Cavity Fillings Cavity filling is biocompatible material used for filling up the cavities. These cavities are prepared in a scientific & principled manner to achieve strong and a long lasting filling.
The main idea of preparing a cavity is to remove the infected position of the tooth so as to prevent the further spread of decay and hence the ultimate loss of the tooth.
The cavities are prepared using high speed drilling equipment, which is controlled by the dentist. Patient may not have any discomfort initially but as the drill bit move closer to the center of the tooth (where the nerves are located), the patient begins to experience sensitivity. This can be avoided if tooth is anesthetized, which of course means having to take an injection
If the cavity prepared is very deep, a layer of medicated cement is used to line the floor of the cavity to help in healing of the tissue.
In case of metal based filling material a base is given. This base is nothing but a thick coat of cement lining the floor of the cavity. The base not only adds to the strength of the over lying filling but also insulates the tooth from sharp variation in temperature, caused by the increased thermal conductivity of the metal filling.
The term cement, which is frequently used, is a mix of a chemical powder and liquid. This mix, which is initially soft, turns hard over a period of time resembling the common cement used for construction
For cavity preparation, which is not very deep, a cement base may not be required.
Filing of a prepared cavity depends upon a lot of factor such as.
Site (for an anterior tooth a metal filling may not be acceptable)
Function of a tooth (A posterior tooth might require a very strong filing to withstand the forces produced while chewing food)
Amount of remaining tooth structure: Too much of a hard filling material and very little amount of remaining tooth structure can cause the fracture of the tooth.
Type of material used to fill the opposing tooth( when two different metals are used to restore two opposing teeth small amounts of galvanic currents are produced which can be painful for the patient.
Filling materials can be of 2 types Tooth colored - Glass inomer, composites etc.
Non tooth colored - Amalgam, Gold
Each material has its own advantages for e.g. Amalgam is much more strong & tougher than the tooth colored composite hence ideal for posterior teeth where as composite filling material require very little cavity preparation and hence saves a lot of tooth cutting there by preserving as much natural tooth material as possible.