Perceptions and challenges of online teaching and learning amidst the COVID-19 pandemic in India: a cross-sectional study with dental students and teachers.

BACKGROUND: Online education has emerged as a crucial tool for imparting knowledge and skills to students in the twenty-first century, especially in developing nations like India, which previously relied heavily on traditional teaching methods. METHODS: This study delved into the perceptions and challenges experienced by students and teachers in the context of online education during the COVID-19 pandemic. Data were collected from a sample of 491 dental students and 132 teachers utilizing a cross-sectional research design and an online-validated survey questionnaire. RESULTS: The study's findings revealed significant insights. Internet accessibility emerged as a major impediment for students, with online instruction proving more effective for theoretical subjects compared to practical ones. Although most teachers expressed comfort with online teaching, they highlighted the absence of classroom interaction as a significant challenge. CONCLUSION: This study comprehensively examines the perspectives of both students and teachers regarding online education during the pandemic. The results carry substantial implications for the academic community, underscoring the need to address internet access issues and explore ways to enhance engagement and interaction in online learning environments.

Evaluation of Microleakage of Nanoparticle-incorporated Cyanoacrylate Root Canal Sealer Using the Radioisotopic Method: An In Vitro Study.

AIM OF THE STUDY: The study aimed to assess the microleakage of nanoparticle-based (NPB) cyanoacrylate sealer and epoxy resin-based (ERB) sealer using radioisotope method and confocal laser scanning microscopy (CLSM). MATERIALS AND METHODS: A total of 100 single-rooted teeth were collected; specimens were accessed, instrumented, and irrigated, and randomly distributed into 4 groups of 25 samples each: Group I: Positive control, group II: Negative control, group III: Obturated with NPB sealer, and group IV: Obturated with ERB sealer. All samples were immersed in 99mTc pertechnetate solution, for 3 hours after which radioactivity was estimated under a Gamma camera. The radioactivity released by specimens before and after nail varnish removal was statistically analyzed. After 2 weeks, the same samples were used for CLSM analysis. The sealer tubular penetration depth was measured at the deepest level for each group using ZEN lite 2012. Data collected was statistically evaluated. RESULTS: The amount of radioactivity observed at first in group III and group IV was 194.76 and 599.12 units, respectively, with p-value < 0.001, indicating significant interaction, and after nail varnish removal, it was 89.68 and 468.44 units, respectively, with a p-value < 0.001; again, indicating statistical significance. Hence, the radioactivity of NPB sealer was found to be lower than ERB sealer in both cases, indicating better sealing of the former. The photomicrographs show that mean value of dye penetration in NPB sealer in first, second, and third segment from apex was 85.06, 75.73, and 66.09, respectively; while in the case of ERB sealer, those were 597.28, 461.17, and 195.68, respectively; with p-value < 0.001; signifying that NPB sealer exhibited higher resistance to microleakage than ERB sealer. CONCLUSION: The NPB sealer can become a potential root canal sealer in future endodontics due to superior physiochemical properties attributed to the cyanoacrylate and incorporated nanoparticles. CLINICAL SIGNIFICANCE: The study clinically signifies that we can equally use the radioisotopic method along with confocal method while conducting the microleakage studies. In addition, NPB sealer can be an emerging replacement with better properties than gold standard root canal sealers for clinical use. How to cite this article: Shetty C, Qaiser S, Shetty A, et al. Evaluation of Microleakage of Nanoparticle-incorporated Cyanoacrylate Root Canal Sealer Using the Radioisotopic Method: An In Vitro Study. J Contemp Dent Pract 2024;25(4):335-341.

Intraday dynamic rescheduling under patient no-shows.

Patient no-shows are a major source of uncertainty for outpatient clinics. A common approach to hedge against the effect of no-shows is to overbook. The trade-off between patient's waiting costs and provider idling/overtime costs determines the optimal level of overbooking. Existing work on appointment scheduling assumes that appointment times cannot be updated once they have been assigned. However, advances in communication technology and the adoption of online (as opposed to in-person) appointments make it possible for appointments to be flexible. In this paper, we describe an intraday dynamic rescheduling model that adjusts upcoming appointments based on observed no-shows. We formulate the problem as a Markov Decision Process in order to compute the optimal pre-day schedule and the optimal policy to update the schedule for every scenario of no-shows. We also propose an alternative formulation based on the idea of 'atomic' actions that allows us to apply a shortest path algorithm to solve for the optimal policy more efficiently. Based on a numerical study using parameter estimates from existing literature, we find that intraday dynamic rescheduling can reduce expected cost by 15% compared to static scheduling.

Ozonated water as an irrigant in disinfecting root canal systems - a systematic review.

Aim To evaluate the efficacy of ozonated water as an irrigant in disinfection of the root canal system.Materials and methods This systematic review was conducted according to PRISMA guidelines and methodological studies were assessed through the Cochrane Risk of Bias tool. All studies on extracted human teeth using ozonated water were considered for the study, whereas ex vivo studies, studies on animal dentition and studies which were published in languages other than English were excluded from the study. The search was carried out on various databases such as PubMed, Google Scholar and ScienceDirect within the last 15 years. The assessment of quality of the studies was performed under the following: 1) size of sample; 2) control group; 3) standardisation of procedure; 4) statistical analysis performed; 5) risk of bias.Results There were a total of 154 study results, out of which duplicates and full-text analysis were excluded. A total of seven studies were included in the systematic review. The results in one study by Cardoso et al. showed ozonated water was better at reducing microbial counts, while two other studies demonstrated the difference in reducing microbial counts when comparing ozonated water against other irrigants. The remaining four studies concluded that ozonated water did not perform better as compared to the other irrigants such as sodium hypochlorite and chlorhexidine.Discussion It could be concluded that ozonated water is not a better disinfecting irrigant than sodium hypochlorite and chlorhexidine in the disinfection of the root canal system; however, it had an almost comparable level of disinfection.

Knowledge, attitude and practice of dental students and practitioners during the early days of COVID-19 pandemic in India: A cross-sectional study.

AIM: The novel coronavirus disease-2019 (COVID-19) is a major health problem and has affected innumerable people around the world. The current online-based study was conducted to assess the knowledge, attitude and practice (KAP) of dental students and professionals during the early days of lockdown in India from 2 April to 1 May 2020. METHODOLOGY: An online-based cross-sectional study was undertaken through WhatsApp messenger and e-mail groups among dental students and professionals. The KAP on COVID-19 was ascertained using an investigator designed and validated questionnaire. The results were stratified based on student vs professionals. The data were expressed as frequency and percentage analysed using the chi-square/Fishers exact test using IBM version 17. A probability value of <.05 was considered significant. RESULTS: A total of 287 complete responses from the dental students and professionals were received. The results indicated that the knowledge of both dental students and professionals were good and that the attitude and practice were in accordance with good clinical practice. No significant differences were found within the domains of KAP scores among the dental students and practitioners indicating that the study participants were abreast with the recent advances. CONCLUSION: The results of this study conducted during the early stage of the lockdown indicated that the dental students and professionals who had filled the questionnaire had very good knowledge of coronavirus and COVID-19. CLINICAL IMPLICATIONS: The results of the study indicate that the volunteers had good knowledge, attitude and self-care practice, which are necessary in preventing the spread of COVID-19. It is anticipated that detailed hands-on training in practical aspects of good clinical practice with protective gears will help students and professionals perform the necessary dental procedures in accordance with the guidelines set by Centers for Disease Control and Prevention and World Health Organization.

Three-dimensional qualitative and quantitative analyses of the effect of periradicular lesions on the outcome of regenerative endodontic procedures: A prospective clinical study.

OBJECTIVES: Qualitative and quantitative evaluation of the outcomes of regenerative endodontic procedure (REP) on human immature necrotic teeth with apical periodontitis using cone-beam computed tomography (CBCT) MATERIALS AND METHODS: Immature permanent teeth (n = 50) with necrotic pulp and periradicular pathosis were treated with a cell-homing concept-based REP. Following the procedure, a limited field-of-view CBCT scan was obtained. At each recall session (6, 12, 18 months), clinical tests were performed, and a digital periapical radiograph was taken. When significant radiographic changes were evident in the follow-up, a final CBCT scan was taken for qualitative and quantitative assessment. These initial and follow-up CBCT scans were assessed for quantification of changes in root length, pulp space diameter and periradicular lesion size. The data were statistically analysed using t test, one-way ANOVA, post hoc test and paired t test (P = 0.05). RESULTS: Of the teeth, 94.6% were clinically successful based on the lack or regression of signs and symptoms after 48 months follow-up. REP resulted in a statistically significant increase in root length, decrease in pulp space diameter and periradicular radiolucency (P < 0.05). CBCT images illustrated various patterns of root maturation including an increased thickening of the canal walls and continued root maturation (37.1%), continued root development with the apical foramen remaining open (57.1%), severe calcification (obliteration) of the canal space (2.9%) and hard tissue barrier formation in the canal space between the coronal plug and the root apex (2.9%). CONCLUSION: This study highlighted that the expected outcome of radiographic root development was less predictable when immature permanent teeth with periradicular pathosis were treated with REP. CLINICAL RELEVANCE: The size and extent (expansion/destruction of the cortical plate) of periradicular lesions and abscesses influence the outcome of REP. These factors must be taken into consideration during treatment planning.

Outcomes of unselected patients with metastatic clear-cell renal cell carcinoma treated with first-line pazopanib therapy followed by vascular endothelial growth factor receptor tyrosine kinase inhibitors or mammalian target of rapamycin inhibitors: a single institution experience.

OBJECTIVE: To explore the efficacy and safety of pazopanib in a 'real-world' setting in unselected patients, as data regarding unselected patients with metastatic clear-cell renal cell carcinoma (ccRCC) treated with first-line pazopanib are limited. PATIENTS AND METHODS: We reviewed records of patients with metastatic ccRCC treated with first-line pazopanib from 1 November 2009 through to 1 November 2012. Cox models were fitted to evaluate the association of progression-free survival (PFS) and overall survival (OS) with patient co-variables. RESULTS: In all, 88 patients were identified; 74 were evaluable for response: two (3%) had a complete response, 27 (36%) a partial response, 36 (49%) had stable disease and nine (12%) had progressive disease. The median PFS was 13.7 months [95% confidence interval (CI) 8.7-18.3]. PFS was correlated with a Karnofsky Performance Status score of <80 [hazard ratio (HR) 3.26, P < 0.001] and serum lactate dehydrogenase of >1.5 × upper limit of normal (HR 3.25, P = 0.014). The median OS was 29.1 months (95% CI 20.2-not reached). The OS was correlated with brain metastasis (HR 2.55, P = 0.009), neutrophilia (HR 1.179, P = 0.018), and anaemia (HR 3.51, P < 0.001). There were no treatment-related deaths. In all, 53 patients received second-line therapy [vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKI) in 22 patients, mammalian target of rapamycin inhibitors (mTORi) in 22 patients, and other therapy in nine patients]; the median PFS was 8.6 months (95% CI 3.3-25.7) with VEGFR-TKI and 5 months (95% CI 3.5-15.2) with mTORi (P = 0.41); the median OS was 19.9 months (95% CI 12.9-not reached) and 14.2 months (95% CI 8.1-not reached), from initiation of second-line VEGFR-TKI or mTORi, respectively (P = 0.37). CONCLUSIONS: In this retrospective study, first-line pazopanib confirmed its efficacy in metastatic ccRCC. Trends for longer PFS and OS were seen with VEGFR-TKI compared with mTORi after first-line pazopanib.

Bone marrow necrosis in acute leukemia: Clinical characteristic and outcome.

Bone marrow necrosis (BMN) is characterized by infarction of the medullary stroma, leading to marrow necrosis with preserved cortical bone. In reported small series, BMN in hematological malignancies is associated with poor prognosis. We sought to find the impact of BMN on clinical outcome in a relatively larger cohort of patients with acute leukemias. Overall we evaluated 1,691 patients; 1,051 with acute myeloid leukemia (AML) and 640 with acute lymphocytic leukemia referred to our institution between 2002 and 2013. Patients with AML and acute lymphoblastic leukemia (ALL) were evaluated separately to determine the incidence of BMN, associated clinical features and its prognostic significance. At initial diagnosis, BMN was observed in 25 (2.4%) patients with AML and 20 (3.2%) patients with ALL. In AML, BMN was significantly associated with French-American-British AML M5 morphology (32% vs. 10%, P = 0.002). The complete remission (CR) rate in AML with and without BMN was 32% and 59% respectively (P = 0.008). Likewise, CR rate in ALL with BMN was also inferior, 70% vs. 92% (P = 0.005). The median overall survival (OS) in AML with BMN was significantly poorer, 3.7 months compared to 14 months without BMN (P = 0.003). Similarly, the median OS in ALL with and without BMN was 61.7 and 72 months respectively (P = 0.33). BMN is not a rare entity in AML and ALL, but is infrequent. BMN in AML and in ALL is suggestive of inferior response and poor prognosis.

Assessment of sealing efficacy, radiopacity, and surface topography of a bioinspired polymer for perforation repair.

Background: Root perforation repair presents a significant challenge in dentistry due to inherent limitations of existing materials. This study explored the potential of a novel polydopamine-based composite as a root repair material by evaluating its sealing efficacy, radiopacity, and surface topography. Methods: Confocal microscopy assessed sealing ability, comparing the polydopamine-based composite to the gold standard, mineral trioxide aggregate (MTA). Radiopacity was evaluated using the aluminium step wedge technique conforming to ISO standards. Surface roughness analysis utilized atomic force microscopy (AFM), while field emission scanning electron microscopy (FESEM) visualized morphology. Results: The polydopamine-based composite exhibited significantly superior sealing efficacy compared to MTA (P < 0.001). Radiopacity reached 3 mm aluminium equivalent, exceeding minimum clinical requirements. AFM analysis revealed a smooth surface topography, and FESEM confirmed successful composite synthesis. Conclusion: This study demonstrates promising properties of the polydopamine-based composite for root perforation repair, including superior sealing efficacy, clinically relevant radiopacity, and smooth surface topography. Further investigation is warranted to assess its clinical viability and potential translation to endodontic practice.

Impact of molecular alterations and targeted therapy in appendiceal adenocarcinomas.

UNLABELLED: Appendiceal adenocarcinomas (AAs) are rare and this has limited their molecular understanding. The purpose of our study was to characterize the molecular profile of AA and explore the role of targeted therapy against cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR). PATIENTS AND METHODS: We performed a retrospective review of 607 patients with AA at a single institution. A total of 149 patients underwent molecular testing for at least one of the following: activating mutations in KRAS, BRAF, cKIT, EGFR, or PI3K; protein expression of c-KIT or COX-2; or microsatellite instability (MSI) status by immunohistochemistry. Kaplan-Meier product limit method and log-rank test were used to estimate overall survival (OS) and to determine associations among OS, COX-2 expression, KRAS mutations, and other characteristics. RESULTS: Age, grade, stage, signet ring cells, mucinous histology, and completeness of cytoreduction score correlated with survival outcomes. COX-2 expression, KRAS, PI3K, and BRAF mutations were seen in 61%, 55%, 17%, and 4% of patients, respectively. High MSI was seen in 6% of patients. KRAS mutation was strongly associated with well differentiated or moderately differentiated AA (p < .01). COX-2 expression (p = .33) and the presence of KRAS mutation (p = .91) had no impact on OS. The use of celecoxib in patients whose tumors expressed COX-2 (p = .84) and the use of cetuximab or panitumumab in patients with KRAS wild-type tumors (p = .83) also had no impact on OS. CONCLUSION: In this cohort, we demonstrated that COX-2 expression and KRAS mutations were frequently seen in AA, although neither exhibited any prognostic significance. MSI was infrequent in AA. Targeted therapy against COX-2 and EGFR appeared to provide no clinical benefit. Well and moderately differentiated AA were molecularly distinct from poorly differentiated AA.

Palmitate-derivatized human IL-2: a potential anticancer immunotherapeutic of low systemic toxicity.

PURPOSE AND EXPERIMENTAL DESIGN: Recombinant human IL-2 (rhIL-2) is a potent cytokine and FDA-approved anticancer drug. However, its clinical use has been limited by severe toxicity, associated primarily with systemic administration with excess protein distributing freely throughout the body. We hypothesized that rhIL-2 in alternate forms permitting more restricted localization may exert stronger antitumor efficacy and less toxicity. Here, we have tested the utility of palmitate-derivatized rhIL-2. rhIL-2 was reacted with N-hydroxysuccinimide palmitate ester. The resultant lipidated rhIL-2 (pIL-2), when mixed with cells, could spontaneously transfer from solution to cell surfaces. Next, anticancer efficacy of pIL-2 was assessed in two modalities. For adoptive T cell therapy, antitumor cytotoxic T cells (CTLs) were protein transferred ("painted") with pIL-2 and injected into mice bearing lymphoma. For in situ therapy, pIL-2 was injected intratumorally into mice bearing melanoma. Tumor growth and IL-2-associated toxicity were determined. RESULTS: In the lymphoma model, painting of the antitumor CTLs with pIL-2 markedly increased their viability and titer. In the melanoma model, intratumoral injection of pIL-2, but not rhIL-2, increased the number of activated CD8(+) T cells (IFN-γ(+)) in the spleen, reduced lung metastasis and prolonged the survival of treated mice. Moreover, while repeated intratumoral injection of rhIL-2 at an excessively high dose (10 injections of 10,000 IU/mouse) caused marked vascular leakage syndrome, the same regimen using pIL-2 caused no detectable toxicity. CONCLUSIONS: Transferring spontaneously from solution to cell surfaces, pIL-2 may bypass the current limitations of rhIL-2 and, thus, serve as a more effective and tolerable anticancer drug.

Urinary exosomal miRNA signature of IgA nephropathy: a case-control study.

IgA nephropathy is the most common primary glomerulonephritis worldwide and can progress to end-stage kidney disease (ESKD). The current "gold standard" for diagnosis is kidney biopsy, which is invasive and associated with morbidity. miRNAs are small, non-coding endogenous RNA that may serve as non-invasive biomarkers, and that are found in urinary exosomes. Thus far, there is a paucity of studies of the miRNA profile for the diagnosis of IgA nephropathy. Hence, we aimed to study the urinary exosomal miRNA signature of Indian patients with IgA nephropathy. Fifty biopsy-proven IgA nephropathy patients, 50 healthy controls and 25 patients with ESKD (IgA nephropathy) were recruited over 2 years (2020-2022). Urinary exosomes were isolated from which miRNA was extracted . Analysis of urinary exosomal miRNA was done using the digital multiplexed nCounter® human v3 miRNA Expression Assay which contains 799 unique miRNA barcodes. Candidate miRNAs were identified using Lasso regression and consensus clustering. The mean age of IgA nephropathy patients was 36.32 ± 3.067 years, mean creatinine was 2.26 ± 0.318 mg/dl and mean proteinuria was 2.69 ± 0.64 g/day. Compared to healthy controls, the majority (N = 150) of miRNAs were significantly downregulated. Five candidate miRNAs (hsa.miR.146b.3p, hsa.miR.599, hsa.miR.4532, hsa.miR.664b.5p and hsa.miR.221.5p) were able to differentiate between IgA nephropathy cases and controls (AUC > 0.90); the presence of all 5 was associated with 100% specificity and sensitivity for diagnosing IgA nephropathy cases. This study of Indian patients identified that there was a significant difference in the urinary exosomal miRNA profile between IgA nephropathy cases and healthy controls, suggesting that miRNAs may be valuable in the non-invasive diagnosis of IgA nephropathy.

Investigation of the hydration process and biological activity of a novel nanosilver incorporated dicalcium silicate based retrograde filling material.

Background: Although several materials have been used for retrograde filling following apical surgeries, there is no consensus on a single best material. Tricalcium silicate-based types of cement have been developed as root-end filling materials mainly due to tricalcium silicate's hydraulic properties. However, its unfavorable setting characteristics and minimal antimicrobial properties have necessitated the introduction of new additives into the existing commercially available materials. To design an affordable product based on a dicalcium silicate with a shorter set time, minimal cytotoxic complications, and enhanced antibacterial activity, we developed a new endodontic cement from pure raw materials, intending to satisfy the prerequisites of ideal retrograde material. Methods: The composition of the experimental calcium silicate-based cement included the addition of calcium chloride and silver nanoparticles in varying concentrations. Structural characterization was carried out using energy dispersive analysis by X-rays using scanning electron microscope (EDAX SEM) and hydration characteristics were performed using an X-ray diffractometer (XRD). The experimental material was further evaluated for biocompatibility using MTT ([3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide)assay and antibacterial activity was evaluated using an agar diffusion test against Enterococcus faecalis. Results: The structural characterization and hydration characteristics revealed that the experimental cement was dicalcium silicate based with favorable biocompatibility and enhanced antibacterial activity. Tricalcium silicate based mineral trioxide aggregate (MTA) also had favourable biocompatibility, however, its antibacterial activity was significantly decreased when compared to the novel cement. Conclusion: All hydraulic cements that are available in the dental market are predominantly tricalcium silicate-based materials. There has been no evidence in the literature to date wherein it has been explored whether a dicalcium silicate-based hydraulic cement can solely be used in root-end cavities. The findings of the study revealed a dicalcium silicate based retrograde filling material with favourable biocompatibility exhibited immediately as well as in the set samples. Incorporation of silver nanoparticles boosted the antibacterial activity when compared to that of ProRoot MTA. This material could potentially reinstate the usual hype created with tricalcium silicate types of cement since dicalcium silicate cements also exhibit similar properties.

Adagrasib in Advanced Solid Tumors Harboring a KRASG12C Mutation.

PURPOSE: Adagrasib, a KRASG12C inhibitor, has demonstrated clinical activity in patients with KRASG12C-mutated non-small-cell lung cancer (NSCLC) and colorectal cancer (CRC). KRASG12C mutations occur rarely in other solid tumor types. We report evaluation of the clinical activity and safety of adagrasib in patients with other solid tumors harboring a KRASG12C mutation. METHODS: In this phase II cohort of the KRYSTAL-1 study (ClinicalTrials.gov identifier: NCT03785249; phase Ib cohort), we evaluated adagrasib (600 mg orally twice daily) in patients with KRASG12C-mutated advanced solid tumors (excluding NSCLC and CRC). The primary end point was objective response rate. Secondary end points included duration of response, progression-free survival (PFS), overall survival, and safety. RESULTS: As of October 1, 2022, 64 patients with KRASG12C-mutated solid tumors were enrolled and 63 patients treated (median follow-up, 16.8 months). The median number of prior lines of systemic therapy was 2. Among 57 patients with measurable disease at baseline, objective responses were observed in 20 (35.1%) patients (all partial responses), including 7/21 (33.3%) responses in pancreatic and 5/12 (41.7%) in biliary tract cancers. The median duration of response was 5.3 months (95% CI, 2.8 to 7.3) and median PFS was 7.4 months (95% CI, 5.3 to 8.6). Treatment-related adverse events (TRAEs) of any grade were observed in 96.8% of patients and grade 3-4 in 27.0%; there were no grade 5 TRAEs. TRAEs did not lead to treatment discontinuation in any patients. CONCLUSION: Adagrasib demonstrates encouraging clinical activity and is well tolerated in this rare cohort of pretreated patients with KRASG12C-mutated solid tumors.

Comparative characterization and analysis of telomere length in stem cells derived from deciduous and permanent teeth.

Background: Understanding the influence of age on growth kinetics and telomere length in dental stem cells is essential for the successful development of cell therapies. Hence, the present study compared the basic cellular and phenotypical characteristics of stem cells from human exfoliated deciduous teeth (SHEDs) and dental pulp stem cells (DPSCs) of permanent teeth and their telomere lengths using quantitative real-time polymerase chain reaction. Materials and Methods: The study is an in vitro original research article. Primary cultures of SHED and DPSCs (n = 6 each) were successfully established in vitro, and the parameters analyzed were the morphology, viability, proliferation rate, population doubling time (PDT), phenotypic markers expression, and the relative telomere lengths. Data were analyzed by analysis of variance and P < 0.05 was considered statistically significant. Results: SHED and DPSCs exhibited a small spindle-shaped fibroblast-like morphology with >90% viability. The proliferation assay showed that the cells had a typical growth pattern. The PDT values of SHED and DPSCs were 29.03 ± 9.71 h and 32.05 ± 9.76 h, respectively. Both cells were positive for surface markers CD29, CD44, and CD90. However, they were negative for CD45 and human leukocyte antigen DR. Although the differences in relative telomere lengths between the individual cell lines of SHED and DPSCs were observed, no significant (P > 0.05) variations were found for the mean T/S ratios of both the cells. Conclusion: SHED and DPSCs displayed similar morphology, proliferation rates, and phenotypic features. The relative telomere lengths were slightly shorter in DPSCs than SHED, but the values were not significantly different. Thus, SHED and DPSCs can be considered as recognized sources for regenerative applications in dentistry.

Apprehensions and Optimism among Dental Professionals during the COVID-19 Pandemic-A Nationwide Cross-Sectional Evaluation.

Globally, the pandemic of the coronavirus disease, which started in Wuhan, China, has become a major issue for public health. The COVID-19 epidemic notably causes health professionals to experience significantly more emotional stress than the general populace. The present study proposes to investigate the fear aspect in dentists in the initiation of clinical practice during these times. An online cross-sectional study was conducted among dental practitioners based on a pre-validated questionnaire. The data were expressed as frequency and percentage analyzed using the chi-square test using SPSS version 25. The data was obtained from 271 participants, where clinical practice after the first wave was mostly by freelancers (p-value = 0.01); most of whom were married (p-value = 0.065); 19.1% attached to institutes did not have changes in earnings; 28.1% of private practitioners had less than 10% reduction in cases. A total of 62% of private practitioners are concerned about the vaccine's preventative effects (p-value = 0.026), and 57% of private practitioners worry about being sued for the delay in treatment (p-value = 0.036). Only 33.1% of employees in institutions worry that becoming sick could endanger their family. As dentists continue to work their way through this pandemic, these pressures only occasionally have an impact on them. According to the researchers, this is the first study that has captured the anxiety and apprehensions that dental practitioners experienced during the height of the COVID-19 outbreak in India in April 2021. The study's findings demonstrate that the study population was generally upbeat and confident that they could quickly overcome their fear.

Where have all the diseases gone during the COVID-19 pandemic?

This article focuses on a marked drop in volumes in the lockdown period during the COVID-19 pandemic across all modalities X-ray, sonography, CT scan and MRI scans and compares the volumes of data between a private and public hospital in Mumbai. This trend has been witnessed globally also. Even with easing of lockdown this has not reflected in an increase in numbers. Imaging volumes of a 1900-bed public hospital and a 220-bed private hospital in Mumbai were collated for all modalities, i.e., X-ray, sonography, CT and MRI for the months January, February 2020- Prelockdown, March 2020 Peri-lockdown, April, May 2020- Lockdown, June Unlock 1.0, July Unlock 2.0. The imaging volumes during lockdown, Unlock, were compared with prelockdown values. It was initially felt that this was due to a fear of visiting hospitals that are considered hotbeds of SARS-CoV-2. However, the same status has persisted over the 2 months of lockdown and the 2 months of unlocking. What is the cause of this huge drop in imaging volumes?

Evaluation of pH, Calcium Ion Release, and Dimensional Stability of an Experimental Silver Nanoparticle-Incorporated Calcium Silicate-Based Cement.

An experimental calcium silicate-based root-end filling material incorporated with silver nanoparticles intended for use in periapical surgeries was developed with the purpose to overcome the drawbacks of existing materials and to satisfy the ideal requirements of root-end filling materials. This study was designed to evaluate the physicochemical properties, pH, calcium ion release, and dimensional stability of the experimental cement, and compare the results with commercially available ProRoot MTA (Dentsply). An independent sample test was used to analyze the data. Mean initial pH (immediately after mixing) of the experimental cement was 10.42 ± 0.04 which was higher than that of MTA. However, there was a significant increase in pH of MTA at 1 day, 2 days, and 7 days. Presence of calcium chloride favored the release of calcium ions which was significantly increased in the experimental group at 24 hours. At the end of 30 days, MTA showed a significant expansion when compared to the experimental cement (p < 0.001). In conclusion, the experimental nanoparticle-incorporated calcium silicate-based cement showed clinically acceptable physicochemical properties.

The "Butterfly Effect" and Its Correlation to the Direction of the Fracture Line in Root Dentin.

INTRODUCTION: The butterfly effect is an optical phenomenon and is related to the presence of sclerotic dentin in the roots. The unique pattern of sclerotic dentin formation produces a characteristic butterfly shape in transverse sections of the roots. The objective of this study was to evaluate the direction of the fracture line in roots that exhibit the butterfly effect. METHODS: Thirty single-rooted premolars with oval-shaped roots were decoronated and embedded in acrylic blocks and subjected to vertical force under a universal testing machine (HPBSD; Tec-Sol India, Chennai, India). Fractured roots were examined under a stereomicroscope (Model no. 080772; Lawrence and Mayo, Mumbai, India) at ×10 magnification to determine the location and direction of the fracture line. To evaluate the correlation between the direction of sclerotic dentin and the direction of the fracture line, teeth were sectioned and observed under a stereomicroscope at ×20 and ×40 magnification. The correlation was analyzed using the Fisher exact test (P < .05 for the coronal and apical thirds and P > .05 for the middle third). RESULTS: Sclerotic dentin was observed more in the apical area and less in the coronal third of the root. The correlation between the direction of sclerotic dentin and the direction of the fracture line was statistically significant in the coronal and apical thirds of the root. CONCLUSIONS: The vertical root fracture that runs buccolingually is correlated to the harder sclerotic dentin present in the mesiodistal direction.