If you've been told you need a dental filling, you're not alone: 92% of Americans have had at least one cavity. Dental fillings are the tried-and-true treatment for treating cavities – and they come in a variety of options to suit every need. Dental fillings can be made of silver amalgam, composite, porcelain and even gold. Composite fillings, which are made of a tooth-colored plastic and glass composite, are quickly becoming the preferred dental filling due to their natural appearance and durability. The type of dental filling used is determined by a number of factors, including size and location of the cavity, as well as your budget.