Rafael Binato Junqueira

Detection of Fractured Endodontic Instruments in Root Canals: Comparison between Different Digital Radiography Systems and Cone-beam Computed Tomography

Introduction This study compared the detection of fractured instruments in root canals with and without filling by periapical radiographs from 3 digital systems and cone‐beam computed tomographic (CBCT) images with different resolutions. Methods Thirty‐one human molars (80 canals) were used. Root canals were divided into the following groups: the control group, without fillings; the fracture group, without fillings and with fractured files; the fill group, filled; and the fill/fracture group, filled and with fractured files. Digital radiographs in ortho‐, mesio‐, and distoradial directions were performed in 2 semidirect systems (VistaScan [Dürr Dental, Beitigheim‐Bissinger, Germany] and Express [Instrumentarium Imaging, Tuusula, Finland]) and a direct system (SnapShot [Instrumentarium Imaging]). CBCT images were acquired with 0.085‐mm and 0.2‐mm voxel sizes. All images were assessed and reassessed by 4 observers for the presence or absence of fractured files on a 5‐point scale. The sensitivity, specificity, and accuracy were calculated. Results In the absence of filling, accuracy values were high, and there were no statistical differences among the radiographic techniques, different digital systems, or the different CBCT voxels sizes. In the presence of filling, the accuracy of periapical radiographs was significantly higher than CBCT images. In general, SnapShot showed higher accuracy than VistaScan and Express. Conclusions Periapical radiographs in 1 incidence were accurate for the detection of fractured endodontic instruments inside the root canal in the absence or presence of filling, suggesting that this technique should be the first choice as well as the direct digital radiographic system. In the presence of filling, the decision to perform a CBCT examination must take into consideration its low accuracy.

Ankylosis of Permanent First Molar: Diagnosis by Cone Beam Computed Tomography

Ankylosis is an anomaly of tooth eruption characterized by the fusion of cementum and alveolar bone, and may affect from small regions to the entire root surface. Clinical assessment combined with imaging exams can aid diagnosis. Radiographic testing enables assessing only proximal regions of possibly affected roots. Whereas cone beam computed tomography (CBCT) allows a three-dimensional assessment of axial, coronal, and sagittal planes of all dental extension, eliminating thus overlapping images and helping to confirm the correct diagnosis. The present study contains a case report of a male patient with ankylosis in tooth 16 diagnosed by CBCT, aiming at providing information for dentists about this anomaly, its characteristics and situations in which CBCT should be indicated.

Influence of Irrigants in Association with Ultrasound for Cleaning Root Dentin Surface after Post Space Preparation: EDS Analysis

Este estudio evaluo la limpieza de la preparacion para el espacio de los postes despues de diferentes protocolos de irrigacion, asociados o no al uso de ultrasonido. Treinta y seis raices unirradiculares de bovinos fueron instrumentados con sistema rotatorio, irrigadas con un 1 % de hipoclorito y rellenadas con el sellador Ah Plus y conos de gutapercha. Despues de siete dias en horno a 37 °C, dos tercios de la obturacion del canal se removio por perforacion y la preparacion del espacio para los postes fueron irrigadas con 2,5 % de NaOCl (grupo NaOCl); Clorhexidina 0,2 % (grupo CLX); agua destilada (grupo agua); 2,5 % NaOCl + ultrasonido (grupo NaOCl - US); 0,2 % de clorhexidina + US (Grupo CLX - US); y agua + US (grupo Agua - US). Las raices se cortaron en direccion mesiodistal y se prepararon para el microscopio electronico de barrido (MEB) con el fin de evaluar el barrillo dentinario y la presencia de restos; asi como mediante el analisis de espectroscopia de energia dispersiva (EDS) para evaluar componentes quimicos de la dentina despues del tratamiento. Los datos fueron sometidos a analisis estadistico (pruebas ANOVA de dos factores y de Tukey al 5 %). El analisis EDS mostro la presencia de componentes quimicos del material de relleno en las muestras de todos los grupos. Imagenes del MEB mostraron gran cantidad de tubulos dentinarios obliterados. El uso de la ultrasonido influyo en la eliminacion de algunos de los componentes de material de relleno (p <0,05), pero no permitio la limpieza total. Se concluyo que ninguna de las soluciones de irrigacion, asociadas o no a la utilizacion de los ultrasonidos fueron capaces de limpiar completamente el espacio para los postes.