Silver Fillings Are Hazardous To Your Health
Although silver fillings (also known as "dental amalgam") can indeed last for a very long time, they are subject to corrosion and leakage when surrounded by oral fluids within the mouth. When silver fillings corrode, the seal of the filling with the existing tooth structure is compromised. The bacteria in our mouths that cause dental caries ("cavities") can sneak in between the corroded filling and tooth structure, and ultimately, set up a process of decay underneath the silver filling.
Another disadvantage to silver fillings is that they exhibit a biomechanical property called "creep". Creep is the slow expansion of a silver filling within a mineralized structure (such as a tooth), and after many years, can lead to microfractures within the tooth. If left unaddressed, creep ultimately causes large portions of the tooth to fracture, sometimes necessitating a root canal and crown.