Reabilitação estética de diastemas anterossuperiores com resina composta após abordagem ortodôntica

Smile, besides being an important factor in the self-esteem of human, has been considered the “ateway” to many opportunities today. However, there are some changes can be found and which can provide the aesthetic, functional and psychological impairment of the individual, like the diastema, defined by a spacing between adjacent teeth. Objectives: thus, we intend to show through a case an aesthetic rehabilitation of a young patient with the presence of diastema anterosuperiores teeth using composite resin of direct insertion and minimal wear of dental structure. Results: the result was extremely satisfying for both, the patient and the professional, proving the efficiency of composite resins in cases of rehabilitation when well indicated. Conclusion: thus, with the increase in the quality of technical and aesthetic materials, the use of this, subsequent to orthodontic treatment in patients who still show gaps between the teeth, provides ease and security to the professional in performing the procedure, obtaining better results. Smile, besides being an important factor in the self-esteem of human, has been considered the “ateway” to many opportunities today. However, there are some changes can be found and which can provide the aesthetic, functional and psychological impairment of the individual, like the diastema, defined by a spacing between adjacent teeth. Objectives: thus, we intend to show through a case an aesthetic rehabilitation of a young patient with the presence of diastema anterosuperiores teeth using composite resin of direct insertion and minimal wear of dental structure. Results: the result was extremely satisfying for both, the patient and the professional, proving the efficiency of composite resins in cases of rehabilitation when well indicated. Conclusion: thus, with the increase in the quality of technical and aesthetic materials, the use of this, subsequent to orthodontic treatment in patients who still show gaps between the teeth, provides ease and security to the professional in performing the procedure, obtaining better results.O sorriso, além de ser um importante fator na autoestima do ser humano, atualmente tem sido considerado a “porta de entrada” para muitas oportunidades. Nesse contexto, existem algumas alterações que podem gerar o comprometimento estético, funcional e psicológico do indivíduo, sendo uma delas o diastema, definido pela presença de espaçamento entre os dentes adjacentes. Objetivos: mostrar, por meio de um caso clínico, uma reabilitação estética direta em paciente jovem com presença de diastemas nos dentes anterossuperiores. Materiais e métodos: realizou-se a reanatomização com resina composta Empress Direct de inserção direta, empregando o auxílio de guia palatina feita em silicone, ocasionando o mínimo de desgaste da estrutura dental. Resultados: o resultado foi satisfatório, tanto para o paciente quanto para o profissional, comprovando a eficiência das resinas compostas em casos de reabilitação, quando bem indicadas. Conclusão: com o aumento na qualidade das técnicas e dos materiais estéticos diretos, seu uso subsequente ao tratamento ortodôntico – caso os pacientes ainda apresentem espaçamentos entre os dentes – proporciona facilidade e segurança ao profissional na realização do procedimento, obtendo ótimos resultados

Mechanical Behavior of Different Restorative Materials and Onlay Preparation Designs in Endodontically Treated Molars

This study evaluated the effect of the combination of three different onlay preparation designs and two restorative materials on the stress distribution, using 3D-finite element analysis. Six models of first lower molars were created according to three preparation designs: non-retentive (nRET), traditional with occlusal isthmus reduction (IST), and traditional without occlusal isthmus reduction (wIST); and according to two restorative materials: lithium-disilicate (LD) and nanoceramic resin (NR). A 600 N axial load was applied at the central fossa. All solids were considered isotropic, homogeneous, and linearly elastic. A static linear analysis was performed, and the Maximum Principal Stress (MPS) criteria were used to evaluate the results and compare the stress in MPa on the restoration, cement layer, and tooth structure (enamel and dentin). A novel statistical approach was used for quantitative analysis of the finite element analysis results. On restoration and cement layer, nRET showed a more homogeneous stress distribution, while the highest stress peaks were calculated for LD onlays (restoration: 69-110; cement layer: 10.2-13.3). On the tooth structure, the material had more influence, with better results for LD (27-38). It can be concluded that nRET design showed the best mechanical behavior compared to IST and wIST, with LD being more advantageous for tooth structure and NR for the restoration and cement layer

Computer Aided Design Modelling and Finite Element Analysis of Premolar Proximal Cavities Restored with Resin Composites

This study evaluated the stress distribution in five different class II cavities of premolar models restored with conventional or bulk-fill flowable composite by means of finite element analysis (FEA) under shrinkage and occlusal loading. An upper validated premolar model was imported in the software, and five class II cavities with different occlusal extensions and dimensions were prepared: horizontal cavity on the mesial surface (horizontal slot), mesio-occlusal cavity, mesial cavity (vertical slot), tunnel type cavity and direct access cavity. The models were restored with conventional or bulk-fill flowable resin composite. The tested materials were considered as homogeneous, linear, and isotropic. The Maximum Principal Stress criteria was chosen to evaluate the tensile stress results. The lowest shrinkage stress value was observed in the direct access cavity restored with bulk-fill flowable resin composite (36.12 MPa). The same cavity, restored with conventional composite showed a score of 36.14 MPa. The horizontal slot cavity with bulk-fill flowable showed a score of 46.71 MPa. The mesio-occlusal cavity with bulk-fill flowable had a score of 53.10 MPa, while with conventional composite this was 55.35 MPa. Higher shrinkage stress was found in the vertical slot cavity with conventional resin 56.14 MPa, followed by the same cavity with bulk-fill flowable 56.08 MPa. Results indicated that the use of bulk-fill flowable composite resin more significantly decreased the polymerization shrinkage stress magnitude. The larger the cavity and the volume of material necessary to restore the tooth, the greater the residual stress on enamel and dentin tissue

Effect of biologically oriented preparation technique on the stress concentration of endodontically treated upper central incisor restored with zirconia crown: 3d-fea

The aim of this study was to evaluate the effect of biologically oriented preparation technique on the stress concentration of endodontically treated upper central incisors restored with zirconia crown (yttria-stabilized zirconia polycrystalline ceramic) through finite element analysis (FEA). Four models of maxillary central incisors containing enamel, dentin, periodontal ligament, cortical and medullary bone were created in CAD. Each model received a polymeric core-build up with nanofilled dental resin composite. The evaluated models were SM—preparation in shoulder 90°; CM—chamfer preparation; BOPT—biologically oriented preparation technique and BOPTB—BOPT preparation 1 mm below the cement-enamel junction. All models received zirconia crowns (5Y-TZP), fiberglass post and 1 mm ferrule. The models were imported into the analysis software with parameters for mechanical structural testing using the maximum principal stress and the tensile strength as the analysis criteria. Then, load of 150 N was applied at the cingulum with 45° slope to the long axis of the tooth, with the fixed base for each model. The type of marginal preparation affected the stresses concentration in endodontically treated teeth and in the zirconia crown margin. Considering the stress magnitude only, BOPT is a viable option for anterior monolithic zirconia crowns; however, with the highest stress magnitude at the restoration margin

Influence of Polymeric Restorative Materials on the Stress Distribution in Posterior Fixed Partial Dentures: 3D Finite Element Analysis

This study evaluated the effect of interim restorative materials (acrylic resin (AR), resin composite (RC) or polyetheretherketone (PEEK) for dental computer-aided design/computer-aided manufacturing (CAD/CAM)) on the stress distribution of a posterior three-unit fixed partial denture

PROJETO RONDON NACIONAL – UMA LIÇÃO DE VIDA E CIDADANIA

PONTIFICIA UNIVERSIDADE CATÓLICA DO RIO GRANDE DO SU

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema