All hard-milling CAD/CAM materials, that is, fully sintered, should be only hand polished. The glaze step can be suppressed resulting in time saving. However, the glaze step in soft-milling lithium disilicate is imperative.

Data de entrada do artigo: 03/03/2013 Data de aceite do artigo: 04/11/2013 Introdução: As próteses sobre implantes permitem diferentes opções para resolução de casos nos quais os pacientes apresentam edentulismo parcial ou total. A escolha entre prótese implantossuportada parafusada ou cimentada ainda gera dúvidas referentes à melhor alternativa para resolução dos casos clínicos. Objetivo: Este estudo visa destacar indicações, vantagens, desvantagens e limitações, além de abordar reversibilidade, distribuição de tensões, facilidade de confecção, estética, passividade e custo de cada sistema de conexão implante-prótese. Métodos: Os dados levantados foram artigos publicados durante os anos de 2000 a 2012 na Literatura Internacional em Ciências da Saúde (MedLine), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e no Scientific Eletronic Library Online (SciELO). Resultados: Percebe-se que ambas as técnicas apresentam prós e contras para suas indicações. A decisão pode ser realizada pelo profissional ou de acordo com o interesse do paciente, porém algumas situações clínicas específicas determinam a indicação de uma ou outra opção. Conclusão: Basear-se em um adequado planejamento e prognóstico do caso clínico torna-se fundamental para o sucesso a longo prazo da reabilitação com implantes dentários. Certamente, mais estudos são necessários para definir critérios mais fiéis para escolha entre as próteses sobre implantes parafusadas ou cimentadas.. Palavras-chave: implantes dentários; próteses e implantes; porcelana dentária. ResuMOIntroduction: There are different options to resolve cases in partially and totally edentulous patients with implant restorations. The choice of screw or cement-retained implant restorations still generates doubts about the best alternative for resolution of the clinical cases. Objective: This study aims to highlight indications, advantages, disadvantages and limitations, as well as reversibility, stress distribution, ease of fabrication, aesthetic, passive fit and cost of each implant-prostheses connection system. Methods: Data were articles published during the years 2000 to 2012 in the International Literature on Health Sciences (MedLine), Latin American and Caribbean Health Sciences (LILACS) and Scientific Electronic Library Online (SciELO). Results: It is clear that both techniques have their pros and cons for indications. The decision can be performed by professional or according to the patient's interest, however some specific clinical situations determine the indication of either option. Conclusion: Based on an adequate planning and prognosis of clinical case becomes critical to successful long-term rehabilitation with dental implants. Certainly, more studies are needed to define criteria for choosing the most faithful between screw or cement-retained implant restorations.

Abstract:The aim of this study was to determine the influence from the recovering time on the dimensional stability of polydimethylsiloxane (Speedex, Coltène/Whaledent Company, Altstätten, Switzerland) prior to type IV dental stone pouring. The double impression technique was utilized with uniform spacing of 1 mm for the wash paste, at 30 minutes, 24 hours and 72 hours after making the impression using an individual perforated metal tray. After the preparation of the impressions, six stone models were made by the standard procedure for all the impressions. The dimensional alterations (mm) of the models obtained were submitted to analysis of variance (ANOVA) and Tukey's test (α = 0.05). No statistically significant difference between the three groups (30 minutes, 24 hours and 72 hours) were recorded for either the height or diameter of the samples. However, upon comparing the results of the three groups with the metal standard model, there was a significant difference between group 1 (30 min) in relation to the diameter of the standard metal die (p = 0,047). The condensation silicone Speedex shows satisfactory dimensional stability, where dental stone models can be poured with assurance up to 72 hours after preparation of the impression.

Objectives Natural extracts have been investigated as a biomimetic strategy to mechanically strengthen the collagen network and control the biodegradation of extracellular matrix. This study evaluated the effect of epigallocatechin-3-gallate (EGCG) on abfraction lesions prior to the composite resin. Materials and Methods The sample consisted of 30 patients (aged between 28 and 60 years) with abfraction lesions located in 2 homologous premolars. The teeth were randomly assigned according to dentin treatment: 0.02% EGCG solution or distilled water (control). After enamel acid etching, the solutions were applied immediately for 1 minute. The teeth were restored with Universal Adhesive (3M) and Filtek Z350 XT (3M). Analyzes were done by 2 independent examiners using modified USPHS (retention, secondary caries, marginal adaptation, and postoperative sensitivity) and photographic (color, marginal pigmentation, and anatomical form) criteria at baseline (7 days) and final (18 months). The data analysis used Friedman and Wilcoxon signed-rank tests (α = 0.05). Results At baseline, all restorations were evaluated as alpha for all criteria. After 18 months, restorations were evaluated as alpha for secondary caries, color, and marginal pigmentation. There was significant difference between baseline and 18 months ( p = 0.009) for marginal adaptation and postoperative sensitivity ( p = 0.029), but no significant difference were verified between treatments ( p = 0.433). The EGCG group had a restoration retention rate of 93.3%, while the control group had 96.7%. Conclusions The application of EGCG solution on abfraction lesions did not significantly influence the survival of the restorations based on clinical and photographic criteria.