941 resultados para Color in dentistry


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The use of medicines during pregnancy deserves special attention from dentists due to the potential risks to fetal development. The prescription of antimicrobial drugs during this period must be based not only on the etiology of the disease but also on the drug's effect on the embryo, which may be toxic, possibly leading to irreversible lesions. Interest in studies of the teratogenic effects of drugs increased in response to reports of the high incidence of phocomelia in patients treated with thalidomide. Although teratogenicity has long been known, pregnant women today are still exposed to this risk. The effects of drugs depend on the level of susceptibility of the fetus and on the period of exposure during pregnancy. In this context, and considering the paucity of studies on this subject in dentistry, the aim of this review was to offer an up-to-date compilation of data on the antimicrobial drugs most frequently used during pregnancy and the effects of their use.

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The aim of this paper is to compare the fluoride-releasing and mechanical properties of an experimental luting glass ionomer cement, which has a modified composition and a commercial luting cement. The experimental powder was obtained by sol-gel process and then, it was used to prepare the experimental cements. The properties of cement pastes, such as setting time and working time, microhardness and diametral tensile strength were determined. Fluoride release from GICs was evaluated at time intervals of 1, 7, 14, 21 and 28 days in deionized water. Atomic force microscopy (AFM) analyses showed that the surface of the experimental cements is more homogeneous than commercial GICs. The mechanical properties and the measure of liberation of fluoride of the two cements were influenced by ratio powder:liquid and chemical composition of the precursor powders. Experimental cements released less fluoride than commercial cements. However, this liberation was more constant during the analyzed period. Thus, the results obtained in this study indicated that the composition of the experimental powder modified by the niobium can lead the formation of the polysalt matrix with good mechanical properties. In other words, we can say that experimental powder offered considerable promise for exploitation in dental field.

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Dental ceramics are presented within a simplifying framework allowing for facile understanding of their development, composition and indications. Engineering assessments of clinical function are dealt with and literature is reviewed on the clinical behaviour of all-ceramic systems. Practical aspects are presented regarding the choice and use of dental ceramics to maximize aesthetics and durability, emphasizing what we know and how we know it.

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Although visualization in the field of dentistry has some of the same requirements as the medicine field, the differences in goal demand specific approaches. This paper reports on the implementation of two fundamentally different approaches to reconstruction of structures from planar cross sections and their application to dentistry data. One of the approaches was an implementation of a distance-based sampling technique, and the other is a new algorithm, based on the Delaunay triangulation. Both were tested using contour data of teeth and the results are compared here in the light of the target applications, which are teaching and training dentistry, as well as simulation of dental procedures and illnesses. Widely mentioned problems encountered in local reconstruction methods such as marching cubes for these cases are clearly illustrated in this paper, and a very satisfactory alternative is given. © 2000 SPIE and IS&T.

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Titanium is a metallic element known by several attractive characteristics, such as biocompatibility, excellent corrosion resistance and high mechanical resistance. It is widely used in Dentistry, with high success rates, providing a favorable biological response when in contact with live tissues. Therefore, the objective of this study was to describe the different uses of titanium in Dentistry, reviewing its historical development and discoursing about its state of art and future perspective of its utilization. A search in the MEDLINE/PubMed database was performed using the terms 'titanium', 'dentistry' and 'implants'. The title and abstract of articles were read, and after this first screening 20 articles were selected and their full-texts were downloaded. Additional text books and manual search of reference lists within selected articles were included. Correlated literature showed that titanium is the most used metal in Implantology for manufacturing osseointegrated implants and their systems, with a totally consolidated utilization. Moreover, titanium can be also employed in prosthodontics to obtain frameworks. However, problems related to its machining, casting, welding and ceramic application for dental prosthesis are still limiting its use. In Endodontics, titanium has been used in association to nickel for manufacturing rotatory instruments, providing a higher resistance to deformation. However, although the different possibilities of using titanium in modern Dentistry, its use for prostheses frameworks still needs technological improvements in order to surpass its limitations. © 2012 Indian Prosthodontic Society.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Background. Reduced surface tension of liquids results in higher surface wetting ability and diffusivity by the substrate. Objectives. The objective of this study was to evaluate the influence of the Grander Technology in reducing the surface tension of adhesive systems. Methods. Two adhesive systems (self-etch and total-etch) were modified by physical contact with the Grander system Flexible unit to revitalize water, for 48 h. Surface tension of adhesive systems and water in normal and grander-modified conditions was measured with a goniometer. Results. The results showed a reduction of surface tension for all conditions grander-modified between 3-15%. Conclusions. Grander Technology was effective in reducing the surface tension of the Single Bond and Clearfil SE Bond adhesive systems. Clinical significance. Grander technology was employed to restructure the molecular structure of water-based adhesive systems, which can increase their wetness capacity and therefore ensure a greater diffusibility.

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This paper analyses the scientific collaboration network formed by the Brazilian universities that investigate in dentistry area. The constructed network is based on the published documents in the Scopus (Elsevier) database covering a period of 10 (ten) years. It is used social network analysis as the best methodological approach to visualize the capacity for collaboration, dissemination and transmission of new knowledge among universities. Cohesion and density of the collaboration network is analyzed, as well as the centrality of the universities as key-actors and the occurrence of subgroups within the network. Data were analyzed using the software UCINET and NetDraw. The number of documents published by each university was used as an indicator of its scientific production.

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Introduction and Objective: Photoelasticity consists of an experimental technique of stress analysis. This technique is very used in most different areas including Dentistry. This literature review presents the several applications of photoelastic technique in Dentistry the several applications of photoelastic technique in Dentistry as well as its advantages and disadvantages. Literature review: Based on this method of analysis, it is possible the verification of the stress distribution and deformation in structures with complex geometry as maxilla and mandible. It can be used to evaluate the distribution of stress on several types of prosthesis as removable partial denture systems with different retention systems, conventional implant prosthesis, overdentures and Brånemark protocols. Moreover, photoelasticity can be used to assess the stress generated by various by various orthodontic movements, different orthodontic systems and different materials (orthodontic wires). In addition, it is used to analyze different defects of maxillectomy, splint types on traumatized tooth and post-core restoration methods. This technique can also be used to assess dental instruments such as evaluation of different designs of periodontal probe. Conclusion: The photoelastic analysis has been a technique of great importance in health area studies, more specifically in Dentistry. Based on this method of analysis, it is possible to measure the stress distribution and deformation in structures with complex geometry as maxilla and mandible.