What is a Filling?
A filling is a way to restore a tooth damaged by decay back to its normal function and shape. When a dentist gives you a filling, he or she first removes the decayed tooth material, cleans the affected area, and then fills the cleaned out cavity with a filling material.
By closing off spaces where bacteria can enter, a filling also helps prevent further decay. Materials used for fillings include gold, porcelain, a composite resin (tooth-colored fillings), and an amalgam (an alloy of mercury, silver, copper, tin and sometimes zinc).
How Do I Know if I Need a Filling?
Only your dentist can detect whether you have a cavity that needs to be filled. During a checkup, your dentist will use a small mirror to examine the surfaces of each tooth.
Anything that looks abnormal will then be closely checked with special instruments. Your dentist may also X-ray your entire mouth or a section of it. The type of treatment your dentist chooses will depend on the extent of damage caused by decay.
What is a Composite Resin (White Filling)?
A composite filling is a tooth-colored plastic and glass mixture used to restore decayed teeth. Composites are also used for cosmetic improvements of the smile by changing the color of the teeth or reshaping disfigured teeth.
How is a composite placed?
Following preparation, the dentist places the composite in layers, typically using a light specialized to harden each layer. When the process is finished, the dentist will shape the composite to fit the tooth. The dentist then polishes the composite to prevent staining and early wear.
What are the advantages of composites?
Aesthetics are the main advantage of composites, since dentists can blend shades to create a color nearly identical to that of the actual tooth. Composites bond to the tooth to support the remaining tooth structure, which helps to prevent breakage and insulate the tooth from excessive temperature changes.
What are the disadvantages?
After receiving a composite, a patient may experience postoperative sensitivity. Also, the shade of the composite can change slightly if the patient drinks tea, coffee or other staining foods. The dentist can put a clear plastic coating over the composite to prevent the color from changing if a patient is particularly concerned about tooth color. Composites tend to wear out sooner than silver fillings in larger cavities, although they hold up as well in small cavities.
What is dental amalgam?
Dental amalgam is a dental filling material used to fill cavities caused by tooth decay.
It has been used for more than 150 years in hundreds of millions of patients around the world.
Dental amalgam is a mixture of metals, consisting of liquid (elemental) mercury and a powdered alloy composed of silver, tin, and copper. Approximately 50% of dental amalgam is elemental mercury by weight. The chemical properties of elemental mercury allow it to react with and bind together the silver/copper/tin alloy particles to form an amalgam.
Dental amalgam fillings are also known as “silver fillings” because of their silver-like appearance. Despite the name, "silver fillings" do contain elemental mercury.
When placing dental amalgam, the dentist first drills the tooth to remove the decay and then shapes the tooth cavity for placement of the amalgam filling. Next, under appropriate safety conditions, the dentist mixes the powdered alloy with the liquid mercury to form an amalgam putty. (These components are provided to the dentist in a capsule as shown in the graphic.) This softened amalgam putty is placed and shaped in the prepared cavity, where it rapidly hardens into a solid filling.