Amalgam or silver-colored fillings: Dental amalgam is considered a safe, affordable and durable material that has been used to restore the teeth of more than 100 million Americans. It contains a mixture of metals such as silver, copper and tin, in addition to mercury, which binds these components into a hard, stable and safe substance. Dental amalgam has been studied and reviewed extensively, and has established a record of safety and effectiveness.
The current use of amalgam has not posed a health risk apart from allergic reactions in few patients. Clinical justifications have not been available for removing clinically satisfactory amalgam restorations, except in patients allergic to amalgam constituents. Mercury hypersensitivity is an immune response to very low levels of mercury. There is no evidence that mercury released from amalgams results in adverse health effects in the general population. If the recommended mercury hygiene procedures are followed, the risks of adverse health effects in the dental office could be minimized. Amalgam is safe and effective restorative material and its replacement by non-amalgam restorations is not indicated. Also a recent review by the American Dental Association Council on Scientific Affairs states that: “Studies continue to support the position that dental amalgam is a safe restorative option for both children and adults. When responding to safety concerns it is important to make the distinction between known and hypothetical risks.”
Composite or non-metal filling: Dental composite resins (better referred to as "resin-based composites" or simply "filled resins") are types of synthetic resins which are used in dentistry as restorative material or adhesives. Dental composite resins have certain properties that will benefit patients according to the patient's cavity. It has a micro-mechanic property that makes composite more effective for filling small cavities where amalgam fillings are not as effective and could therefore fall out (due to the macro-mechanic property of amalgam). Synthetic resins evolved as restorative materials since they were insoluble, of good tooth-like appearance, insensitive to dehydration, easy to manipulate and reasonably inexpensive.