Resumo Introdução Recentemente, vêm surgindo no mercado alguns alginatos de armazenamento prolongado. Não há, no entanto, um consenso na literatura a respeito da estabilidade dimensional destes materiais durante este armazenamento Objetivo Avaliar, por meio de método prático experimental, a estabilidade dimensional de um alginato de armazenamento tardio. Material e método O material de moldagem utilizado foi o alginato Hydrogum 5 (Zhermack). Uma matriz metálica cilíndrica foi utilizada para a realização das moldagens, com 38 mm de diâmetro externo, 30 mm de diâmetro interno e cuja superfície superior apresenta três linhas paralelas entre si com 25 mm de comprimento e 20, 50 e 75 µm de largura. Após o tempo de geleificação do material de moldagem, 16 moldes foram colocados em um umidificador e essas amostras foram fotografadas utilizando-se uma câmera digital (Canon EOS Rebel 3Ti, Canon) associada a um software para análise das imagens obtidas (ImageJ 1.52a, U.S. National Institutes of Health; DI). A calibragem da régua foi 10 cm e, posteriormente, três linhas foram medidas três vezes, para se obter uma média dos comprimentos das linhas. As amostras foram fotografadas nos seguintes intervalos: imediatamente, 24, 48, 72, 96 e 120 horas. Resultado Os dados mostraram diferenças estatisticamente significantes para o fator tempo quando comparada a leitura imediata com os demais períodos de tempo de leitura (p<0,001) e quando comparada a leitura após 24 h de armazenagem com os demais períodos de tempo (p<0,001). Não houve diferença estatística (p>0,05) quando os tempos de armazenamento de 48 h, 72 h, 96 h e 120 h foram comparados entre si. Todos os valores encontravam-se dentro dos valores preconizados pela ISO 21563:2013. Conclusão Os moldes dos alginatos testados podem ser armazenados por até cinco dias em 100% de umidade relativa.

Digital planning of the prosthesis associated with surgical planning increased predictability, since surgical guides indicate the best place for implant installation, thus reducing the number of complications, and the CAD/CAM system provides predictability in the preparation of final restorations, according to the procedure previously planned. Our study reported a digital workflow used for the guided installation of two dental implants in regions 14 and 16, extraction of tooth 15 and installation of a fixed prothesis over implants. After anamnesis and clinical evaluation, intra- and extra-oral photographs of the patient were performed, molding the upper arch with polyvinylsiloxane (2-step putty/light-body technique) and requesting computed tomography. The plaster model obtained was sent to the laboratory and scanned. The generated file (STL) was used to create a diagnostic wax-up that was aligned to the tomography (in DICOM format), enabling the three-dimensional planning of the implants, which generated a partial printed surgical guide after approval of the dentist. After six months, the patient received the provisional fixed prosthesis printed in PMMA (polymethylmethacrylate) on an intermediate in PEEK (polyetheretherketone) aiming to condition an emergency profile to receive a definitive prosthesis two months later, with zirconia-milled infrastructure on a ti-base. The correct understanding of the operator about the steps of the digital workflow (diagnosis, prosthetic planning, surgical planning, guide preparation, temporary and final restorations) gives the operator improved predictability at the time of surgery as well as satisfactory aesthetic and functional result of definitive restorations.

Introduction: The discovery of titanium osseointegrated implants enabled the development of screw or cement-retained dental prostheses. However, each retention method involves different aspects. Objective: this study aims at reviewing the literature of in vitro and in vivo studies of the last 7 years on the mechanical, biological, aesthetic and occlusal properties and the cost of screw and cementretained prostheses to identify what can promote greater longevity and economy by considering the patient's clinical framework. Data sources: Our method was based on the collection of scientific articles published in English from 2012 to 2018 in the PubMed database. Summary of the findings: we noted that in some clinical cases, a retention method was more appropriate than the other, as seen in the access to the posterior region or the palatal face of the crowns, the position/ angulation of implants in the anterior region, the patient's health and economic conditions. Both protheses can suffer or not from mechanical and biological complications. Reversibility can also be associated to cement-retained protheses. There are alternatives to screwed prosthetics to achieve satisfactory aesthetics in the anterior region despite being more expensive. Ideal occlusion tends to be more easily achieved by cemented prosthesis as it avoids prosthetics screws and the formation of crown holes, despite the contributions of correct planning followed by the analysis of static and in motion occlusions. Conclusion: each retention method has its advantages and disadvantages. Therefore,the best method is the one that best fits the characteristics and needs of each patient.