Amalgam fillings are made by combining certain metals and have been widely used for decades. They are durable and cost-effective, making them a common choice for molars and premolars, where strength is essential. However, they are less commonly used for visible teeth due to their metallic appearance. While amalgam contains small amounts of mercury, it is considered safe for most patients. However, it may not be recommended for pregnant or lactating women, children, or individuals with kidney conditions.