[COVID-19 in the Intensive Care Unit: Medical, Nursing, and Physical Therapy Challenges]. / COVID-19 in der Intensivstation: medizinische, pflegerische und physiotherapeutische Herausforderungen.

COVID-19 in the Intensive Care Unit: Medical, Nursing, and Physical Therapy Challenges Abstract. The treatment of patients with COVID-19 is a big challenge for intensive care units: substantial additional staff and material is needed to treat the surge of patients admitted in short time. Treatment is difficult as many patients present with multiple organ failure, including acute respiratory distress syndrome (ARDS). Mostly, oxygenation is substantially impaired and compliance low, and many patients need prone positioning. This article deals with the difficulties during the first surge of patients with COVID-19. The suffering of the relatives who were not allowed to visit must also be considered.

Undergraduate dental students' perspective on the implementation of digital dentistry in the preclinical curriculum: a questionnaire survey.

BACKGROUND: Digitalisation is an expanding field in dentistry and implementation of digital teaching methods in dental education is an essential part of modern education. Therefore, two digital training modules were implemented in the preclinical curriculum at the Justus Liebig University Giessen. The aim of this study was to assess the students' perspective on the implementation with a questionnaire survey. METHODS: Since the fall term 2017/18, students of the course of dental prosthodontics I attended the training module I, where they learned to use computer-aided learning (CAL) approaches for the digital analysis of tooth preparations. In training module II, students of the course of dental prosthodontics II learned how to manufacture a computer-aided design/computer-aided manufacturing restoration. After the completion of the training modules, all students starting with the fall term 2017/18 to the spring term 2019 were asked to fill in a questionnaire regarding the aspects of handling, didactic benefit, motivation, and overall assessment. RESULTS: Students rated the implementation of digital aspects in teaching as positive in terms of handling, didactic benefit, and motivation, but gave preference to the assessment of the tooth preparations by dental instructors. In addition, students assessed the feedback from the faculty regarding tips and tricks better than the digital feedback. More than 90% of the students indicated that they could imagine using an intraoral scanner for treatment of patients in the dental office in future. CONCLUSIONS: The results of the present study revealed a positive perspective of students on the implementation of digital dentistry in the preclinical curriculum. However, difficulties with CAL systems were reported and most students preferred evaluation of preparation by dental instructors. Thus, CAL approaches offer an additional teaching method besides the traditional teaching of manual skills.

A questionnaire on the use of digital denture impressions in a preclinical setting.

Since February 2010, intraoral scanning (Lava COS system, 3M ESPE, Seefeld, Germany) has been integrated into the preclinical curriculum at the Department of Prosthodontics of the Justus Liebig University. All students were given a lecture and were trained using a guided scan exercise. After preparing three teeth (mandibular first premolars and mandibular first molar in the 4th quadrant) for cast crowns, the students were asked to scan the maxillary and mandibular teeth. Their acceptance of the new module, "Scanning," was analyzed with the use of a questionnaire (n = 108). The evaluation showed that 63.9% of the students perceived the digital impression to be informative, and had an overall positive opinion of this new digital technology. Concerning the difficulty of the scanning process, approximately 60.2% considered it to be manageable, while 55.6% reported that the magnified view of their preparations improved their understanding of preparing chamfer finish lines. Altogether, the majority of students appreciated this intraoral scanning device as an enhancement of their education. They indicated that this method contributes to a better understanding of crown preparations. In conclusion, the implementation of intraoral scanning seems promising in preclinical education and will be continued in the curriculum.

Case studies putting the decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping) into practice.

Case studies covering carbonaceous nanomaterials, metal oxide and metal sulphate nanomaterials, amorphous silica and organic pigments were performed to assess the Decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping). The usefulness of the DF4nanoGrouping for nanomaterial hazard assessment was confirmed. In two tiers that rely exclusively on non-animal test methods followed by a third tier, if necessary, in which data from rat short-term inhalation studies are evaluated, nanomaterials are assigned to one of four main groups (MGs). The DF4nanoGrouping proved efficient in sorting out nanomaterials that could undergo hazard assessment without further testing. These are soluble nanomaterials (MG1) whose further hazard assessment should rely on read-across to the dissolved materials, high aspect-ratio nanomaterials (MG2) which could be assessed according to their potential fibre toxicity and passive nanomaterials (MG3) that only elicit effects under pulmonary overload conditions. Thereby, the DF4nanoGrouping allows identifying active nanomaterials (MG4) that merit in-depth investigations, and it provides a solid rationale for their sub-grouping to specify the further information needs. Finally, the evaluated case study materials may be used as source nanomaterials in future read-across applications. Overall, the DF4nanoGrouping is a hazard assessment strategy that strictly uses animals as a last resort.

A decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping).

The European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) 'Nano Task Force' proposes a Decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping) that consists of 3 tiers to assign nanomaterials to 4 main groups, to perform sub-grouping within the main groups and to determine and refine specific information needs. The DF4nanoGrouping covers all relevant aspects of a nanomaterial's life cycle and biological pathways, i.e. intrinsic material and system-dependent properties, biopersistence, uptake and biodistribution, cellular and apical toxic effects. Use (including manufacture), release and route of exposure are applied as 'qualifiers' within the DF4nanoGrouping to determine if, e.g. nanomaterials cannot be released from a product matrix, which may justify the waiving of testing. The four main groups encompass (1) soluble nanomaterials, (2) biopersistent high aspect ratio nanomaterials, (3) passive nanomaterials, and (4) active nanomaterials. The DF4nanoGrouping aims to group nanomaterials by their specific mode-of-action that results in an apical toxic effect. This is eventually directed by a nanomaterial's intrinsic properties. However, since the exact correlation of intrinsic material properties and apical toxic effect is not yet established, the DF4nanoGrouping uses the 'functionality' of nanomaterials for grouping rather than relying on intrinsic material properties alone. Such functionalities include system-dependent material properties (such as dissolution rate in biologically relevant media), bio-physical interactions, in vitro effects and release and exposure. The DF4nanoGrouping is a hazard and risk assessment tool that applies modern toxicology and contributes to the sustainable development of nanotechnological products. It ensures that no studies are performed that do not provide crucial data and therefore saves animals and resources.

A critical appraisal of existing concepts for the grouping of nanomaterials.

The grouping of substances serves to streamline testing for regulatory purposes. General grouping approaches for chemicals have been implemented in, e.g., the EU chemicals regulation. While specific regulatory frameworks for the grouping of nanomaterials are unavailable, this topic is addressed in different publications, and preliminary guidance is provided in the context of substance-related legislation or the occupational setting. The European Centre for Ecotoxicology and Toxicology of Chemicals Task Force on the Grouping of Nanomaterials reviewed available concepts for the grouping of nanomaterials for human health risk assessment. In their broad conceptual design, the evaluated approaches are consistent or complement each other. All go beyond the determination of mere structure-activity relationships and are founded on different aspects of the nanomaterial life cycle. These include the NM's material properties and biophysical interactions, specific types of use and exposure, uptake and kinetics, and possible early and apical biological effects. None of the evaluated grouping concepts fully take into account all of these aspects. Subsequent work of the Task Force will aim at combining the available concepts into a comprehensive 'multiple perspective' framework for the grouping of nanomaterials that will address all of the mentioned aspects of their life cycles.

Risk assessment of amorphous silicon dioxide nanoparticles in a glass cleaner formulation.

Since nanomaterials are a heterogeneous group of substances used in various applications, risk assessment needs to be done on a case-by-case basis. Here the authors assess the risk (hazard and exposure) of a glass cleaner with synthetic amorphous silicon dioxide (SAS) nanoparticles during production and consumer use (spray application). As the colloidal material used is similar to previously investigated SAS, the hazard profile was considered to be comparable. Overall, SAS has a low toxicity. Worker exposure was analysed to be well controlled. The particle size distribution indicated that the aerosol droplets were in a size range not expected to reach the alveoli. Predictive modelling was used to approximate external exposure concentrations. Consumer and environmental exposure were estimated conservatively and were not of concern. It was concluded based on the available weight-of-evidence that the production and application of the glass cleaner is safe for humans and the environment under intended use conditions.

Effect of surface condition and storage time on the repairability of temporary crown and fixed partial denture materials.

OBJECTIVES: The aim of the present study was to investigate which parameters (chemical nature, time after mixing, surface characteristics) might affect the repair strength of temporary crown and bridge materials (t-c&b). METHODS: Four different t-c&bs (Cool Temp Natural, Protemp 3 Garant, Structur Premium, Trim) were investigated using a shear-bond strength (SBS) setup. A cylinder (2 mm x 2.37 mm) of identical t-c&b (n=10) was bonded onto a specimen surface of either freshly set t-c&b (10 min after mixing) or onto specimens that were stored for 24h (37 degrees C, distilled water) and 7 days (thermocycling x 5,000, 5-55 degrees C=TC), respectively. The specimen surface was roughened with SiC paper (grit size 320) or left as it was (specimens stored for 10 min) prior to repair to retain the oxygen-inhibition layer. In addition, mono-block specimens were fabricated as control. The thickness of the oxygen-inhibition layer and the surface morphology was determined. Statistical analysis was carried out with an ANOVA followed by parametric tests (p=0.05). RESULTS: SBS values ranged from 10 to 40 MPa. Trim showed lowest SBS values for most storage conditions. Material, surface characteristics and time after mixing significantly affected the SBS (ANOVA p<0.001). TC significantly reduced the SBS (p<0.05) for all t-c&bs except for Trim (p>0.05). CONCLUSIONS: In case of monomethacrylates, storage and surface condition do not affect the repair strength. In contrast, the repair quality of dimethacrylates greatly depends on the material. In any case, roughening the surface is recommended, even if an oxygen-inhibition layer is present.

Influence of denture improvement on the nutritional status and quality of life of geriatric patients.

UNLABELLED: Recent research suggests that there is a correlation between nutrition, oral health, dietary habits, patients' satisfaction and their socio-economic status. However, the dependent and independent variables have remained unclear. OBJECTIVE: This exploratory interventional study aimed to identify the impact of denture improvement on the nutritional status as well as the oral health-related quality of life in geriatric patients. MATERIALS AND METHODS: Forty-seven patients who were capable of feeding themselves (minimum age: 60 years) and with dentures requiring repair or replacement were selected from a random sample of 100 residents of two nursing homes. Before and 6 months after the dentures were optimised a Mini Nutritional Assessment (MNA) and a masticatory function test were carried out. Nutritional markers (pre-albumin, serum albumin, zinc) were determined and an OHIP-G14 (Oral Health Impact Profile, German version) was recorded in order to determine the effect of the optimised oral situation on the patient's nutritional status and oral health-related quality of life. RESULTS: Despite the highly significant improvement in masticatory ability after the optimisation of the dentures, no general improvement regarding the nutritional status was observed since the albumin, zinc and MNA values remained unchanged and pre-albumin even decreased. CONCLUSION: Since masticatory ability and masticatory efficiency are not the only factors affecting this, prosthetic measures alone apparently cannot effect a lasting improvement in nutritional status as masticatory ability and masticatory efficiency are not the only factors of influence. Nutrition is not only a matter of masticatory function, but also depends on other influencing factors (e.g. habits, taste and cultural customs as well as financial and organisational aspects).

Dental health and orthodontic treatment need among dental students treated by certified orthodontists and general dental practitioners.

OBJECTIVES: To assess the general dental health, orthodontic status, and orthodontic treatment need in young adults. METHOD AND MATERIALS: The subjects were 121 first-year dental students. Fifty-one individuals without orthodontic treatment were compared with 70 orthodontically treated individuals. It was differentiated whether orthodontic treatment had been performed by a certified orthodontic specialist or a general dental practitioner. DMF(T) and DM(T) Index values were recorded. Dental casts were analyzed, and the orthodontic treatment need was assessed using the Dental Health Component (DHC) of the Index of Orthodontic Treatment Need (IOTN). RESULTS: Orthodontically treated subjects exhibited statistically significantly lower DMF(T) and DM(T) values than untreated individuals. Treatment performed by a certified orthodontist resulted in statistically significantly better treatment results with more Class I relationships and less crowding. The remaining degree of orthodontic treatment need was also lower in subjects treated by a certified orthodontist. A moderate to very high degree of treatment need (DHC degrees III to V) was present in 59% of the subjects treated by a general practitioner but only 29% of the subjects treated by a certified orthodontist. CONCLUSION: Orthodontic treatment improves general dental health. Treatment performed by a certified orthodontist leads to better treatment results and lower remaining treatment need compared with that performed by a general practitioner.

Light-emitting diodes for the illumination of algae in ecotoxicity testing.

Ecotoxic effects of chemicals, preparations, and environmental samples are routinely quantified in standardized algae growth inhibition tests using microalgae like Desmodesmus subspicatus. The intention of this investigation was to prove the suitability of light-emitting diodes (LEDs) as an alternative to tubular discharge lamps in algae growth inhibition tests. This was approached by demonstrating that growth of algae was similar with both illuminating devices. Growth factors of growth controls were determined using LEDs. Growth curves of different light intensities of LEDs were compared with those of tubular discharge lamps. By testing certain chemicals with both illumination methods comparable results for E(r)C50 values were obtained. It could be shown that small-scale construction of incubators using LEDs is possible and could be advantageous, especially for the illumination of algae in 96-well microplate growth inhibition assays.