The aim of this study was to evaluate the capacity of conventional irrigation, passive ultrasonic irrigation (PUI), and Easy Clean for removing calcium hydroxide‐based root canal dressing from oval root canals. Thirty mandibular uniradicular incisors with oval canals were used, and subjected to chemical–mechanical preparation with Reciproc R40 instruments. The main canal was filled with a paste based on Ca(OH)2 P.A., iodoform and propylene glycol in the ratio of 3:1:1. The teeth were stored in 100% humidity at a temperature of 37°C for 14 days. Afterwards, the teeth were divided into three groups (n = 10) according to the method of irrigation used (conventional irrigation, PUI, and Easy Clean). The specimens were analyzed by computed microtomography at three time intervals: before placing the root canal dressing, with the root canal dressing in place, and after application of the irrigation methods for removing it. The data were submitted to Kruskal–Wallis and Dunn tests for analyzing the canal as a whole, and Friedman and Dunn for analyzing the root thirds. The results showed that conventional irrigation was less efficient for removing the root canal dressing in comparison with the methods that agitated the irrigant solution (p < .05). When the root canal was analyzed as a whole, Easy Clean, and PUI were similar (p > .05). In analysis of the thirds, Easy Clean was more efficient than conventional irrigation in all the thirds, while PUI showed this behavior only in the cervical third (p < .05). The authors concluded that in oval canals, none of the irrigation methods were capable of removing all the root canal dressing, however, the methods that agitated the irrigant solution were more efficient than conventional irrigation.

Objetivo: Verificar in vivo a precisão e confiabilidade de leitura do localizador foraminal eletrônico Joypex 5 ® utilizando o microscópio eletrônico de varredura na aferição das medidas obtidas pelo aparelho. Método: Foram triados pacientes com indicação para extração por motivos ortodônticos e periodontais, o que resultou em amostra de 14 canais. Os dentes foram previamente radiografados com a intenção de detectar perfurações, tratamentos endodônticos prévios e calcificações. Realizadas as aberturas coronárias, os terços cervical e médio foram preparados e procederam-se as leituras no ponto correspondente no display do aparelho ao forame apical. Após a obtenção da medida a lima foi removida e subtraiu-se 1mm do comprimento lido em paquímetro digital para, então, fixar o instrumento e realizar a exodontia. Na seqüência foi realizado um desgaste em uma das paredes da região apical, objetivando visualizar a ponta do instrumento e a continuidade do canal até a real saída do forame apical. A distância entre a ponta da lima e a real saída foraminal foi medida com o auxílio de microscopia eletrônica de varredura. Resultados: A média das medidas foi 0,87 mm (0,42mm). O teste T para amostras independentes revelou que os dados mostraram-se semelhantes (p > 0,05) entre os valores experimentais encontrados (da ponta do instrumento ao forame apical) e o valor hipotético testado de 1 mm. Conclusões: O estudo concluiu que o localizador foraminal eletrônico Joypex 5 ® demonstrou ser preciso e confiável na determinação de um comprimento de trabalho eficiente e seguro para o tratamento endodôntico. Endodontia; Odontometria; Equipamentos e provisões. Objective: To evaluate in vivo the measurement accuracy and reliability of the electronic apex locator Joypex 5 ® using a scanning electron microscope to assess the measurements obtained with the tested device. Method: Patients with indication for tooth extraction for orthodontic and periodontal reasons were screened, providing a sample of 14 root canals. The teeth were first radiographed for detecting perforations, previous endodontic treatments and calcifications. After preparation of access cavities, the coronal and middle thirds were prepared and the electronic measurements were made on the point corresponding to the apical foramen of the apex locator's display. After the electronic reading, the file was removed from the canal, 1 mm was subtracted from the measurement obtained using a digital caliper, and the apex locator was fixed for extraction of the tooth. Next, grinding was performed on an apical wall in order to visualize the tip of the file and canal integrity up to the actual apical foramen opening. The distance between the file tip and the actual apical foramen opening was measured by scanning electron microscopy. Results: The mean of the obtained measurements was 0.87 mm (0.42 mm). The t test for independent samples revealed statistical similarity (p>0.05) among the obtained values (from the file tip to actual apical foramen) and the hypothetical 1 mm value. Conclusio...

Introduction: There is a possibility of intracanal medication remain in the root canal even after its removal prior to obturation. The present study aims to evaluate under scanning electron microscopy the persistence of residues in the root canal from calcium hydroxide medications prepared with different vehicles. Methods: Thirtysix bovine incisors had their crowns removed, the root canals prepared and were assigned randomly to six different experimental groups, according to the intracanal medication used. Group I (control) received no intracanal medication, whereas root canals of Group II were filled with P.A. calcium hydroxide. Group III received a mixture of Ca(OH) 2 and saline solution, in Group IV glycerin was used as vehicle, and Groups V and VI received Ca(OH) 2 mixed with propylene glycol or polyethylene glycol 400, respectively. After one week, medication was removed, roots were split and the canals observed under the scanning electron microscope. Representative photomicrographs of the apical third of each experimental group were observed and analyzed quantitatively by means of a grid, with results expressed in percentage of canal walls covered by debris. Results: Statistical analysis (one-way ANOVA and Tukey's post hoc test, α=0.05) revealed significant differences between groups, indicating higher amounts of Ca(OH) 2 residues in the canals where propylene glycol or polyethylene glycol were used as vehicles. The dentinal walls of the canals that received pure P.A. calcium hydroxide or its association to glycerin presented amounts of debris similar to the control group. Conclusions: Ca(OH) 2 P.A. based medications or its association to glycerin allows an easier removal from the root canal.