Root Canal Morphology of Mandibular Primary Molars: A Micro-CT Study

Objectives: Frequency of typical and non-typical root and canal morphology of primary teeth, which in clinical practice cannot be detected using 2D radiographic images, should be known by clinicians to decrease failures arising from complexity of root canal morphologies. The aim of this in vitro study was to evaluate morphologic variations in mandibular primary molars’ root canal systems. Materials and Methods: Primary mandibular 1st (n=17) and 2nd (n=33) molars were scanned using micro-CT. 3D root models were obtained and root canal morphologies were evaluated according to a modified Vertucci classification. Type 1 and Type 4 canal morphologies were evaluated as ‘normal’ and all other types and ‘non-typical’ canal morphology were evaluated as ‘abnormal’ root canal morphology. Results: Most common root canal morphology among mandibular primary 1st molars were Vertucci Type 4 morphology for both mesial and distal roots (47% and 41.2% respectively), and non-typical morphology for both the mesial and distal roots (45.7% and 21.2% respectively) of mandibular primary 2nd molars. Conclusions: Wide range of morphologic variations and frequency of non-typical morphology could be seen especially among mandibular primary 2nd molars and use of disinfectant irrigants and root canal fillings with high antibacterial efficacies are important in order to decrease failures arising from these inaccessible areas

The effect of different irrigation protocols on smear layer removal in root canals of primary teeth: a SEM study

Objective: The purpose of this study was to compare the efficacy of different irrigation protocols on smear layer removal in root canals of primary teeth by scanning electron microscopy (SEM). Material and methods: The study was conducted with 40 extracted maxillary primary incisor teeth divided into four groups (n = 10) as 1% sodium hypochlorite (NaOCl), 10% ethylenediaminetetraacetic acid (EDTA)+1% NaOCl, 6% citric acid (CA)+1% NaOCl, and 0.9% physiological saline (PS). After the irrigation procedures, root canal walls were examined by SEM and the efficacies of irrigation solutions in smear layer removal were scored and compared. Data were analyzed using Kruskal-Wallis, Friedman and Siegel Castellan tests. Results: The smear layer removal was found to be statistically more effective in groups of 10% EDTA + 1% NaOCl and 6% CA + 1% NaOCl when compared with the other groups (p < .05). Smear removal efficacy was statistically significantly higher in coronal and medium thirds when compared with the apical regions in the experimental groups. Conclusions: It was concluded that 10% EDTA + 1% NaOCl and 6% CA + 1% NaOCl could be alternative irrigation protocols regarding smear layer removal. However, due to the absence of erosive dentinal changes, it might be suggested that using 6% CA + 1% NaOCl can be recommended compared to 10% EDTA + 1% NaOCl in primary root canals

The effects of various irrigation protocols on root canal wall adaptation and apical microleakage in primary teeth

Objective: The objective of this study is to evaluate the wall adaptation and apical microleakage values following the application of various irrigation protocols in primary teeth. Material and methods: For the two parts of the study, extracted upper incisor primary teeth were randomly included to the 1% sodium hypochlorite (NaOCl), 10% ethylenediaminetetraacetic acid (EDTA)+1% NaOCl, 6% citric acid (CA)+1% NaOCl and 0.9% physiological saline (PS) groups. Canal wall adaptation and apical microleakage were assessed by scanning electron microscopy (SEM) and stereomicroscope, respectively. Results: 6% CA + 1% NaOCl group was found to be the most successful irrigation protocol in providing strong canal wall adaptation and less apical microleakage, followed by 10% EDTA +1% NaOCl. 6% CA +1% NaOCl was significantly superior regarding apical microleakage (p < .05). Conclusions: Due to the ability to provide appropriate changes in the root canal walls to make a well-adapted and leak-proof canal filling, 6% CA + 1% NaOCl can be recommended as an irrigation protocol in primary teeth

Portable Plasmonic Biosensor for Virus Detection in Resource-Poor Settings

Early detection and diagnosis of infectious diseases caused by viruses is crucial for public and global health. Due to their high sensitivity, current technologies such as enzyme-linked immunosorbent assays (ELISA), polymerase chain reactions (PCR) and cell cultures are employed to diagnose viral infections. However, these technologies require long and expensive experiment processes, bulky instrumentations and laboratory professionals. Hence, their application in point- of-care diagnostics for viral diseases is not feasible especially for underdeveloped countries where there is an absence of medical infrastructure and healthcare professionals. Therefore, the development of highly sensitive, user-friendly, field-deployable point-of-care devices with strong specificity for rapid and accurate diagnosis of viral diseases in resource-poor settings is crucial in order to prevent pandemics related to virus-borne diseases. In this study, a lightweight and field- portable biosensor that employs a plasmonic chip based on nanohole arrays integrated to a lens free-imaging framework for label-free detection of viruses in field-settings is introduced. In order to monitor diffraction field patterns of nanohole arrays under the uniform illumination of an LED (light-emitting diode) source which is spectrally tuned to the plasmonic mode supported by the nanohole arrays, a CMOS (complementary metal–oxide–semiconductor) camera with high quantum efficiency in the spectral window of interest is utilized. We could successfully demonstrate the label-free detection of H1N1 viruses, such as swine flu, with medically relevant concentrations to demonstrate the applicability of our biosensor for virus detection. Additionally, to prepare the surface of the plasmonic chip for analyte binding, such as virus-antibody binding, we developed an affordable, easy-to-use sample preparation kit. We also developed a user-friendly PythonTM – based graphical user interface (GUI) that gives end users direct access to the biosensor hardware, allows them to capture and process diffraction field images, and provides virus information. Our platform could yield a LOD as low as 103 TCID50/mL by employing highly sensitive nanohole arrays and a lens free-imaging framework. Our biosensor could be a very strong candidate for diagnostic applications in resource-poor settings since it provides accurate and rapid sensing information in a handheld platform that is only 70 g and 12 cm tall, without the need for bulky and expensive instrumentation. Since the basis of our detection method is usage of antibodies, it could be quickly adapted by simply coating the plasmonic chip surface with an antibody possessing affinity to the virus type of interest to detect different viral diseases such as COVID-19 or influenza. Therefore, our biosensor may be an important asset to prevent the spread of diseases before turning into a pandemic by isolating patients from the population.</p