RESUMEN
Although the rate of lower limb amputation in patients with diabetes is decreasing, amputation still remains a major complication of diabetes. Prosthetics have been long used to help amputees ambulate. The last decade has seen many advances in prostheses with the enhanced understanding of the mechanics of ambulation and improved use of technology. This review describes the different types of prosthetic options available for below knee, ankle, and foot amputees, emphasizing the latest advances in prosthetic design.
Asunto(s)
Amputación Quirúrgica , Miembros Artificiales , Pie Diabético/cirugía , Pierna , Diseño de Prótesis , HumanosRESUMEN
Amalgam restorations, when first placed, have been shown to exhibit a gap at the amalgam/tooth interface. With time in service, this gap fills with corrosion products that have the potential to "seal" the restoration. With the advent of high-copper, more corrosion-resistant amalgams, there has been concern that the time required to create this seal would be increased significantly when compared with low-copper traditional amalgams. The current study was designed to address this concern. Amalgam was condensed into a MACOR mold, simulating a Class I cavity form and then immersed into a 1.0% NaCl solution to simulate oral conditions. Using an air pressure test, the sealing was monitored over time. The results showed that the sealing was influenced by the size of the initial gap prior to immersion as well as corrosion resistance of the amalgam and that a corrosion-resistant amalgam with a small initial gap size can seal as quickly as a corrosion-prone amalgam. Therefore, it is not possible to predict sealing behavior based on corrosion resistance, alone. Furthermore, the presence of zinc in the amalgam alloy has been shown to result in the formation of zinc corrosion products in the amalgam/mold margin, which contributes to more rapid sealing. Analysis of a tooth extracted after 16 years of clinical service that had been restored with an amalgam-containing zinc was also shown to contain zinc corrosion products in the occlusal marginal area. This could explain the reported reduction in marginal fracture of clinically placed amalgam restorations made from zinc-containing alloys.
Asunto(s)
Amalgama Dental/química , Adaptación Marginal Dental , Restauración Dental Permanente , Aleaciones/química , Cerámica/química , Cobre/química , Corrosión , Aleaciones Dentales/química , Preparación de la Cavidad Dental/clasificación , Humanos , Inmersión , Ensayo de Materiales , Modelos Dentales , Cloruro de Sodio/química , Propiedades de Superficie , Zinc/químicaAsunto(s)
Amputación Quirúrgica , Miembros Artificiales , Prótesis de la Rodilla , Diseño de Prótesis , Pie , Humanos , PiernaRESUMEN
OBJECTIVES: The aim of this study was to determine the effect of aqueous liquid films on Hg emission from of dental amalgam. METHODS: Amalgam specimens (4 mm dia. x 4 mm long) made from ten alloys were uniformly abraded on wet ASTM 600 grit SiC paper, quickly dried and covered by liquid films of a thickness that approximated the thickness of saliva films on tooth surfaces in vivo. Distilled water and two formulations of artificial saliva were tested. After abrasion and film placement, the specimens were immediately inserted in a plastic tube which was then closed. After 30 min, the Hg vapor that had collected in the tube was measured using a Jerome 411Hg analyzer. Hg emission from abraded surfaces exposed to air was also measured and used for comparative purposes. The test results were compared using ANOVA and Tukey's contrast test (p=0.05). RESULTS: Hg emission from abraded surfaces under liquid films was one to two orders of magnitude less than Hg emission from abraded surfaces exposed to air. SIGNIFICANCE: In vitro measurement of Hg vapor emission from abraded surfaces exposed to air should not be used to estimate directly the Hg vapor release from dental amalgam restorations in vivo.