Fillings, or restorations, include amalgam, composite. gold, and porcelain. Several factors influence the choice, performance, durability, and expense of dental restorations. These include:
- the components of the filling material
- the amount of tooth structure remaining
- where and how the filling is placed
- the chewing load that the tooth will have to bear
- the length and number of visits needed to prepare and finish the restoration
There are two basic types of dental fillings--direct and indirect.
Direct fillings are fillings that are placed immediately into the cavity after the dentist prepares it, so it is completed in one appointment.
Traditional amalgam (silver) fillings have been used for over 150 years. The strength and durability of these fillings make them useful for situations where teeth must withstand strong forces from chewing, such as the molars in the back of the mouth. Depending on the size of the filling, many have lasted for 20, even 30 years or more. Amalgam fillings depend upon mechanical retention to hold them in so the tooth needs to be undercut and removed to a certain depth. Two main advantages of amalgam fillings art they are generally less expensive than other types of fillings and they can be placed in less than ideal conditions where moisture cannot be eliminated such as under the gums or in deep cavities.
Newer dental fillings called composites or composite resins mimic the natural appearance of teeth. They have been used generally in the front of the mouth where esthetics is a concern, but now they can also be used on back teeth, depending on the location and extent of the decay.The longevity and durability of composites has increased over time, but it is still not as good as amalgam fillings.This means that they will need to be replaced more often. Because composite fillings are chemically bonded to the tooth, less tooth removal is often required. Composites must be placed in a very well-controlled area with no saliva contamination or moisture. If this does not occur, they are more subject to leakage and recurringt decay. Two main disadvantages of composite fillings is that generally they are 1/3 more expensive than amalgam fillings and they can be much more sensitive.
Indirect fillings include gold and porcelain inlays and involve a two visit procedure. The dentist prepares the tooth and takes an impression of it to send to the lab technician who will custom make the inlay. On the second appointment,usually in two weeks, the dentist fits the inlay and cements or glues it onto the tooth. Although these are more expensive, they can last and look beautiful for a lifetime. The advantage of these is that the dentist and lab technician have complate control over the design and fit. This is very helpful in areas with larger spaces between the teeth or where there are tipped or rotated teeth, for example. The biggest advantage of porcelain is that it mimics natural tooth appearance. The advantage of gold is that it is very biocompatible and wears the same as natural teeth.