Immunohistological study of the effect of vascular Endothelial Growth Factor on the angiogenesis of mature root canals in rat molars

Abstract Tissue bioengineering has been applied to Endodontics to seek a more biological treatment. The presence of blood vessels is crucial for cell nutrition during tissue formation. Objective This study analysed the application of vascular endothelial growth factor (VEGF) in the angiogenesis of mature root canals. Material and methods Upper first molars of twelve 13-week old Wistar male rats were used. The root pulp of the mesiobuccal canal was removed and the root canal instrumented with K-files up to size #25. Periapical bleeding was induced into the root canal by introducing a #15 K-file beyond the apex. The teeth on the right side of the arch were filled up with blood clot (G1), whereas those on the left side were filled up with blood clot plus 50 ng/ml of VEGF (G2). Teeth were sealed with light-curing glass-ionomer cement and the animals were sacrificed after 60 days. The maxilla was dissected and fixed before obtaining serial sections for histological processing with haematoxylin-eosin (HE) and immunohistochemical factor-VIII. Immunohistochemical labelling was evaluated using scores for statistical analysis. Results Immunohistological analysis demonstrated the presence of angiogenesis in both groups, but with higher angiogenic maturation in G2 during the experimental period (p<0.05). HE staining showed connective tissue with absence of odontoblasts in all specimens. Conclusions It can be concluded that it is possible to obtain angiogenesis in mature root canals with or without the use of VEGF, although the latter tends to accelerate blood vessel formation.

Evaluacion de tres técnlcas de irrigación de conducto radicular frente a la actividad del enterococcusfaecalis / Evaluation of three techniques of root canal irrigation activity against enterococcusfaecalis

Objetivo: El objetivo de este estudio in vitro es comparar la eficacia antibacteriana de tres técnicas de irrigacion del conducto radicular: presion positiva, presion negativa y sónica frente a una cepa de enterococcusfaecalisatcc 2012. Materiales y Metodos: Raices de premolares extraidos calibrados a 16mm de longitud apico coronal fueron contaminados con Enterococcusfaecalis ATCC 29212 por 21 días y luego distribuidos aleateoriamente en 3 grupos experimentales con 24 especimenes cada uno: grupo 1, presion positiva con agujas 27G insertadas a 4mm de la longitud de trabajo; grupo 2. Fue irrigado activando las puntas endosónicas a 3mm; grupo3, con el sistema EndoVac. El volumen de irrigantes utilizado para todos los grupos fue de 13 ml. El grupo de control negativo fue irrigado con solución salina (volumen total: 13ml). Se tomaron muestras después de la irrigación para cultivarlas, a las 24 horas se contabilizaron las unidades formadoras de colonias (UFC's). Resultados: Los tres grupos experimentales fueron más efectivos que el grupo de control negativo en la disminución de la cantidad de bacterias. Conclusiones: No se encontró diferencia estadísticamente significativa entre los tres grupos evaluados.

Introduction: The different types of bacteria found in the root canal suggest that is necessary to pursue a correct cleaning of it; thus, by means of the irrigation techniques disinfection will improve. The aim of this in vitro study is to compare the antibacterial efficacy of 3 different irrigation techniques. Methods: Roots of premolars extracted teeth calibrated to 16 mm in apex-coronal direction were contaminated with Enterococcus faecalis ATCC 29212 within 21 days and then randomly divided into 3 experimental groups of 24 specimens: group 1, positive pressure irrigation with 27G needles inserted up to 4 mm short of the working length; group 2, same as group 1, but complemented with final irrigant activation by the EndoSonic tips; and group 3, irrigation with the Endo Vac system. The irrigants used in all experimental groups were NaOCI and ethylenediaminetetraacetic acid (EDTA). The diameter preparation was constant for the groups ISO .40/.04 (RaCe). The irrigants volume was 13mL for all the groups. The control group was irrigated with saline solution (total volume, 13 mL). Samples were taken after irrigation procedures for cultivation and successively colony-forming units (CFUs) were counted after 24 hours. Results: The 3 experimental groups were more effective than the negative control group in reducing bacteria. Conclusions: There was no statistical significant difference between the 3 techniques.

Efeito hemolítico e hemoglobinolítico de algumas soluçöes utilizadas como auxiliares no preparo biomecânico dos sistema de canais radiculares, através de diluiçöes em soro fisiológico normal: in vitro / Hemolytic and hemoglobinolytic effect of any solutions used as aids in biomechanical preparation of the root canal system by means of dilutions in normal saline solution: in vitro

Com a finalidade de avaliar o potencial citotóxico de algumas soluçöes utilizadas com auxiliares no preparo biomecânico dos sistema de canais radiculares, testou-se os efeitos hemolíticos e hemoglobinolíticos in vitro, de tais soluçöes através de diluiçäo em soro fisiológico normal. Foram testadas as seguintes soluçöes: soluçäo de hidróxido de cálcio a 0,2 por cento (água de cal), Tergentol, associaçäo de água de cal e Tergentol em duas proporçöes (HcT10 e Hct20), líquido de Dakin, soluçäo de Milton, soluçäo de Labarraque e soda clorada. Para tal, após a padronizaçäo da fragilidade globular das hemácias através de diluiçäo volume a volume de sangue venoso com soluçäo de Alsever modificada e armazenamento em geladeira por 4 dias, diluiu-se as soluçöes teste em concentraçöes decrescente de razäo variável em soro fisiológico puro, após o que procedeu-se o contato célula-material por 30 minutos, centrifugaçäo de tubos e leitura das densidades ópticas em Espectrofotômetro Espectra I no comprimento de onda de 545 mm. Após a ordenaçäo dos dados, calculou-se as médias para n=2 e os respectivos desvios padröes (DP) para cada diluiçäo das soluçöes. Os resultados permitiram concluir tratar-se de um método válido para tal finalidade por ser quantitativo, reprodutivo e de fácil execuçäo; que a adiçäo de um agente tênsio-ativo (tergentol) reduz significativamente o potencial hemolítico e hemoglobinolítico da água de cal; que o tipo e a concentraçäo das soluçöes säo determinantes no seu potencial hemolítico; e que as soluçöes de hipoclorito de sódio säo extremamente hemolítica e hemoglobinolíticas e, consequentemente, altamente citotóxicas