To assess how the current COVID-19 epidemic influenced peoples' utilization of emergency dental services in Beijing, China.
The first-visit patients seeking emergency dental services before or at the ...beginning of the COVID-19 epidemic were retrieved. Their demographic characteristics and the reasons for visiting were recorded and analyzed.
There were 2,537 patients involved in this study. Thirty-eight percent fewer patients visited the dental urgency at the beginning of the COVID-19 epidemic than before. The distribution of dental problems has changed significantly. The proportion of dental and oral infection raised from 51.0% of pre-COVID-19 to 71.9% during COVID-19, and dental trauma decreased from 14.2% to 10.5%. Meanwhile, the non-urgency cases reduced to three-tenths of pre-COVID-19.
Within the limitation of this study, the COVID-19 epidemic had a strong influence on the utilization of emergency dental services.
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•Four of the planetary boundaries have been exceeded and other are under pressure.•Planetary changes pose increasing threats to human health.•Imperative to identify the research ...progress and knowledge gaps in this field.
It has been widely recognised that the threats to human health from global environmental changes (GECs) are increasing in the Anthropocene epoch, and urgent actions are required to tackle these pressing challenges. A scoping review was conducted to provide an overview of the nine planetary boundaries and the threats to population health posed by human activities that are exceeding these boundaries in the Anthropocene. The research progress and key knowledge gaps were identified in this emerging field. Over the past three decades, there has been a great deal of research progress on health risks from climate change, land-use change and urbanisation, biodiversity loss and other GECs. However, several significant challenges remain, including the misperception of the relationship between human and nature; assessment of the compounding risks of GECs; strategies to reduce and prevent the potential health impacts of GECs; and uncertainties in fulfilling the commitments to the Paris Agreement. Confronting these challenges will require rigorous scientific research that is well-coordinated across different disciplines and various sectors. It is imperative for the international community to work together to develop informed policies to avert crises and ensure a safe and sustainable planet for the present and future generations.
The accuracy of digital scanning for complete dental arch and implant-supported complete-arch restorations has been reported. However, research addressing the accuracy of digital scanning methods for ...complete-arch tooth preparation is lacking.
The purpose of this in vitro study was to compare the accuracy of intraoral scanning, impression scanning, and cast scanning for complete-arch preparation.
Maxillary and mandibular jaw typodonts with 28 teeth prepared for complete crowns were used as reference casts and digitized as reference data sets with a desktop scanner. Three digital scanning methods were applied. First, the reference casts were each scanned 10 times with an intraoral scanner to generate the intraoral scanning group data sets. Second, the reference casts were each captured 10 times by using polyvinyl siloxane impression material, and the impressions were scanned with a desktop scanner to generate the impression scanning group data sets. Third, the impressions obtained in the impression scanning group were used to make gypsum casts which were then digitized with a desktop scanner to generate the cast scanning group data sets. Accuracy was determined by trueness and precision. Three-dimensional deviations of the prepared arches and anterior and posterior segments were measured from root mean square values and depicted on color-difference maps. Differences among test groups were analyzed by using a 1-way ANOVA and the post hoc Bonferroni test for normally distributed data or the Kruskal-Wallis test with Bonferroni correction for non-normally distributed data (α=.05).
The trueness of the maxillary arch was significantly higher in the impression scanning group than in the cast scanning and intraoral scanning groups (P<.05), but no significant differences were found among the 3 groups of the mandibular arch (P>.05). The precision of both arches was significantly higher in the impression scanning and intraoral scanning groups than in the cast scanning group (P<.05). Color maps showed horizontal symmetrical displacement in the intraoral scanning group relative to the reference data sets and within-group unilateral distal-end distortion. Irregular arch deformations were noted in the impression scanning group, and buccal and occlusal expansion occurred in the anterior-posterior direction in the cast scanning group. Pooled data for anterior teeth indicated that the trueness was lowest in the intraoral scanning group; however, that for the maxillary anterior teeth did not differ, while that for the mandibular anterior teeth differed significantly among groups (P<.05). For the posterior teeth, deviation was the lowest in the impression scanning group, and significant differences were noted in both arches among the 3 groups (P<.05).
Of the methods tested, impression scanning was the most accurate for the creation of a digital cast of a complete prepared arch.
Introduction
This study aimed to assess live online dental continuing education during COVID‐19 epidemic in China.
Methods
Twenty‐one institutions providing live online dental courses in China during ...COVID‐19 epidemic enrolled in this study. Their online and/or offline course provision before and during the epidemic was retrospectively inquired. If live online education was provided, the number of courses, duration and number of participants per week were further investigated. Time distributions of live online dental courses were recorded and classified as within working time and out of working time. The test period of COVID‐19 epidemic was for two weeks between 16 February and 29 February 2020. The control period of pre‐COVID‐19 epidemic was for ten weeks between 01 November 2019 and 09 January 2020.
Results
The percentages of offline and online courses provided by 21 dental continuing education institutions before COVID‐19 epidemic were 95.2% (20 out of 21) and 28.6% (6 out of 21), respectively. All the institutions suspended offline courses whilst providing two live online courses, on average, per week with 188 minutes duration and 7290 participants during the epidemic. The total number of online courses for 10 weeks before the epidemic was 33, and that for two weeks during the epidemic was 119. The proportion of courses provided within working time raised from 6.1% (2 out of 33) of pre‐COVID‐19 to 46.2% (55 out of 119) during COVID‐19. There were significant differences between before and during the epidemic (P < .001).
Conclusion
The dental continuing education transferred from offline to online dramatically, and live online dental continuing education increased significantly during COVID‐19 epidemic in China.
RNA interference (RNAi) has previously been shown to be effective in western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte) larvae via oral delivery of synthetic double-stranded RNA ...(dsRNA) in an artificial diet bioassay, as well as by ingestion of transgenic corn plant tissues engineered to express dsRNA. Although the RNAi machinery components appear to be conserved in Coleopteran insects, the key steps in this process have not been reported for WCR. Here we characterized the sequence of events that result in mortality after ingestion of a dsRNA designed against WCR larvae. We selected the Snf7 ortholog (DvSnf7) as the target mRNA, which encodes an essential protein involved in intracellular trafficking. Our results showed that dsRNAs greater than or equal to approximately 60 base-pairs (bp) are required for biological activity in artificial diet bioassays. Additionally, 240 bp dsRNAs containing a single 21 bp match to the target sequence were also efficacious, whereas 21 bp short interfering (si) RNAs matching the target sequence were not. This result was further investigated in WCR midgut tissues: uptake of 240 bp dsRNA was evident in WCR midgut cells while a 21 bp siRNA was not, supporting the size-activity relationship established in diet bioassays. DvSnf7 suppression was observed in a time-dependent manner with suppression at the mRNA level preceding suppression at the protein level when a 240 bp dsRNA was fed to WCR larvae. DvSnf7 suppression was shown to spread to tissues beyond the midgut within 24 h after dsRNA ingestion. These events (dsRNA uptake, target mRNA and protein suppression, systemic spreading, growth inhibition and eventual mortality) comprise the overall mechanism of action by which DvSnf7 dsRNA affects WCR via oral delivery and provides insights as to how targeted dsRNAs in general are active against insects.
Although different preparation designs have been proposed for onlays fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM), their effect on marginal adaptation is unclear.
...The purpose of this in vitro study was to investigate the effect of tooth preparation designs on the marginal and internal adaptation of ceramic-reinforced composite resin CAD-CAM onlays.
A traditional preparation with a heavy chamfer on the functional cusp and a contrabevel on the nonfunctional cusp and a shoulder preparation with equal reduction on all cusps were used for mesial-occlusal-distal (MOD) onlay preparations. Ceramic-reinforced composite resin onlays were designed and milled based on the scanned prepared teeth. A digital silicone replica technique was used to determine marginal discrepancies between preparations and onlay restorations. A total of 100 numeric distances (representations of the fit in each region) were measured in 3 distinct regions: the buccal margin, lingual margin, and internal area. Independent Student t tests were used to determine significant differences (α=.05).
Traditional preparation designs resulted in significantly smaller overall discrepancies (50.9 ±0.5 μm and 139.1 ±5.4 μm, P<.001) and smaller marginal discrepancies in the buccal (49.7 ±1.4 μm and 135.8 ±2.2 μm, P<.001) and lingual areas (47.1 ±1.0 μm and 133.4 ±1.1 μm, P<.001).
The marginal adaptation of ceramic-reinforced composite resin CAD-CAM onlays was affected by the preparation design. The traditional preparation design offered better marginal adaptation; therefore, it is recommended in clinical practice.
UMEP (Urban Multi-scale Environmental Predictor), a city-based climate service tool, combines models and tools essential for climate simulations. Applications are presented to illustrate UMEP's ...potential in the identification of heat waves and cold waves; the impact of green infrastructure on runoff; the effects of buildings on human thermal stress; solar energy production; and the impact of human activities on heat emissions. UMEP has broad utility for applications related to outdoor thermal comfort, wind, urban energy consumption and climate change mitigation. It includes tools to enable users to input atmospheric and surface data from multiple sources, to characterise the urban environment, to prepare meteorological data for use in cities, to undertake simulations and consider scenarios, and to compare and visualise different combinations of climate indicators. An open-source tool, UMEP is designed to be easily updated as new data and tools are developed, and to be accessible to researchers, decision-makers and practitioners.
•A GIS-based climate planning tool for researcher and practitioners is presented.•UMEP has broad utility for applications related to e.g. climate change mitigation.•Applications are presented to illustrate UMEP's potential.
This study was to evaluate whether UV light irradiation and He plasma treatment of zirconia disks enhances its biocompatibility with human gingival fibroblasts (HGFs), and to compare the difference ...of two methods. Zirconia disks were prepared and divided into three groups: UVC light treatment (Group UV), He plasma (Group P), and control group. The surface morphology, wettability were analyzed. The cultured HGFs’ adhesive density, morphology, proliferation and collagen synthesis were measured. After UV light and plasma treatment, contact angles decreased. HGFs’ adhesion and proliferation in Group P was the highest (p<0.05) at each time point. HGFs on Group P also released the highest level of Col-1 after 3 and 7 days. Our study demonstrated that plasma and UV light treatment on smooth zirconia improved the hydrophilic property of surface in different mechanism and He plasma had the better effect on cells adhesion, proliferation, and especially on collagen synthesis.
The aim of this study was to evaluate the crosslinking effect of the radio-frequency atmospheric-pressure glow discharge (RF-APGD) plasma jet treatment on dentin collagen. The dentin collagen was ...treated by an RF-APGD plasma jet with the gas temperature of 4°C under different treatment times, while the control was a non-treatment group. The dentin collagen was characterized in terms of atomic force microscopy-based nanoindentation, differential scanning calorimeter, Raman analysis and X-ray photoelectron spectroscopy (XPS) measurement. The crosslinking effect of the plasma-treated dentin collagen was found compared to that of the control group. The elastic modulus and denaturation temperature of the dentin collagen after plasma treatment for 30 s were significantly higher than those in the control group (p<0.05). The RF-APGD plasma jet treatment can promote the crosslinking of the dentin collagen, which is of great significance to improve its mechanical and thermal stabilities.
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