Review of nanomaterials in dentistry: interactions with the oral microenvironment, clinical applications, hazards, and benefits.

Interest in the use of engineered nanomaterials (ENMs) as either nanomedicines or dental materials/devices in clinical dentistry is growing. This review aims to detail the ultrafine structure, chemical composition, and reactivity of dental tissues in the context of interactions with ENMs, including the saliva, pellicle layer, and oral biofilm; then describes the applications of ENMs in dentistry in context with beneficial clinical outcomes versus potential risks. The flow rate and quality of saliva are likely to influence the behavior of ENMs in the oral cavity, but how the protein corona formed on the ENMs will alter bioavailability, or interact with the structure and proteins of the pellicle layer, as well as microbes in the biofilm, remains unclear. The tooth enamel is a dense crystalline structure that is likely to act as a barrier to ENM penetration, but underlying dentinal tubules are not. Consequently, ENMs may be used to strengthen dentine or regenerate pulp tissue. ENMs have dental applications as antibacterials for infection control, as nanofillers to improve the mechanical and bioactive properties of restoration materials, and as novel coatings on dental implants. Dentifrices and some related personal care products are already available for oral health applications. Overall, the clinical benefits generally outweigh the hazards of using ENMs in the oral cavity, and the latter should not prevent the responsible innovation of nanotechnology in dentistry. However, the clinical safety regulations for dental materials have not been specifically updated for ENMs, and some guidance on occupational health for practitioners is also needed. Knowledge gaps for future research include the formation of protein corona in the oral cavity, ENM diffusion through clinically relevant biofilms, and mechanistic investigations on how ENMs strengthen the tooth structure

Practical considerations for conducting ecotoxicity test methods with manufactured nanomaterials: what have we learnt so far?

This review paper reports the consensus of a technical workshop hosted by the European network, NanoImpactNet (NIN). The workshop aimed to review the collective experience of working at the bench with manufactured nanomaterials (MNMs), and to recommend modifications to existing experimental methods and OECD protocols. Current procedures for cleaning glassware are appropriate for most MNMs, although interference with electrodes may occur. Maintaining exposure is more difficult with MNMs compared to conventional chemicals. A metal salt control is recommended for experiments with metallic MNMs that may release free metal ions. Dispersing agents should be avoided, but if they must be used, then natural or synthetic dispersing agents are possible, and dispersion controls essential. Time constraints and technology gaps indicate that full characterisation of test media during ecotoxicity tests is currently not practical. Details of electron microscopy, dark-field microscopy, a range of spectroscopic methods (EDX, XRD, XANES, EXAFS), light scattering techniques (DLS, SLS) and chromatography are discussed. The development of user-friendly software to predict particle behaviour in test media according to DLVO theory is in progress, and simple optical methods are available to estimate the settling behaviour of suspensions during experiments. However, for soil matrices such simple approaches may not be applicable. Alternatively, a Critical Body Residue approach may be taken in which body concentrations in organisms are related to effects, and toxicity thresholds derived. For microbial assays, the cell wall is a formidable barrier to MNMs and end points that rely on the test substance penetrating the cell may be insensitive. Instead assays based on the cell envelope should be developed for MNMs. In algal growth tests, the abiotic factors that promote particle aggregation in the media (e.g. ionic strength) are also important in providing nutrients, and manipulation of the media to control the dispersion may also inhibit growth. Controls to quantify shading effects, and precise details of lighting regimes, shaking or mixing should be reported in algal tests. Photosynthesis may be more sensitive than traditional growth end points for algae and plants. Tests with invertebrates should consider non-chemical toxicity from particle adherence to the organisms. The use of semi-static exposure methods with fish can reduce the logistical issues of waste water disposal and facilitate aspects of animal husbandry relevant to MMNs. There are concerns that the existing bioaccumulation tests are conceptually flawed for MNMs and that new test(s) are required. In vitro testing strategies, as exemplified by genotoxicity assays, can be modified for MNMs, but the risk of false negatives in some assays is highlighted. In conclusion, most protocols will require some modifications and recommendations are made to aid the researcher at the bench. [Authors]]]> Nanostructures; Toxicity Tests; Ecotoxicology/methods; Guidelines; eng https://serval.unil.ch/resource/serval:BIB_5FCE25CBF6A9.P001/REF.pdf http://nbn-resolving.org/urn/resolver.pl?urn=urn:nbn:ch:serval-BIB_5FCE25CBF6A95 info:eu-repo/semantics/altIdentifier/urn/urn:nbn:ch:serval-BIB_5FCE25CBF6A95 info:eu-repo/semantics/submittedVersion info:eu-repo/semantics/openAccess Copying allowed only for non-profit organizations https://serval.unil.ch/disclaimer application/pdf oai:serval.unil.ch:BIB_5FCE8EA1AD9C 2022-02-19T02:22:28Z <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_5FCE8EA1AD9C Apprendre à suivre une règle : jeux d'alternance et constitution du sujet moral Erard, Y. info:eu-repo/semantics/bookPart incollection 2007 Morale et évolution biologique oai:serval.unil.ch:BIB_5FC219D991AA 2022-02-19T02:22:28Z <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_5FC219D991AA Réflexion sur la réduction de peine en cas de détention illicite Parein, Loïc info:eu-repo/semantics/article article 2015 Revue de l'avocat, vol. 4, no. 15, pp. 166-170 info:eu-repo/semantics/altIdentifier/pissn/1422-5778 fre https://serval.unil.ch/resource/serval:BIB_5FC219D991AA.P001/REF.pdf info:eu-repo/semantics/publishedVersion info:eu-repo/semantics/restrictedAccess Restricted: indefinite embargo Copying allowed only for non-profit organizations https://serval.unil.ch/disclaimer application/pdf oai:serval.unil.ch:BIB_5FC2874DDD0E 2022-02-19T02:22:28Z <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_5FC2874DDD0E Radial Ultrasound-Assisted Transbronchial Biopsy: A New Diagnostic Approach for Non-Resolving Pulmonary Infiltrates in Neutropenic Hemato-Oncological Patients. info:doi:10.1007/s00408-016-9947-3 info:eu-repo/semantics/altIdentifier/doi/10.1007/s00408-016-9947-3 info:eu-repo/semantics/altIdentifier/pmid/27704258 Bernasconi, M. Casutt, A. Koutsokera, A. Letovanec, I. Tissot, F. Nicod, L.P. Lovis, A. info:eu-repo/semantics/article article 2016-12 Lung, vol. 194, no. 6, pp. 917-921 info:eu-repo/semantics/altIdentifier/eissn/1432-1750 urn:issn:0341-2040 <![CDATA[The role of radial-endobronchial ultrasound (R-EBUS) assisted transbronchial biopsy (TBB) for the diagnosis of peripheral pulmonary lesions is well established. However, no study has addressed its safety and value in hemato-oncological patients presenting with non-resolving infiltrates during persistent febrile neutropenia. To assess safety and feasibility of R-EBUS assisted TBB in severe thrombocytopenic and neutropenic patients. Over a period of 18 months, eight patients were assessed with R-EBUS assisted TBB after adequate platelet transfusion. This technique allowed precise localisation and sampling of the pulmonary lesions in seven of eight patients. In the seven patients, R-EBUS assisted TBB enabled treatment optimization. Invasive fungal infection was diagnosed in four patients, idiopathic acute fibrinous and organising pneumonia in three patients, and a granulomatous inflammation of undetermined origin in one patient. Importantly, no complications, such as bleeding, were observed. R-EBUS assisted TBB is a promising and safe procedure for the evaluation of nonresolving pulmonary infiltrates in febrile neutropenic hemato-oncological patients