The influence of thermomechanical compaction on the marginal adaptation of 4 different hydraulic sealers: a comparative ex vivo study

Since there are no data in the literature regarding the comparison of the marginal adaptation of hydraulic sealers when used with a single-cone technique or through thermomechanical compaction, this study aimed to evaluate the behavior of four different endodontic sealers used with the two above-mentioned obturation techniques by evaluating the marginal gap existing between the obturation materials and the dentinal walls through scanning electron microscopy. Given this objective, a total of 104 single-rooted, straight canal teeth were selected and divided into four subgroups according to the selected endodontic sealer ((AH) Plus Bioceramic Sealer (AHP), EndoSequence BC Sealer HiFlow (ES), C-Root SP (CR), and GuttaFlow Bioseal (GF)). Each tooth was decoronated and instrumented with the HyFlex EDM/CM systematics up to 30.04. After irrigation procedures, the teeth of each subgroup were divided into two groups and obturated according to two different obturation techniques: the single-cone technique (SC) and the thermomechanical compaction technique (TC). After the required sealer setting time, each tooth was sectioned in three parts at 3, 6, and 9 mm from the apex, and each section was observed with a scanning electron microscope. The marginal gap of each sample was measured using G* Power Software v3.1, and the statistical analysis was performed using the Kruskal–Wallis test, followed by a post hoc Dunn’s test. Results showed that there were not any statistically significant differences in terms of the marginal gap between the two different above-mentioned obturation techniques for each sealer, except for the middle third of root canals, where a statistically significant difference was found for AHP, ES, and GF sealers. In conclusion, the thermomechanical compaction of hydraulic sealers and gutta-percha guarantees better sealing than the single-cone technique when the root canal shape is not rounded

The COVID-19 pandemic and its global effects on dental practice : An International survey

Objectives: A multicentre survey was designed to evaluate the impact of COVID-19 outbreak on dental practice worldwide, estimate the COVID-19 related symptoms/signs, work attitudes and behaviour and the routine use of protective measures and Personal Protective Equipment (PPE). Methods: A global survey using a standardized questionnaire with research groups from 36 countries was designed. The questionnaire was developed and pretested during April 2020 and contained three domains: 1) Personal data; 2) COVID-19 positive rate and symptoms/signs presumably related to the coronavirus; 3) Working conditions and PPE adopted after the outbreak. Countries' data were grouped by the Country Positive Rate (CPR) during the survey period and by Gross-National-Income per capita. An ordinal multinomial logistic regression model was carried out with COVID-19 self-reported rate referred by dental professionals as dependent variable to assess the association with questionnaire items. Results: A total of 52,491 questionnaires were returned with a male/female ratio of 0.63. Out of the total respondents, 7,859 dental professionals (15%) reported symptoms/signs compatible with COVID-19. More than half of the sample (n = 27,818; 53%) stated to use FFP2/N95 masks, while 21,558 (41.07%) used eye protection. In the bivariate analysis, CPR and N95/FFP2 were significantly associated (OR = 1.80 95% =5.20 95% 95% CI = 1.60/2.82 and OR CI = 1.44/18.80, respectively), while Gross-National-Income was not statistically associated with CPR (OR = 1.09 CI = 0.97/1.60). The same significant associations were observed in the multivariate analysis. Conclusions: Oral health service provision has not been significantly affected by COVID-19, although access to routine dental care was reduced due to country-specific temporary lockdown periods. While the dental profession has been identified at high-risk, the reported rates of COVID-19 for dental professionals were not significantly different to those reported for the general population in each country. These findings may help to better plan oral health care for future pandemic events

Human Ischaemic Cascade Studies Using SH-SY5Y Cells: a Systematic Review and Meta-Analysis

Low translational yield for stroke may reflect the focus of discovery science on rodents rather than humans. Just how little is known about human neuronal ischaemic responses is confirmed by systematic review and meta-analysis revealing that data for the most commonly used SH-SY5Y human cells comprises only 84 papers. Oxygen-glucose deprivation, H2O2, hypoxia, glucose-deprivation and glutamate excitotoxicity yielded − 58, − 61, − 29, − 45 and − 49% injury, respectively, with a dose-response relationship found only for H2O2 injury (R2 = 29.29%, p I2 = 99.36%, df = 132, p R2 = 44.77%, p R2 = 28.64%, p R2 = 4.13%, p p 2O2 injury reported only improvement. In studies using glucose deprivation, intervention generally worsened outcome. There was insufficient data to rank individual interventions, but of the studies reporting greatest improvement (> 90% effect size), 7/13 were of herbal medicine constituents (24.85% of the intervention dataset). We conclude that surprisingly little is known of the human neuronal response to ischaemic injury, and that the large impact of methodology on outcome indicates that further model validation is required. Lack of evidence for randomisation, blinding or power analysis suggests that the intervention data is at substantial risk of bias

The COVID-19 pandemic and its global effects on dental practice. An international survey

Objectives A multicentre survey was designed to evaluate the impact of COVID-19 outbreak on dental practice worldwide, estimate the COVID-19 related symptoms/signs, work attitudes and behaviour and the routine use of protective measures and personal protective equipment (PPE). Methods A global survey using a standardized questionnaire with research groups from 36 countries was designed. The questionnaire was developed and pretested during April 2020 and contained three domains: 1) personal data; 2) COVID-19 positive rate and symptoms/signs presumably related to the coronavirus; 3) working conditions and PPE adopted after the outbreak. Countries’ data were grouped by the country positive rate (CPR) during the survey period and by Gross-National-Income per capita. An ordinal multinomial logistic regression model was carried out with COVID-19 self-reported rate referred by dental professionals as dependent variable to assess the association with questionnaire items. Results A total of 52,491 questionnaires were returned with a male/female ratio of 0.63. Out of the total respondents, 7,859 dental professionals (15%) reported symptoms/signs compatible with COVID-19. More than half of the sample (n=27,818; 53%) stated to use FFP2/N95 masks, while 21,558 (41.07%) used eye protection. In the bivariate analysis, CPR and N95/FFP2 were significantly associated (OR=1.80 95%CI=1.60/2.82 and OR=5.20 95%CI=1.44/18.80, respectively), while Gross-National-Income was not statistically associated with CPR (OR=1.09 95%CI=0.97/1.60). The same significant associations were observed in the multivariate analysis. Conclusions Oral health service provision has not been significantly affected by COVID-19, although access to routine dental care was reduced due to country-specific temporary lockdown periods. While the dental profession has been identified at high-risk, the reported rates of COVID-19 for dental professionals were not significantly different to those reported for the general population in each country. These findings may help to better plan oral health care for future pandemic events

Microscope-aided endodontic treatment of maxillary first premolars with three roots: A case series

Maxillary premolars have a highly variable root canal morphology. However, the presence of three roots is a rare occurrence. This clinical article describes the unusual anatomy detected in maxillary premolars during routine endodontic treatment using microscope. The diagnosis and clinical management of maxillary first premolars with three roots and canals using radiographic interpretation, access cavity modification and visual enhancement with operative microscopes is discussed in the article

Phyto-fabrication of AgNPs using leaf extract of Vitex trifolia: potential to antibacterial, antioxidant, dye degradation, and their evaluation of non-toxicity to Chlorella vulgaris

The study assessed the bactericidal effects of green rapid biogenic synthesis of Vitex trifolia leaves AgNPs on MDR bacteria. The synthesis of AgNPs is indicated by a color change from yellow to dark brown. The ultra-visible spectrophotometer displays AgNPs at 430 nm max. This demonstrates that ions (Ag+) were converted to silver (Ag), indicating the formation of silver nanoparticles. The synthesized nanoparticles were confirmed by their crystalline nature, shape, size, and functional groups via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X- ray spectroscopy (EDAX), and transmission electron microscopy (TEM). Biomolecules contain aqueous Vitex extract for capping and reducing the AgNPs. The nanoparticles have a face-centered cubic structure (FCC) crystallized. The antibacterial activity against Staphylococcus aureus, Vibrio cholerae, and Klebsiella pneumoniae exhibited a maximum zone of growth inhibition at 75 µg/mL. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AgNPs against the clinically isolated pathogen S. aureus were 3.12 µg/mL and 4.5 µg/mL. Furthermore, time-dependent killing kinetic experiments showed that a 6 h AgNPs treatment was sufficient to fully inhibit all bacterial growth. AgNPs at a concentration of 250 µg/mL demonstrated antioxidant activity as measured by the FRAP and DPPH tests (85% and 90%, respectively). AgNPs demonstrated efficient photocatalytic activity in the degradation of methylene blue (MB) and achieved their highest photocatalytic activity (95%) after 2.30 h. Besides, the synthesis of AgNPs was targeted towards C. vulgaris algae, and exhibited deleterious effects even at larger concentrations. The chosen AgNPs concentration reduced chlorophyll, impeded algal development, and damaged the whole membrane system, as evidenced by the increased electrolyte leakage and malondialdehyde (MDA) and glutathione s-transferase (GSH) content after AgNPs exposure. Our report demonstrates that AgNPs V. trifolia have promising antibacterial, antioxidant, and potential dye degradation activities and can be employed in biomedical applications.</p