. The joint torques of the shoulder, elbow and wrist were calculated using inverse dynamics. In the kinematic analysis, angular movements of the wrist and elbow were classified as low risk factors for work-related musculoskeletal disorders. With respect to the shoulder, the classification was medium-risk. Results: There was no significant difference revealed by the kinetic reports. The EMG results showed that for the middle deltoid and upper trapezius the rotary instrumentation elicited higher values. The flexor carpi radialis and extensor carpi radialis, as well as the brachioradialis showed a higher value with the manual method. Conclusion: The muscular recruitment for accomplishment of articular movements for root canal preparation with either the rotary or manual techniques is distinct. Nevertheless, the rotary instrument presented less difficulty in the generation of the joint torque in each articulation, thus, presenting a greater uniformity of joint torques.

Root and Root Canal Morphology of Four-rooted Maxillary Second Molars: A Micro-Computed Tomography Study

Introduction: This study examined the anatomy of 4-rooted maxillary second molars by using micro computed tomography. Methods: Twenty-five 4-rooted maxillary second molars were scanned to evaluate the size and curvature of the roots; the distance and spatial configuration between some anatomical landmarks; the number of root canals and the position of apical foramina; the occurrence of fusion of roots and enamel pearls; the configuration of the canal at the apical third; the cross-sectional appearance, the volume, and surface area of the root canals. Data were compared by using analysis of variance post hoc Tukey test (alpha = 0.05). Results: The specimens were classified as types I (n = 16), II (n = 7), and III (n = 2). The size of the roots was similar (P > .05), and most of them presented straight with 1 canal, except the mesiobuccal that showed 2 canals in 24% of the samples. The configuration of the pulp chamber was mostly irregular quadrilateral-shaped. The lowest mean distance of the orifices was observed between the buccal roots (P < .05). Accessory canals were present mostly in the apical third. Location of the apical foramina varied considerably. Fusion of roots and enamel pearls occurred in 44% and 8% of the samples, respectively. Mean distance from the pulp chamber floor to the furcation was 2.15 +/- 0.57 mm. No statistical differences were found in the bi-dimensional and 3-dimensional analyses (P > .05). Conclusions: All analyzed parameters showed differences between roots, except for the length of the roots, the configuration of the canals at the apical third, cross-sectional appearance, volume, and surface area of the canals. (J Endod 2012;38:977-982)

Evaluation of epoxy resin sealer after three root canal filling techniques by confocal laser scanning microscopy

The aim of this study was to evaluate the penetration of endodontic sealer into the dentin tubules, the integrity of the sealer layer perimeter, and the sealer area at the apical third after different filling techniques by confocal laser scanning microscopy (CLSM). Forty-five mandibular premolars were mechanically prepared with ProTaper files, until F5 file. Thereafter, they were filled with an epoxy-resin sealer (AH Plus) mixed with Rhodamine B dye (0.1% proportion) and allocated in three groups: Group 1, single master cone; Group 2, cold lateral compaction; and Group 3, Thermafil. For confocal laser scanning microscopy analysis, the specimens were transversely sectioned at 4 mm from the apex. The images at x10 and x40 were analyzed by Imagetool 3.0 software. Significant differences were not found among the three experimental groups according the dentin-impregnate area by the sealer (P = 0.68) and between the sealer and root canal perimeter (P = 0.18). However, root canal filling techniques were significantly different when apical sealer areas were compared (P = 0.001). Thermafil group showed smaller sealer areas (8.09%) while cold lateral compaction and gutta-percha master cone showed similar areas (17.37 and 21.18%, respectively). The dentin-impregnated area was not dependent on the root canal filling technique. Single master cone, cold lateral condensation and Thermafil techniques presented integrity of the sealer perimeter close to 100% and Thermafil resulted in a significantly thinner sealer layer. Microsc. Res. Tech. 75:12771280, 2012. (C) 2012 Wiley Periodicals, Inc.

Effect of the root canal final rinse protocols on the debris and smear layer removal and on the push-out strength of an epoxy-based sealer

The aim of the present study was to evaluate the efficacy of QMiX, SmearClear, and 17% EDTA for the debris and smear layer removal from the root canal and its effects on the push-out bond strength of an epoxy-based sealer by scanning electron microscopy (SEM). Forty extracted human canines (n = 10) were assigned to the following final rinse protocols: G1-distilled water (control), G2–17% EDTA, G3-SmearClear, and G4-QMiX. The specimens were submitted to a SEM analysis to evaluate the presence of debris and smear layer, respectively, in the apical or cervical segments. In sequence, forty extracted human maxillary canines with the root canals instrumented were divided into four groups (n = 10) similar to the SEM analysis study. After the filling with AH Plus, the roots were transversally sectioned to obtain dentinal slices. The specimens were submitted to a push-out bond strength test using an electromechanical testing machine. The statistical analysis for the SEM and push-out bond strength studies were performed using the Kruskal–Wallis and Dunn tests (α = 5%). There was no difference among the G2, G3, and G4 efficacy in removing the debris and smear layer (P > 0.05). The efficacy of these groups was superior to the control group. The push-out bond strength values of G2, G3, and G4 were superior to the control group. The ability to remove the debris and smear layer by SmearClear and QMiX was as effective as the 17% EDTA. The final rinse with these solutions promoted similar push-out bond strength values.

Influence of apical foramen lateral opening and file size on cemental canal instrumentation

Since instrumentation of the apical foramen has been suggested for cleaning and disinfection of the cemental canal, selection of the file size and position of the apical foramen have challenging steps. This study analyzed the influence of apical foramen lateral opening and file size can exert on cemental canal instrumentation. Thirty-four human maxillary central incisors were divided in two groups: Group 1 (n=17), without flaring, and Group 2 (n=17), with flaring with LA Axxess burs. K-files of increasing diameters were progressively inserted into the canal until binding at the apical foramen was achieved and tips were visible and bonded with ethyl cyanoacrylate adhesive. Roots/files set were cross-sectioned 5 mm from the apex. Apices were examined by scanning electron microscopy at ×140 and digital images were captured. Data were analyzed statistically by Student’s t test and Fisher’s exact test at 5% significance level. SEM micrographs showed that 19 (56%) apical foramina emerged laterally to the root apex, whereas 15 (44%) coincided with it. Significantly more difficulty to reach the apical foramen was noted in Group 2. Results suggest that the larger the foraminal file size, the more difficult the apical foramen instrumentation may be in laterally emerged cemental canals.

Tratamento percutâneo vs. cirúrgico da persistência do canal arterial em crianças e adolescentes

INTRODUÇÃO: Estudos comparando os métodos percutâneo e cirúrgico no tratamento da persistência do canal arterial (PCA) são raros na literatura. Nosso objetivo foi realizar análise comparativa entre os dois métodos de tratamento da PCA, enfatizando os aspectos de eficácia e morbidade. MÉTODOS: Estudo observacional com 2 coortes de crianças e adolescentes > 5 kg e < 14 anos, portadores de PCA, tratados durante um projeto de avaliação de incorporação de novas tecnologias ao Sistema Único de Saúde (SUS), realizado em um hospital cardiológico de excelência, em parceria com o Ministério da Saúde do Brasil. Foi feita análise prospectiva no grupo percutâneo entre 2009 e 2011 e retrospectiva no grupo cirúrgico entre 2006 e 2011. RESULTADOS: Foram incluídos 80 pacientes no grupo percutâneo (60% do sexo feminino) e 39 no grupo cirúrgico (51% do sexo feminino; P = 0,37). A mediana de idade e de peso dos grupos percutâneo e cirúrgico foi de 39,4 meses vs. 25,5 meses (P = 0,04) e de 14 kg vs. 11,1 kg (P = 0,052), respectivamente. No grupo percutâneo, 78 pacientes (92%) tinham PCA do tipo A e o diâmetro mínimo do canal à angiografia foi de 2,5 ± 1,2 mm. As próteses mais utilizadas foram Amplatzer®, molas de Gianturco e CeraTM. A técnica cirúrgica mais utilizada foi a clipagem. A taxa de sucesso dos procedimentos foi de 100% nos dois grupos. O grupo cirúrgico apresentou maiores taxas de complicação, incluindo quilotórax, infecções, necessidade de hemoderivados, hipertensão arterial sistêmica e uso de opioides, como também maior necessidade de terapia intensiva. A mediana do tempo de internação foi de 1,3 dia no grupo percutâneo e de 7,9 dias no grupo cirúrgico (P < 0,01). À alta hospitalar, as taxas de oclusão foram semelhantes nos dois grupos (91% no grupo percutâneo e 87% no grupo cirúrgico; P = 0,71). CONCLUSÕES: Em decorrência da menor morbidade, do menor tempo de internação e da igual eficácia, o tratamento percutâneo da PCA deve ser considerado a modalidade terapêutica de escolha para pacientes selecionados.

Levantamento dos fatores de enriquecimento do As e metais em sedimentos superficiais do Canal de Bertioga (SP), Brazil

Em virtude do desenvolvimento econômico do litoral paulista, ao longo do século XX, ocorreram modificações no ambiente costeiro proveniente de construções de rodovias, melhorias na estrutura portuária de Santos e implantação do pólo petroquímico de Cubatão. Localizado na porção mais a NE do complexo estuarino da Baixada Santista, o Canal de Bertioga, com aproximadamente 25 km de extensão, faz a ligação entre o oceano e o alto estuário santista. O canal é considerado como uma conexão secundária do oceano ao complexo estuarino de Santos, com sua desembocadura a nordeste localizada próxima a cidade de Bertioga, e a desembocadura oposta próxima ao canal do alto estuário santista. Assim, esse trabalho teve como objetivo fazer um levantamento dos fatores de enriquecimento de As, Cr, Cu, Mn, Ni, Pb e Zn em 147 amostras de sedimentos superficiais coletadas ao longo do Canal. As amostras foram inicialmente liofilizadas, procedendo-se a digestão ácida e determinação dos elementos de interesse por espectrometria de emissão ótica por plasma indutivamente acoplado (ICP-OES). Os resultados obtidos mostraram-se distribuídos dentro de dois padrões, um deles apresentando maiores valores de fator de enriquecimento na desembocadura sul, próximo à região de Guarujá e o outro, na desembocadura norte, o qual sofre grande influência do estuário Santista e das inúmeras fontes ali presentes

Indicadores químicos e biológicos na avaliação da qualidade do sedimento do Canal do Porto de Santos (SP, Brasil)

O Porto de Santos, inaugurado oficialmente em fevereiro de 1892, é o principal porto brasileiro e o maior da América Latina, responsável por cerca de um quarto da movimentação da balança comercial do país e mais de 60 milhões de toneladas de cargas diversas. Impactos na área decorrem da grande quantidade de embarcações e necessidade de dragagens periódicas, além da existência de uma extensa ocupação desordenada de suas margens e da presença de um complexo de indústrias e usinas na região. A qualidade do sedimento do Canal do Porto foi avaliada por meio de testes de toxicidade (agudo e crônico), de análises químicas (metais e hidrocarbonetos) e da estrutura da comunidade bentônica. O sedimento foi coletado em agosto de 2012 com pegador de fundo de 0,05m2 (3 réplicas para bentos) ao longo do Canal. Foram determinados 10 pontos de coleta para as análises químicas e de toxicidade, sendo 3 pontos para a análise da macrofauna bentônica (início, meio e fim do Canal). A distância entre o primeiro e o último ponto foi de 16 km. A avaliação conjunta dos resultados indicou um impacto maior na região mais interna do Canal. Na parte mais próxima ao complexo industrial de Cubatão foram observadas as maiores concentrações de metais e hidrocarbonetos, associadas a baixos valores de diversidade e riqueza, além de uma alta densidade do gastrópodo Heleobia australis. No centro do Canal do Porto, houve uma maior contribuição de indicadores de esgoto, presença de hidrocarbonetos e metais em concentrações relativamente altas, valores extremamente baixos de densidade, diversidade e riqueza da macrofauna bentônica, menor sobrevivência do anfípodo Tiburonella viscana (toxicidade aguda) e baixa taxa de eclosão de ovos do copépodo Nitokra sp (toxicidade crônica). Esse ponto encontra-se próximo a uma grande quantidade de habitações precárias, cujo esgoto é lançado diretamente no Canal.

Analysis of genetic lineages and their correlation with virulence genes in enterococcus faecalis clinical isolates from root canal and systemic infections

Introduction: Enterococcus faecalis is a member of the mammalian gastrointestinal microbiota but has been considered a leading cause of hospital-acquired infections. In the oral cavity, it is commonly detected from root canals of teeth with failed endodontic treatment. However, little is known about the virulence and genetic relatedness among E. faecalis isolates from different clinical sources. This study compared the presence of enterococcal virulence factors among root canal strains and clinical isolates from hospitalized patients to identify virulent clusters of E. faecalis. Methods: Multilocus sequence typing analysis was used to determine genetic lineages of 40 E. faecalis clinical isolates from different sources. Virulence clusters were determined by evaluating capsule (cps) locus polymorphisms, pathogenicity island gene content, and antibiotic resistance genes by polymerase chain reaction. Results: The clinical isolates from hospitalized patients formed a phylogenetically separate group and were mostly grouped in the clonal complex 2, which is a known virulent cluster of E. faecalis that has caused infection outbreaks globally. The clonal complex 2 group comprised capsule-producing strains harboring multiple antibiotic resistance and pathogenicity island genes. On the other hand, the endodontic isolates were more diverse and harbored few virulence and antibiotic resistance genes. In particular, although more closely related to isolates from hospitalized patients, capsuleproducing E. faecalis strains from root canals did not carry more virulence/antibiotic genes than other endodontic isolates. Conclusions: E. faecalis isolates from endodontic infections have a genetic and virulence profile different from pathogenic clusters of hospitalized patients’ isolates, which is most likely due to niche specialization conferred mainly by variable regions in the genome.

Acto de inauguración de la exposición El Gran Canal de Venecia en la Biblioteca de Arquitectura de la ULPGC

Evento celebrado el 24 de octubre de 2011 que consistió en la presentación de la muestra El Gran Canal de Venecia, a cargo de D. Enrique Solana Suárez como Director de la Escuela de Arquitectura de Las Palmas, D. Héctor López Campos por la Biblioteca de Arquitectura, Dña. Ruth Cebrián Jorge como alumna de la Escuela y D. Juan Ramírez Guedes como personal docente de la EA. Lugar: Biblioteca de Arquitectura de la Universidad de Las Palmas de Gran Canaria. Campus del Tafira. Las Palmas de Gran Canaria.