The aim of the study was to evaluate the photodynamic therapy (PDT) effect on root canals contaminated with Enterococcus faecalis using a light emitting diode (LED) light and a curcumin solution (CUR) as photosensitizer (PS). Eighty root canals from uniradicular human teeth were prepared with Protaper Universal rotary system and contaminated with E. faecalis for 21 days. They were divided as: GIa-PDT (CUR, pre-irradiation for 5 + 5 min of irradiation); GIb-PDT (CUR, pre-irradiation for 5 + 10 min of irradiation); GIIa-(CUR, pre-irradiation for 5 + 5 min without irradiation); GIIb-(CUR pre-irradiation for 5 + 10 min of irradiation); GIIIa-(physiological solution and irradiation for 5 min); and GIIIb-(physiological solution and irradiation for 10 min); positive and negative control groups. Collections from root canals were made at time intervals of 21 days after contamination, immediately after treatment, and 7 days after treatment, and submitted to colony forming units per milliter (CFU mL(-1)) counts. The data were submitted to ANOVA and Tukey multiple comparison tests, at a level of significance of 5 %. In the immediate post-treatment collection, group GIa showed greater bacterial reduction in comparison with GIIa, GIIb, GIIIa, GIIIb, and positive control (P < 0.05). At 7 days post-treatment, GIa showed significant bacterial reduction only in comparison with GIIIa (P < 0.05). Curcumin as sensitizer was effective by 5 min LED irradiation but not by 10 min irradiation PDT using LED light, and curcumin as PS was not effective in eliminating E. faecalis. No difference was observed for periods of irradiation.

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The cleaning capacity of hybrid and rotary instrumentation techniques in mesial flattened canals of mandibular first molars was evaluated by morphometrical analysis in this study. Twenty human mandibular first molars were randomly assigned into two groups, according to instrumentation technique, as follows: group 1, instrumentation with ProTaper Starter Kit (Dentsply/Maillefer) rotary system; group 2, manual instrumentation using K files (Dentsply/Maillefer) by crown-down technique in middle and apical thirds, cervical preparation with Gates-Glidden #1 and #2 (Dentsply/Maillefer) burs, and to finalise the preparation, ProTaper F2 and F3 rotary files. Serial transverse cross-sections (5 µm) of the apical third, stained with hematoxylin and eosin, were analysed at 100× original magnification. The images were submitted to morphometrical analysis with an integration grid to determine the percentage of root canal area with debris. Statiscal analysis (t-Student, P < 0.05) showed significant difference between the techniques (P < 0.05), although neither completely cleaned the root canal.

Aim:The aim of this study was to assess the cleaning capacity of the Protaper system using motor-driven or manual instrumentation.Materials and Methods:Ten mandibular molars were randomly separated into 2 groups (n = 5) according to the type of instrumentation performed, as follows: Group 1 - instrumentation with rotary nickel-titanium (Ni-Ti) files using ProTaper Universal System (Dentsply/Maillefer); and, Group 2 - instrumentation with Ni-Ti hand files using ProTaper Universal (Dentsply-Maillefer). Afterwards, the teeth were sectioned transversely and submitted to histotechnical processing to obtain histological sections for microscopic evaluation. The images were analyzed by the Corel Photo-Paint X5 program (Corel Corporation) using an integration grid superimposed on the image.Results:Statistical analysis (U-Mann-Whitney - P < 0.05) demonstrated that G1 presented higher cleaning capacity when compared to G2.Conclusions:The rotary technique presented better cleaning results in the apical third of the root canal system when compared to the manual technique.

Resumo: Os modelos de experimentação animal constituem uma importante ferramenta na pesquisa científica. Sabe-se que essa prática deve estar baseada em princípios bioéticos, seja para impor limites de dor e sofrimento, como para fiscalizar instalações e procedimentos. Assim, o presente estudo teve por objetivo levantar e apresentar as normas atuais que regulamentam as pesquisas em animais no Brasil comprando-as a outros países, bem como fomentar reflexões bioéticas sobre esse mote. Para isso, apresentamos a legislação brasileira vigente e conduzimos uma revisão e discussão da literatura internacional. A busca de artigos foi realizada na base de dados PubMed, utilizando como palavra-chave os termos "bioética" e "bem-estar do animal". Foram incluídos dezenove artigos, publicados entre os anos de 1997 a 2013. Concluiu-se que é evidente a contribuição dos animais para pesquisas científicas de diversas áreas. Cabe moralmente ao Homem, como ser racional, garantir um tratamento digno aos animais que contribuem para a pesquisa. A forma mais segura de seguir este caminho é estabelecendo leis claras e pesquisas bem delineadas, que envolvam a sociedade para designar normas éticas. Dessa forma, o bem-estar animal estaria garantido.Palavras-chave: bioética, ética em pesquisa, experimentação animal, bem-estar do animal Investigación con animales: una reflexión bioéticaResumen: Los modelos animales son una herramienta importante en la investigación científica. Se sabe que esta práctica debe basarse en principios bioéticos, sea para imponer límites sobre el dolor y el sufrimiento, o para inspeccionar las instalaciones y procedimientos. Este estudio tuvo el objetivo de evaluar y presentar las normas vigentes que rigen la investigación con animales en Brasil, comparándolas con otros países, así como fomentar la reflexión bioética sobre este tema. Para eso, presentamos la legislación brasileña vigente y realizamos una revisión y discusión de la literatura internacional. La búsqueda de artículos fue realizada en la base de datos PubMed, usando las palabras-clave "bioética" y "bienestar del animal". Se incluyeron diecinueve artículos publicados entre 1997 e 2013. Se concluyó que es evidente la contribución de los animales para la investigación científica de varias áreas. Cabe moralmente al ser humano, como ser racional, asegurar un tratamiento humanitario de los animales que contribuyen con la investigación. La forma más segura de seguir este camino es estableciendo leyes claras e investigaciones bien delineadas, que involucren la sociedad para designar normas éticas. Así, el bienestar de los animales estaría garantizado.Palabras clave: bioética, ética en investigación, experimentación animal, bienestar del animal Animal research. A bioethical reflectionAbstract: Animal models are an important tool in scientific research. It is known that this practice must be based on bioethical principles in order to impose limits about pain and suffering, or for inspecting proceedings and research site. This study has as aim to evaluate and prese...

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Aim:The aim of the following study is to evaluate the cleaning capacity of a hybrid instrumentation technique using Reamer with Alternating Cutting Edges (RaCe) system files in the apical third of mesial roots of mandibular molars.Materials and Methods:Twenty teeth were selected and separated into two groups (n = 20) according to instrumentation technique as follows: BioRaCe - chemomechanical preparation with K-type files #10 and #15; and files BioRaCe BR0, BR1, BR2, BR3, and BR4; HybTec - hybrid instrumentation technique with K-type files #10 and #15 in the working length, #20 at 2 mm, #25 at 3 mm, cervical preparation with Largo burs #1 and #2; apical preparation with K-type files #15, #20, and #25 and RaCe files #25.04 and #30.04. The root canals were irrigated with 1 ml of 2.5% sodium hypochlorite at each change of instrument. The specimens were histologically processed and photographed under light optical microscope. The images were inserted onto an integration grid to count the amount of debris present in the root canal.Results:BioRaCe presented the highest percentage of debris in the apical third, however, with no statistically significant difference for HybTec (P > 0.05).Conclusions:The hybrid technique presented similar cleaning capacity as the technique recommended by the manufacturer.

Aim:To evaluate the apical transportation induced by two instrumentation techniques in severely curved simulated canals.Materials and Methods:Forty simulated canals were divided into two groups (n = 20), according to the following instrumentation techniques: ProTaper Universal Manual System and a hybrid technique. The simulated canals in the ProTaper group were prepared following the technique recommended by the manufacturer: SX files in the cervical third of the root canal and S1, S2, and F1 files up to the working length. In the hybrid group, preparation was performed with K-files sizes 15, 20, and 25 to the working length, followed by cervical preparation with Gates Glidden burs 1, 2, and 3. Apical finishing was performed with the ProTaper manual files S2 and F1. To analyze apical transportation, the simulated canals were photographed before and after preparation at ×8. The images of the root canals pre- and post-instrumentation were superimposed to measure the distance between the inner and outer walls along the first 3 mm of the apical third.Results:The hybrid group presented the highest apical transportation values; however, with no statistically significant difference in comparison with the ProTaper group (P > 0.05).Conclusions:Both techniques induced similar apical transportation in the original path of the simulated root canals.