Amalgam – Four or More Surfaces, Primary or Permanent- Dental Procedure Code Description
A "filling" is a form of “direct” dental restoration used to repair a decayed, chipped, cracked or otherwise damaged tooth.
It is called a direct restoration because the material used to repair the tooth undergoes its hardening process while in “direct” contact with the tooth and inside the mouth. Other procedures such as inlays and onlays are considered to be “indirect” restorations because the material used to repair the tooth is created ”outside the mouth,” either in a lab by a dental technician, or via a computer-controlled milling machine.
In all, there are five surfaces of the tooth where a filling can be placed: the distal, occlusal, buccal, mesial, and lingual/palatal surfaces. Additionally, teeth are segmented into two major categories: anterior and posterior. Anterior, by definition, means “nearer the front,” so the teeth in the front of your mouth—up to and including your incisors—are considered to be anterior. The remaining teeth fall under the category of posterior, which means “further back in position, or nearer the rear.”
With this dental procedure code, a filling made from a mixed metal “alloy” of mercury, silver, tin, copper, and other metals, is used to repair damage on four surfaces of a posterior tooth. At times, this procedure can also be done on an anterior tooth if the surface is not readily visible within the “smile-zone.” A four-surface silver filling is typically undertaken when cavities are found on what is referred to as the “interproximal” surface of the tooth. Simply put, these are the surfaces that butt up against the surface of another tooth. Access is gained to these areas by drilling through the biting surface of the adjacent tooth.
Dental amalgam has a long history of use that can be traced at least as far back as the Tang Dynasty in 659 AD, but its rise to prominence as a preferred dental restorative truly began in the 1800's. Amalgam is durable, costs less than some other types of restoratives, and is long-lasting. It is also easy to place and hardens quickly, making it a good solution for filling large cavities that form deep in the tooth.
To prepare for a four-surface amalgam filling, a dentist will first remove any decayed or weakened areas of the tooth, and then use a variety of tools to prepare the tooth for the filling material. Depending on your situation, as well as the preferred procedures of your dentist, an amalgam filling may be secured with cement, or as is most common, by the further excavation of a recessed ridge cut beneath the remaining healthy portion of the tooth's biting surface. These “relief cuts” prevent the amalgam from falling out, and increase its retention and resistance to slipping. One such cut is a “dovetail” relief used similarly in woodworking.
Once the filling is layered in place, your bite will be checked to ensure all surfaces meet naturally with the new filling. Typically, after at least 24 hours, your dentist will then re-examine the filling, and shape and polish it to follow the natural contour of the tooth.