Since the 1800s the material of choice for dental fillings has been amalgam, due to its low cost, ease of application, strength and durability. However, Dental Amalgam has certain unfavourable characteristics, including its metal colour, amalgam toxicity (mercury comprises 50% of amalgam) and environmental threat.
Amalgam also has the tendency to expand and contract with temperature changes in the mouth, causing fillings to crack, become loose and threaten the structural integrity of the surrounding tooth.