Pre-eruptive intracoronal radiolucencies in permanent dentition of children in Tamil Nadu-A cross-sectional study.

BACKGROUND: Pre-eruptive intracoronal radiolucency (PEIR) poses a challenge to paediatric dentists as it cannot be clinically detected. AIM: To estimate the prevalence and coexisting factors of PEIR in permanent teeth of children and adolescents in western Tamil Nadu, India. DESIGN: This cross-sectional study assessed 5012 digital panoramic radiographs of children and adolescents below 14 years of age obtained from private digital imaging centers, dental clinics, and dental colleges located in five districts of western Tamil Nadu. The prevalence and PEIR and its coexisting factors were assessed by two independent calibrated investigators. Data were analyzed using the chi-square test. RESULTS: The subject prevalence and tooth prevalence of PEIR were estimated to be 3.2% and 0.4%, respectively. Maxillary canines and mandibular premolars were commonly involved. Majority of the lesions were limited to less than one-third of dentin thickness (74%) and distal aspect of the crown (45.1%). Ectopic positioning (9.3%) and dental caries in the preceding primary tooth (9.9%) were the most common coexisting factors. CONCLUSION: Pre-Eruptive Intracoronal Radiolucency defects were commonly seen in maxillary canines, mandibular premolars, and distal aspect of the crown involving less than one-third dentin thickness. Ectopic positioning and caries in primary teeth were commonly seen along with the PEIR defects.

Diagnosis of COVID-19 from Multimodal Imaging Data Using Optimized Deep Learning Techniques.

COVID-19 had a global impact, claiming many lives and disrupting healthcare systems even in many developed countries. Various mutations of the severe acute respiratory syndrome coronavirus-2, continue to be an impediment to early detection of this disease, which is vital for social well-being. Deep learning paradigm has been widely applied to investigate multimodal medical image data such as chest X-rays and CT scan images to aid in early detection and decision making about disease containment and treatment. Any method for reliable and accurate screening of COVID-19 infection would be beneficial for rapid detection as well as reducing direct virus exposure in healthcare professionals. Convolutional neural networks (CNN) have previously proven to be quite successful in the classification of medical images. A CNN is used in this study to suggest a deep learning classification method for detecting COVID-19 from chest X-ray images and CT scans. Samples from the Kaggle repository were collected to analyse model performance. Deep learning-based CNN models such as VGG-19, ResNet-50, Inception v3 and Xception models are optimized and compared by evaluating their accuracy after pre-processing the data. Because X-ray is a less expensive process than CT scan, chest X-ray images are considered to have a significant impact on COVID-19 screening. According to this work, chest X-rays outperform CT scans in terms of detection accuracy. The fine-tuned VGG-19 model detected COVID-19 with high accuracy-up to 94.17% for chest X-rays and 93% for CT scans. This work thereby concludes that VGG-19 was found to be the best suited model to detect COVID-19 and chest X-rays yield better accuracy than CT scans for the model.

Correction: Diagnosis of COVID­19 from Multimodal Imaging Data Using Optimized Deep Learning Techniques.

[This corrects the article DOI: 10.1007/s42979-022-01653-5.].

Preparation of gallotannin loaded chitosan/zinc oxide nanocomposite for photocatalytic degradation of organic dye and antibacterial applications.

Chitosan functionalization is a growing field of interest to enhance the unique characteristics of metal oxide nanoparticles. In this study, a facile synthesis method has been used to develop a gallotannin loaded chitosan/zinc oxide (CS/ZnO) nanocomposite. Initially, white color formation confirmed the formation, and physico-chemical natures of the prepared nanocomposite were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). Crystalline of CS amorphous phase and ZnO patterns were demonstrated by XRD. FTIR revealed the presence of CS and gallotannin bio-active groups in the formed nanocomposite. Electron microscopy study exhibited that the produced nanocomposite had an agglomerated sheets like morphology with an average size of 50-130 nm. Further, the produced nanocomposite was evaluated for methylene blue (MB) degradation activity from aqueous solution. After 30 min of irradiation, the efficiency of nanocomposite degradation was found to be 96.64 %. Moreover, prepared nanocomposite showed a potential and concentration-dependent antibacterial activity against S. aureus. In conclusion, our findings demonstrated that prepared nanocomposite can be used as an excellent photocatalyst as well as a bactericidal agent in industrial and clinical sectors.

Fabrication and Dosimetric Characteristics of Silicon Elastomer-Based Bolus Using External Beam Radiotherapy.

OBJECTIVE: A study on dosimetric characteristics of silicon elastomer-based bolus was carried out using a Linear accelerator (Varian - Unique Performance). The study is performed to know if the silicone elastomer based bolus can be used in the radiotherapy. A bolus is a tissue equivalent material used to provide uniform dose to the uneven surface contours. It is exposed during the radiation therapy and also provides maximum dose (dmax) to treat surface tumors in case of high energy photons like megavoltage therapy photons. It is used in the case of external beam radiation therapy. METHODS: In this study, the bolus was fabricated using PDMS substrate with a curing agent by the ratio of 10:1. The bolus was fabricated in two thicknesses 0.5cm and 1cm. The dosimetric characteristics like transmission factor, mass attenuation coefficient, durability, homogeneity, density test of the fabricated bolus were studied. RESULTS: The dosimetric characteristics of the silicone elastomer based bolus were studied over a period of one month by exposing it in a 6MV photon. The result of the study shows that the silicone elastomer based bolus fabricated, satisfies the dosimetric characteristics needed for a tissue equivalent bolus to be used in the radiation therapy. CONCLUSIONS: The fabricated bolus could increase the percentage surface dose, reduce skin-sparing effect, and protect OAR. The aim of this is to provide an adjustable, transparent, and easily fabricated, less expensive, nontoxic bolus which can be used in the radiotherapy.

Foreign Body Removal and Revascularization of Teeth with Periapical Radiolucency: 18 Months' Follow-Up.

Revascularization of the dental pulp is an emerging regenerative endodontic approach in which a new tissue is formed inside the root canal by induction of blood clot, allowing the continuation in the development of root. In this case report, the effective management of previously fractured immature tooth with the presence of foreign body (wire) inside the canal and radiographic periapical radiolucency had been described. A 17-year-old patient with immature fractured upper left lateral incisor with radiographic evidence of foreign body (wire) inside the canal was treated with removal of wire by H file followed by revascularization protocol that used working length determination, 5.25% sodium hypochlorite irrigation, intracanal medication with calcium hydroxide, final irrigation with 17% ethylenediaminetetraacetic acid and saline, induction of apical bleeding and blood clot formation, and coronal seal with mineral trioxide aggregate. Patient was recalled at every 3 months and response checked as the tooth remained asymptomatic. At 18 months' follow-up, intraoral periapical radiography radiograph was taken to evaluate the revascularization procedure. The periapical radiolucency was healed and root closure began to appear. Increased thickness of root width was also found. Although revascularization shows clinically acceptable results, care should be taken to achieve proper disinfection of canals and regular follow-up to improve long-term efficacy and new approaches.

Evaluation of Inhibitory Effect of Self-Etch Adhesives Incorporated with Proanthocyanidin on Cysteine Cathepsins Present in Dentin Hybrid Layer Using Gelatin Zymography: An In vitro Study.

AIM: The aim of the study is to evaluate the inhibitory effect of single-bottle and two-bottle self-etch adhesive system after surface pretreatment with 6.5% proanthocyanidin (PA) on cysteine cathepsins (CCs) present in dentin hybrid layer using gelatin zymography. MATERIALS AND METHODS: Thirty-five samples of dentin measuring 3 mm × 3 mm were obtained from 35 caries-free human third molars which were divided into seven groups. The bonded specimens were cut vertically into 1 mm thick adhesive/dentin interfaces with microtome and were pulverized into powder and subjected to zymography analysis for enzymatic activity. RESULTS: Group VI and VII which were positive control groups had shown thicker clear bands of 50 kDa. Group IV and V which had the administration of chlorhexidine showed thicker clear bands of 50 kDa which indicated slight activity of CCs. Group II in which PA used along with single-bottle system also showed thicker clear band of 59 kDa. CCs could be active due to strong acidic nature of monomer in this group. Group III in which PA used along with two bottle system had no band formation where there is crosslinking of catalytic and allosteric domains of enzymes by PA. CONCLUSION: Under the limitations of this study, PA proved as a non-specific natural inhibitor of CCs. Two-bottle system showed inhibition of CCs and single bottle system failed to inhibit their activity. Future research have to be done on the bond strength and durability of self-etch adhesives after using PA and its effect on long term survival of the restorations.