Mercury fillings have been used in dentistry since the Civil War era. They are an amalgam of 50% mercury, mixed with silver, copper, tin and other metals. Mercury fillings were invented as a cheap alternative to gold. Because they are easy to place and inexpensive, mercury fillings have been widely used for 150 years. So what is the controversy?
By volume, amalgam fillings contain over 50% mercury—one of the most toxic substances on earth.
Mercury amalgam technology is ancient by modern medical standards. Mercury amalgam was standardized for manufacture in 1895 and dentists have been using it to fill teeth for at least 160 years.
Mercury silver fillings do not bond (stick) to the tooth structure. This requires the dentist to wedge the filling into the tooth to keep it from falling out. However, creating this wedge effect requires the removal of excessive amounts of healthy tooth structure—weakening the tooth and predisposing it to cracks and fracture.
The lack of a bond between the filling and the tooth permits bacteria to leak underneath the filling. This creates decay that is often not detected until the tooth has been further damaged.
Just like in a thermometer, the mercury part of the filling expands and contracts. These expansion and contraction cycles wedge the tooth apart. Eventually the tooth will fatigue, crack and split. Repairing a cracked tooth usually requires either a root canal and/or a crown.
In contrast, modern tooth-colored restorations are adhesive, highly cosmetic, and mercury-free. These esthetic restorations are strongly bonded to the tooth using a state-of-the-art technique that intimately binds the material to the surrounding tooth structure. Using these advanced materials and techniques, we can restore the original health and beauty of the tooth.