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The novel Coronavirus pandemic defines a new risk for all dental practitioners, hygienists, and dental assistants. As an increasing number of dentists are now developing this disease, we wanted to provide some measures to manage this risk in the dental practice, by undergoing a review of the current literature. This minireview searches the literature for articles that both defined the infection risk in the dental practice and provided evidence on the efficacy of some procedures on reducing the infection risk. Several articles have already pointed out some necessary measures: fewer patients have to be admitted to the practice, a short triage should be carried out, and the appropriate measures of protection have to be used. On the basis of the literature collected, a short questionnaire and a flowchart is proposed to define the risk that each patient carries, and to appropriately adapt each procedure based on the patient’s risk. The literature is still limited on this subject, but on the basis of what is available, dental practices have to adapt to the situation in order to protect dental health professionals. Impact statement Dentists have always been taught how to protect themselves and their patients from potential blood-borne pathogens, but the Coronavirus pandemic has brought a new unprecedented challenge to the world of dentistry; we therefore reviewed the literature to provide suggestions on how to accordingly change dental practice prevention.

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Zirconium oxide, known as zirconia, is a ceramic material with optimal esthetical and mechanical properties. Zirconia stabilized with yttrium oxide has the best properties for medical uses. A stress on ZrO z surface creates a crystalline modification that opposes to propagation of cracks. Zirconia core for fixed partial dentures (FPD) on anterior and posterior teeth and on implants are now available. Clinical evaluations after 3 years report good percentage of success for zirconia fixed partial denture. Zirconia biocompatibility was studied in vivo and in vitro by orthopedic research; no adverse responses were reported on insertion of ZrO z samples in bone or muscle. In vitro experimentation showed absence of mutation and a good viability of cells cultured on this material. Zirconium dioxide is white, has good wear resistance surface grinding could reduce toughness (6); also Kosmac and mechanical properties similar to a metal; it is also confirmed this assertion reporting a lower mean strength known as Zirconia. zr0 2 crystals and can be organized of zirconium oxide after surface grinding (7). Moreover, in different patterns: Monocline (M), Cubic (C) and ageing is another important feature of Zr0 2 ; Swan Tetragonal (T). In order to stabilize zirconium oxide it is reported that zirconia can lose its mechanical features if necessary to add other metallic oxides, such as MgO, CaO placed in a wet enviroment for a long time (8). and YP3; Yttrium stabilized zirconia nowadays is the

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The purpose of this clinical research was to evaluate peri-implant marginal changes around immediate implants placed either with the application of SCTG or XCM or without soft tissue grafting. A total of 48 patients requiring a single implant-supported restoration in the anterior jaw were selected for inclusion. Three surgical procedures were performed, as follows: type 1 implant with subepithelial connective tissue graft (SCTG), type 1 implant with xenogenic collagen matrix (XCM), and type 1 implant without soft tissue augmentation (NG) (control group). The marginal change of peri-implant soft tissue, facial soft tissue thickness (FSTT), peri-implant health status, esthetics, and patient satisfaction were assessed at one year after surgery. All of the placed implants showed a survival rate of 100%. No significant differences in FSTT were recorded between the SCTG group and the XCM group after treatment ( P > 0.05 ), while the NG group presented a significant difference ( P < 0.05 ). Patients in the NG group lost significantly more in the buccal marginal level than did patients in the SCTG group and those in the XCM group ( P < 0.05 ). The favourable success rate recorded in all groups confirmed immediate tooth replacement as a choice of treatment for a missing anterior single tooth. The NG group presented significant changes of FSTT and buccal marginal level, while XCM constituted a viable alternative to SCTG.

Zirconia, a biomaterial widely used in dentistry, has recently attracted much attention for its mechanical strength and toughness. Previously, its lack of mutagenic and carcinogenic power was reported. We describe here other essential aspects to be taken into account to define in vitro the biocompatibility of a material: the growth rate, viability, and adhesion capacity of normal stabilized cells growing on it. To this aim, immortalized RAT-1 fibroblasts, growing either on zirconia and on feldspatic (FE) ceramics were compared. In particular, the level of expression and the intra-and extra-cellular organization of fibronectin, a glycoprotein involved in cellular adhesion and migration during tissue repair, was analyzed. Fibroblasts cultured on zirconia showed a higher growth rate, and underwent necrosis at lower levels than cells on FE ceramic, whereas either materials did not stimulate apoptosis. Adhesion capacity of fibroblasts was evaluated measuring adherent cell nucleic acids with the fluorimetric CyQuant 1 assay, and it was found significantly higher in cells cultured on zirconia than on FE ceramic. This finding may be explained by the higher and more precocious expression of the adhesion protein fibronectin observed by indirect immunofluorescence in fibroblasts on zirconia. Overall, the results suggest that zirconia, exerting low cytotoxicity and strongly inducing adhesion capacity, increases cellular growth rate of fibroblasts. All these features suggest that zirconia could represent a more suitable biomaterial than FE ceramic for prosthesis in dentistry.2007 Wiley Periodicals, Inc. J Biomed Mater Res 86A: [959][960][961][962][963][964][965][966][967][968] 2008

Tantalum is obtained from the minerals colombite, tantalite and euxenite. It is greyish silver, heavy and very hard. Tantalum does not react with body fluids and is used to make surgical equipment. Tantalum also does not irritate the body and is used to make surgical sutures as well as implants, such as artificial joints and cranial plates. Bone growth around tantalum covered by calcium phosphate is described by in vitro experimentations. in vivo. Bioactive properties of porous tantalum have been recently developed. Porous tantalum consists of an interconnected porous structure with an average porosity diameter of approximately 400 microm. Hollow spheres with nanometre-to-micrometer dimensions are widely used in different range of applications such as drug delivery carriers and bioreactors. Porous tantalum metal is currently used in orthopaedic for manufacturing of structural component for primary and revision total hip and knee replacements and, more recently, in spine surgery. Good clinical outcomes have been achieved especially in hip revision surgery, using tantalum implants, and promising short term follow up have been reported for knee revision surgery. Some patents for tantalum biomedical applications have been obtained and this article reviews various recent patents on this material. Many patents are developed on tantalum for biomedical application. This paper review some of them with particular interested for biomedical applications in orthopaedic and dentistry.