Amalgam tooth fillings are materials used in dentistry to rebuild cavities in teeth. They are made of amalgam, an alloy of mercury with other metals such as silver, copper, tin and zinc. Amalgam is a durable and compressive material, making it a popular choice for tooth fillings, especially on molars. Amalgam fillings are also characterized by high wear resistance, and their use is relatively easy and quick. However, due to concerns about mercury toxicity, these fillings are increasingly being replaced by materials that are safer for the patient's health.