To treat a cavity your dentist will remove the decayed portion of the tooth and then "fill" the area on the tooth where the decayed material was removed. Fillings are also used to repair cracked or broken teeth and teeth that have been worn down from misuse (such as from nail-biting or tooth grinding). At Gateway Dental in Colleyville, Texas, Patricia Calabria, DDS, Andre Ellis, DDS, and their team, we will be happy to clarify any doubt, just contact the office to schedule your appointment.
First, the dentist will use a local anesthetic to numb the area around the tooth to be filled. Next, a drill, air abrasion instrument, or laser will be used to remove the decayed area. The choice of instrument depends on the individual dentist's comfort level, training, and investment in the particular piece of equipment as well as location and extent of the decay.
Next, your dentist will probe or test the area to determine if all the decay has been removed. Once the decay has been removed, the dentist will prepare the space for the filling by cleaning the cavity of bacteria and debris. If the decay is near the root, your dentist may first put in a liner made of glass ionomer, composite resin, or other material to protect the nerve. Generally, after the filling is in, your dentist will finish and polish it.
Several additional steps are required for tooth-colored fillings and are as follows. After your dentist has removed the decay and cleaned the area, the tooth-colored material is applied in layers. Next, a special light that "cures" or hardens each layer is applied. When the multilayering process is completed, the dentist will shape the composite material to the desired result, trim off any excess material, and polish the final restoration.
Today, several dental filling materials are available. Teeth can be filled with gold; porcelain; silver amalgam (which consists of mercury mixed with silver, tin, zinc, and copper); or tooth-colored, plastic, and materials called composite resin fillings. There is also a material that contains glass particles and is known as glass ionomer. This material is used in ways similar to the use of composite resin fillings.
The location and extent of the decay, cost of filling material, your insurance coverage, and your dentist's recommendation assist in determining the type of filling best for you.
Advantages of cast gold fillings:
Disadvantages of cast gold fillings:
Advantages of silver fillings:
Disadvantages of silver fillings:
The mercury contained in the amalgam releases low levels of mercury in the form of a vapor that can be inhaled and absorbed by the lungs. High levels of mercury vapor exposure are associated with adverse effects in the brain and the kidneys. Studies have found no link between the amalgam fillings and health problems and the FDA considers them safe for adults and children ages 6 and above.
Advantages of composites:
Disadvantages of composites:
In addition to tooth-colored, composite resin fillings, two other tooth-colored fillings exist -- ceramics and glass ionomer.
Indirect fillings are similar to composite or tooth-colored fillings except they are made in a dental laboratory and require two visits before being placed. Indirect fillings are considered when not enough tooth structure remains to support a filling, but the tooth is not so severely damaged that it needs a crown.
During the first visit, decay or an old filling is removed. An impression is taken to record the shape of the tooth being repaired and the teeth around it. The impression is sent to a dental lab that will make the indirect filling. A temporary filling (described below) is placed to protect the tooth while the restoration is being made. During the second visit, the temporary filling is removed, and the dentist will check the fit of the indirect restoration. Provided the fit is acceptable, it will be permanently cemented into place.
There are two types of indirect fillings -- inlays and onlays.
Inlays and onlays are more durable and last much longer than traditional fillings -- up to 30 years. They can be made of tooth-colored composite resin, porcelain, or gold. An onlay can be used to protect a weakened tooth because it can cover the top chewing surface and distribute the forces around the tooth like a crown.
Another type of inlay and onlay -- direct inlays and onlays -- follow similar processes and procedures as the indirect, but the direct is made in the mouth and can be placed in one visit. The type of inlay or onlay used depends on how much sound tooth structure remains and consideration of any cosmetic concerns.
Temporary fillings are used under the following circumstances:
Temporary fillings are just that; they are not meant to last. They usually fall out, fracture, or wear out within a month. Be sure to contact your dentist to have a temporary filling replaced with a permanent one. If you don't, the tooth could become infected or you could have other complications.
Over the past several years, concerns have been raised about silver-colored fillings, otherwise called amalgam fillings. Because these fillings contain the toxic substance mercury, some people think they are responsible for causing a number of diseases, including autism, Alzheimer's disease, and multiple sclerosis.
The American Dental Association (ADA), the FDA, and numerous public health agencies say there's no proof that dental fillings cause harm to consumers. The causes of autism, Alzheimer's disease, and multiple sclerosis remain unknown. Additionally, there is no solid, scientific evidence to back up the claim that if a person has amalgam fillings removed, they will be cured of these or any other diseases.
Although amalgams do contain mercury, when they are mixed with other metals, such as silver, copper, tin, and zinc, they form a stable alloy that dentists have used for more than 100 years to fill and preserve hundreds of millions of decayed teeth.
In June 2008, the FDA said, "Dental amalgams contain mercury, which may have neurotoxic effects on the nervous systems of developing children and fetuses."
And there's more. "Pregnant women and persons who may have a health condition that makes them more sensitive to mercury exposure, including individuals with existing high levels of mercury bioburden, should not avoid seeking dental care, but should discuss options with their health practitioner," according to the FDA.
The changes come in response to a lawsuit filed by consumer groups and individuals concerned about mercury exposure. To settle the suit, the FDA agreed to update its web site.
To maintain fillings, you should follow good oral hygiene -- visiting your dentist regularly for cleanings, brushing with a fluoride toothpaste, flossing and using an antibacterial mouthwash at least once daily. If your dentist suspects that a filling might be cracked or is "leaking" (when the sides of the filling don't fit tightly against the tooth, this allows debris and saliva to seep down between the filling and the tooth, which can lead to decay), they will take X-rays to assess the situation. If your tooth is extremely sensitive, if you feel a sharp edge, if you notice a crack in the filling, or if a piece of the filling is missing, call your dentist for an appointment.