Efficacy of passive ultrasonic irrigation in removing root filling material during endodontic retreatment

Abstract

ResumoIntrodução: O retratamento endodôntico requer a remoção de todos os materiais obturadores para a limpeza, o preparo e a obturação subsequentes do canal radicular. Objetivo: Avaliar a eficácia da Irrigação Ultrassônica Passiva (IUP) na remoção de material obturador residual após a desobturação com sistema rotatório de níquel-titânio. Material e método: Dezoito raízes mesiais de molar inferior com istmos foram preparadas e obturadas. A obturação foi removida com o sistema rotatório ProTaper Retratamento e limas manuais tipo K. Os espécimes foram randomizados em dois grupos (n = 9), ambos irrigados com NaOCl a 2,5% e EDTA a 17%. No grupo Convencional, a seringa de irrigação foi utilizada. No grupo da IUP, a técnica da IUP foi usada. As raízes foram seccionadas longitudinalmente e avaliadas em estereomicroscópio. O teste t de Student foi usado para comparar os grupos e o modelo linear geral foi usado para comparar os terços cervical, médio e apical dentro de cada grupo, no que diz respeito a porcentagem de material obturador residual. Resultado: Não houve diferença estatisticamente significante entre os grupos, independentemente do terço do canal radicular analisado (P > 0.05). No grupo da IUP, o terço apical mostrou uma porcentagem significativamente mais alta de material obturador residual quando comparado aos terços cervical (P = 0.038) e médio (P = 0.029). Conclusão: A IUP não foi mais eficaz do que a técnica convencional na remoção de material obturador remanescente durante o retratamento endodôntico em canais radiculares com anatomia complexa.Descritores: Irrigação; retratamento; canal radicular; ultrassom. AbstractIntroduction: The aim of endodontic retreatment is to remove the previous root filling materials completely to allow for the subsequent steps of cleaning, canal shaping and filling replacement. Objective: To evaluate the efficacy of passive ultrasonic irrigation (PUI) in the removal of residual root filling material after removing the bulk of the root filling with nickel-titanium rotary instruments. Material and method: Eighteen mesial isthmus-containing roots of human mandibular molars were prepared and filled. The root canal filling was removed with the ProTaper Retreatment system and K-files. The specimens were randomized into 2 groups (n = 9), both irrigated with 2.5% NaOCl and 17% EDTA. In the conventional group, an irrigation syringe was used. In the PUI group, the PUI technique was used. The roots were sectioned longitudinally and evaluated under stereomicroscopy. Student's t test was used to compare groups and the general linear model was used to compare the apical, cervical, and middle root thirds within each group, in regard to the percentages of remaining residual filling material. Result: There was no statistically significant intergroup difference, irrespective of which root third was evaluated (P > 0.05). In the PUI group, the apical third showed a significantly higher percentage of residual filling material, in comparison with the cervical (P = 0.038) and middle (P = 0.029) thir...

Comparison of the Efficacy of Different Techniques for the Removal of Root Canal Filling Material in Artificial Teeth: A Micro-Computed Tomography Study

“…We found that the amount of residual filling material was smaller in the PUI group than in the conventional group, with the exception of the apical region. This result was similar to that of a previous study, where the PUI technique was found to be more effective than the conventional technique for the removal of root canal filling material from the cervical and middle thirds during endodontic retreatment [19]. Additional PUI retreatment eliminates sealer and GP debris beyond the curvature or in areas that cannot be accessed by conventional retreatment files.…”