CAVITY FILLINGS: AMALGAM vs. COMPOSITE

Dental amalgam is a stable alloy made by combining elemental mercury, silver, tin, copper and possibly other metallic elements. Although dental amalgam continues to be a safe, commonly used restorative material, some concern has been raised because of its mercury content. However, the mercury in amalgam combines with other metals to render it stable and safe for use in filling teeth. It is durable, easy to use, highly resistant to wear and relatively inexpensive in comparison to other materials. For those reasons, it remains a valued treatment option for dentists and their patients.

Disadvantages of amalgam include possible short-term sensitivity to hot or cold after the filling is placed. The silver-colored filling is not as natural looking as one that is tooth-colored, especially when the restoration is near the front of the mouth, and shows when the patient laughs or speaks. And to prepare the tooth, the dentist may need to remove more tooth structure to accommodate an amalgam filling than for other types of fillings.

The amalgam is not really attached to the sides of the hole so when the tooth is stressed as in chewing or grinding, the tooth can flex away from the filling. Little cracks begin to develop. Like a crack in a car windshield, with each successive stress, the crack gets longer until part of the tooth falls off.

Composite fillings are a mixture of glass or quartz filler in a resin medium that produces a tooth-colored filling. They are composed of an organic polymer known as bisphenol-aglycidyl methacrylate (BIS-GMA), and inorganic particles such as quartz, borosilicate glass, and lithium aluminum silicate. They are sometimes referred to as composites or filled resins. Composite fillings provide good durability and resistance to fracture in small-to-mid size restorations that need to withstand moderate chewing pressure. Less tooth structure is removed when Dr. Takamatsu prepares the tooth, and this may result in a smaller filling than that of an amalgam. Composites can also be "bonded" or adhesively held in a cavity, often allowing Dr. Takamatsu to make a more conservative repair to the tooth.