RESUMO
The purpose of this paper was to observe changes occurred on the surface of some amalgams commonly found in the national market in order to evaluate tarnishing, darkening and corrosion on polished and non-polished surfaces. The method used was alternate immersion in bidestilled water, and 50% acetic acid, 14.5% lactic acid. A control, for comparative purposes, was not submitted to immersion but left in normal environmental conditions.
Assuntos
Amálgama Dentário/química , Acetatos , Cor , Corrosão , Polimento Dentário , Lactatos , Ácido Láctico , Propriedades de SuperfícieRESUMO
A wide variety of restoration materials for prosthetic odontology is now available to the dental surgeon, either of the covalent type (acrylic resins), metallic (alloys), ionic (porcelains), or a combination of them, as in the so-called composites, such as the composite resins, or as ceramics-metals mixtures. An example of the latter is a product called Miracle-Mix, a glass ionomere cement reinforced with an amalgam alloy. In those cases where the blend is done by a synterization process, the material is called Cermet. The above-listed alternatives clearly evidence day-to-day advances in odontology, with researchers and manufacturers engaged the world over in improving existing products or developing new ones to enrich the dentist's armamentarium. As a side effect of this constant renewal, those dentists who have failed to update their knowledge fall behind in their practice as they persist in using products they have known for years, and may be deceived by advertisements of too-often unreliable products. It is, therefore, important to be aware of available products and their latest improvements.
Assuntos
Ligas Metalo-Cerâmicas , Cerâmica , Ligas de Cromo , Corrosão , Ligas de Ouro , Dureza , PaládioRESUMO
Occurrences of phenomena such as creep, flow, proportional limit, yield or aqueous sorption, among others, are responsible for the success of failure of treatments performed in daily dental practice; their full understanding will allow the dentist to explain unexpected and undesirable performance of materials, instruments and equipment. With this purpose, the Standards for Dental Materials, Instruments and Equipment were created to specify the requirements these products must fulfill in order to assure an adequate performance. The first of these Standards is discussed in the present article, in view of its great clinical significance.