RESUMO
The influence of mucin on the corrosion behaviour of seven typical dental casting alloys was investigated. A commercial saliva substitute (Saliva Orthana) containing mucin, and a control from which the mucin had been removed, were used. The electrochemical behaviour of the test alloys was evaluated around the open circuit potential (OCP) utilizing standard potentiodynamic techniques, as a function of oxygen concentrations and pH. The results of the corrosion measurements were analysed by a four-way ANOVA to detect the influence of alloy, environment and possible interactions. Mucin seems to act as a cathodic inhibitor at pH 6.7 but not at pH 4.6. An unidentified component (e.g. benzoate) of the saliva substitute probably acts as an adsorption inhibitor. Anodic passivation is also correlated with the artificial saliva composition.
Assuntos
Ligas Dentárias , Mucinas/fisiologia , Análise de Variância , Corrosão , Condutividade Elétrica , Eletroquímica , Concentração de Íons de Hidrogênio , Oxigênio , Saliva ArtificialRESUMO
In a methodological investigation colour slides were used for the clinical evaluation of crowns. Four criteria, described in a criteria list or recorded by means of reference slides, were used. In assessing the clinical characteristics of crowns to a certain extent colour slides turned out to be a useful instrument. Shortcomings of the method are discussed and improvements are suggested.
Assuntos
Recursos Audiovisuais , Coroas , Fotografação , Dente Pré-Molar , Estudos de Avaliação como Assunto , Gengiva/anatomia & histologia , Humanos , Dente Molar , Abrasão Dentária/patologiaRESUMO
The ADA specification method for preparation of amalgam samples for tensile strength studies has been investigated. It was determined as being of acceptable reliability for comparison against normal clinical use of the material.