Quality of Root Canal Obturation Performed by Senior Undergraduate Dental Students

Introduction: There is a direct relationship between the quality of root canal obturation and success of endodontic therapy. The aim of the present study was to assess the quality of canal obturation performed by undergraduate dental students at the Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran. Materials and Methods: Records of 200 endodontically treated teeth from patients who were visited by undergraduate students between 2009 and 2010, at the Endodontic department, Faculty of Dentistry, Mashhad University of Medical Sciences, were randomly selected for evaluation. Periapical radiographs of all treated teeth were assessed in terms of canal obturation quality (i.e. adequate density and length). Statistical analysis of data was carried out using SPSS software and chi-square test. The Statistical significance level was set at P=0.05. Results: Forty-five percent of teeth fulfilled the criteria of an acceptable root canal obturation. Adequate length and density of root filling was found in 89% and 34% of teeth, respectively. There was a significant difference between maxillary and mandibular teeth regarding the length of root canal obturation (P=0.004). A significant difference was observed between molars and other tooth types. The frequency of root canals with an acceptable filling was significantly greater in the anterior teeth compared to premolars or molars. Conclusion: The technical quality of root canal treatment performed by undergraduate dental students was found to be less than ideal

Non-Surgical Root Canal Treatment of Dens Invaginatus 3 in a Maxillary Lateral Incisor

The aim of this case report was to describe the clinical management of an unusual dens invaginatus type 3. A case of dens invaginatus in a maxillary lateral incisor with a periapical lesion is reported. The patient presented with pain and localized swelling. Despite the complex anatomy and diagnosis of dens invaginatus, non-surgical root canal treatment was performed successfully. Key Learning Points:- Dens invaginatus may be presented in different forms, and the etiology of this phenomenon is not fully understood.- Due to abnormal anatomical configuration, dens invaginatus presents technical difficulties in its clinical management. - Non-surgical root canal treatment can be performed successfully

Influence of Two Preparation Techniques on Transportation of Simulated Type II Root Canals

Introduction: The purpose of this study was to evaluate the changes of canal configuration in simulated type II root canals that were instrumented by two different techniques using ProTaper Universal rotary files. Methods and Materials: Sixty simulated type II root canal in resin blocks were made and randomly divided into two groups. Pre and post-instrumentation images of resin blocks were prepared using stereomicroscope from three surfaces of blocks included two longitudinal section (mesiodistally and buccolingually), and one cross sectional surface. In the first group (G1) the straight canal was instrumented to the working length and the other canal was instrumented up to the area of canals junction. In second group (G2) both canals were instrumented to working length. The superimposed pre and post instrumentation images were assessed by the Adobe Photoshop software. The degree of transportation, centering ability, perimeter, surface and aspetic ratio (AR) in cross section and longitudinal section at apex, 3 mm and 5 mm above the apex, were measured. SPSS software, t-test and Mann-Whitney test were used for statistics analysis. Result: In mesiodistal direction, canal transportation was more (P=0.024) only in junction point in G2 which both canals were instrumented to working length. Also, surface changes were more significant (P=0.02) in G2 in cross sectional direction. The other parameter and also apical transportation had not significant difference in two groups. Conclusion: According to the results of this study, it can be concluded that both two preparation methods of type II canals can be used by rotary instruments.Keywords: Apical Transportation; Canal Transportation; Nickel Titanium; Root Canal Preparation; Root Canal Shap

Defect Detection and Classification in Sewer Pipeline Inspection Videos Using Deep Neural Networks

Sewer pipelines as a critical civil infrastructure become a concern for municipalities as they are getting near to the end of their service lives. Meanwhile, new environmental laws and regulations, city expansions, and budget constraints make it harder to maintain these networks. On the other hand, access and inspect sewer pipelines by human-entry based methods are problematic and risky. Current practice for sewer pipeline assessment uses various types of equipment to inspect the condition of pipelines. One of the most used technologies for sewer pipelines inspection is Closed Circuit Television (CCTV). However, application of CCTV method in extensive sewer networks involves certified operators to inspect hours of videos, which is time-consuming, labor-intensive, and error prone. The main objective of this research is to develop a framework for automated defect detection and classification in sewer CCTV inspection videos using computer vision techniques and deep neural networks. This study presents innovative algorithms to deal with the complexity of feature extraction and pattern recognition in sewer inspection videos due to lighting conditions, illumination variations, and unknown patterns of various sewer defects. Therefore, this research includes two main sub-models to first identify and localize anomalies in sewer inspection videos, and in the next phase, detect and classify the defects among the recognized anomalous frames. In the first phase, an innovative approach is proposed for identifying the frames with potential anomalies and localizing them in the pipe segment which is being inspected. The normal and anomalous frames are classified utilizing a one-class support vector machine (OC-SVM). The proposed approach employs 3D Scale Invariant Feature Transform (SIFT) to extract spatio-temporal features and capture scene dynamic statistics in sewer CCTV videos. The OC-SVM is trained by the frame-features which are considered normal, and the outliers to this model are considered abnormal frames. In the next step, the identified anomalous frames are located by recognizing the present text information in them using an end-to-end text recognition approach. The proposed localization approach is performed in two steps, first the text regions are detected using maximally stable extremal regions (MSER) algorithm, then the text characters are recognized using a convolutional neural network (CNN). The performance of the proposed model is tested using videos from real-world sewer inspection reports, where the accuracies of 95% and 86% were achieved for anomaly detection and frame localization, respectively. Identifying the anomalous frames and excluding the normal frames from further analysis could reduce the time and cost of detection. It also ensures the accuracy and quality of assessment by reducing the number of neglected anomalous frames caused by operator error. In the second phase, a defect detection framework is proposed to provide defect detection and classification among the identified anomalous frames. First, a deep Convolutional Neural Network (CNN) which is pre-trained using transfer learning, is used as a feature extractor. In the next step, the remaining convolutional layers of the constructed model are trained by the provided dataset from various types of sewer defects to detect and classify defects in the anomalous frames. The proposed methodology was validated by referencing the ground truth data of a dataset including four defects, and the mAP of 81.3% was achieved. It is expected that the developed model can help sewer inspectors in much faster and more accurate pipeline inspection. The whole framework would decrease the condition assessment time and increase the accuracy of sewer assessment reports

Centering ability and dentin removal of rotary systems in curved root canals

INTRODUCTION: The aim of this study was to compare centering ability and dentin removal of three rotary systems in curved root canals of extracted teeth. MATERIALS AND METHODS: Sixty root canals of mandibular first molars with curvatures ranging between 25-35o were divided into three groups of 20 teeth each. Based on pre-instrumentation radiographs that assessed the angle and the radius of canal curvatures, teeth with curvatures were equally spread between the three groups. The root canals were sectioned horizontally at two levels before preparation and then remounted onto the muffle. All root canals were prepared using a low-torque control motor with Mtwo or Medin or Race instruments. Cross sectional images were obtained before and after instrumentation. Cross-sectional area and centering ability were evaluated. The data were analyzed using the one-way ANOVA and Tukey tests. RESULTS: Neither instrument fracture nor permanent deformation occurred during preparations. The best centering ability was obtained by Mtwo instruments compare to Race and Medin instruments. In the coronal and middle sections, Mtwo removed less dentin than Race and Medin; while the difference in the apical section was not significant. CONCLUSION: Under the conditions of this study, the debridement of root canals was more conservative with Mtwo. The canals prepared with these instruments were better centered in all three regions of the root

Real-time, high frequency QRS electrocardiograph

Real time cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed in real time in a useful form on a computer screen or monitor. The monitor displays the high frequency data from the QRS complex in units of microvolts, juxtaposed with a display of conventional ECG data in units of millivolts or microvolts. The high frequency data are analyzed for their root mean square (RMS) voltage values and the discrete RMS values and related parameters are displayed in real time. The high frequency data from the QRS complex are analyzed with imbedded algorithms to determine the presence or absence of reduced amplitude zones, referred to herein as RAZs. RAZs are displayed as go, no-go signals on the computer monitor. The RMS and related values of the high frequency components are displayed as time varying signals, and the presence or absence of RAZs may be similarly displayed over time

Real-time, high frequency QRS electrocardiograph with reduced amplitude zone detection

Real time cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed in real time in a useful form on a computer screen or monitor. The monitor displays the high frequency data from the QRS complex in units of microvolts, juxtaposed with a display of conventional ECG data in units of millivolts or microvolts. The high frequency data are analyzed for their root mean square (RMS) voltage values and the discrete RMS values and related parameters are displayed in real time. The high frequency data from the QRS complex are analyzed with imbedded algorithms to determine the presence or absence of reduced amplitude zones, referred to herein as ''RAZs''. RAZs are displayed as ''go, no-go'' signals on the computer monitor. The RMS and related values of the high frequency components are displayed as time varying signals, and the presence or absence of RAZs may be similarly displayed over time

Diversificação de símile no estilo e estrutura de Gilani 'diwan A'li (suprema corte)

Simile has always been the subject of attention by poets and writers and it has a unique place. The uniqueness of this beautiful art attracts the imaginative element of poetry and readership, and the owners of style and writers that can't be easily remove this elegant and functional instrument. Poets and peoples use their efforts to bring their writings with a variety of similes. A poet is capable that use these imaginative designs in the most beautiful way. In this article, we examine the types of simile in the poem of Gilani Supreme Court. The provided table helps the reader to understand hidden sides of the poet's thoughts. Among the used similes, topic is the praise, Image is around subjects. A'li used composite, sensory, wisdom simile and the supposed syntax has the highest repetition among the poet's poetry. A'li used simile more than any other instrument in his poem.El símil siempre ha sido el tema de atención de poetas y escritores y tiene un lugar único. La singularidad de este bello arte atrae el elemento imaginativo de la poesía y los lectores, y los propietarios de estilo y escritores que no pueden eliminar fácilmente este instrumento elegante y funcional. Los poetas y los pueblos usan sus esfuerzos para llevar sus escritos con una variedad de símiles. Un poeta es capaz de utilizar estos diseños imaginativos de la manera más bella. En este artículo, examinamos los tipos de símil en el poema de la Corte Suprema de Gilani. La tabla proporcionada ayuda al lector a comprender los lados ocultos de los pensamientos del poeta. Entre los símiles usados, el tema es el elogio, la imagen está alrededor de los sujetos. A'li utilizó un símil compuesto, sensorial, de sabiduría y la supuesta sintaxis tiene la mayor repetición entre la poesía del poeta. A'li usó símil más que cualquier otro instrumento en su poema.Simile sempre foi objeto de atenção de poetas e escritores e tem um lugar único. A singularidade desta bela arte atrai o elemento imaginativo de poesia e leitura, e os donos de estilo e escritores que não podem facilmente remover este instrumento elegante e funcional. Poetas e povos usam seus esforços para trazer seus escritos com uma variedade de símiles. Um poeta é capaz de usar esses desenhos imaginativos da maneira mais bonita. Neste artigo, examinamos os tipos de símile no poema da Suprema Corte de Gilani.  A tabela fornecida ajuda o leitor a entender os lados ocultos dos pensamentos do poeta. Entre os símiles usados, tópico é o elogio, Imag em é em torno de assuntos. A'li usou compósitos, sensorial, simile de sabedoria e a suposta sintaxe tem a mais alta repetição entre a poesia do poeta. A'li usou símile mais do que qualquer outro instrumento em seu poema

Sealing Ability of Orthograde MTA and CEM Cement in Apically Resected Roots Using Bacterial Leakage Method

Introduction: The aim of this in vitro study was to determine the sealing ability of orthograde ProRoot mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM) cement as root-end filling materials. Materials and Methods: Fifty four extracted single-rooted human teeth were used. The samples were randomly divided into 3 experimental groups. In group A and B, 4 mm of WMTA and CEM cement were placed in an orthograde manner and 3 mm of apices were resected after 24 hours. In group C the apical 3 mm of each root was resected and the root-end prepared with ultrasonic tips to a depth of 3 mm and subsequently, then filled with MTA. The apical sealing ability was performed with bacterial leakage method. Statistical analysis was carried out with Chi-square test. Results: There were no significant differences in the extent of bacterial leakage between the three experimental groups (P>0.05). Conclusion: Based on the limitations of this in vitro study, we concluded that MTA and CEM cement can be placed in an orthograde manner when there is a potential need for root-end surgery