Treating Cavities in Permanent Teeth

Today, tooth decay remains one of the most widespread diseases in the world. It is a disease process whereby bacteria in the mouth interacting with fermentable carbohydrate, mainly sugar, produce acids which can progressively break down hard tooth structure and penetrate enamel, dentin and eventually the nerve tissue of the tooth. If left untreated the disease may cause a cavity (hole in the tooth), pain, death of the nerve tissue, loss of the tooth, infection in the surrounding tissues and rarely death of an individual. 

In reality, tooth decay is rarely uniformly progressive and is more of a dynamic process which can be modified and arrested by changing the diet and adopting preventive measures. The most important preventive measure is keeping fluoride at a certain minimum level in saliva close to the tooth surface, where it continually hardens and rehardens the outside surface of the tooth. This works very well on the smooth surfaces of the teeth. Fluoride in water and in toothpaste helps to achieve this. On the biting surfaces of the teeth, the grooves and fissures are more difficult to keep clean, so a hard plastic or glass like material called Fissure Sealant was developed to prevent dental decay on these sites. These can be used on the permanent molar teeth of children or adults, who are considered high risk for developing dental decay. So, what are the options when preventive methods have failed, and tooth decay has taken hold in the form of a cavity in a tooth? 

White Composite Filling

As a general rule, it makes more sense to fill a small cavity in a permanent tooth with a white composite filling material. Less drilling is required, and more tooth substance can be preserved than for a silver filling of the same size. There is also the added advantage of being able to fissure seal the surrounding grooves and fissures at the same time as the filling is being placed. Even for larger cavities, white fillings are being used by the majority of dentists. The newer materials can match tooth colour almost to perfection. Composite adhesive filling technology is now so adaptable that this type of filling can be used in a whole variety of situations with confidence and predictability. The main drawbacks are the time and the high level of precision and skill that are required to place this type of restoration successfully. 

Silver Amalgam Fillings

These are very durable and provide great service over a long period. The material is less technique sensitive and can be placed much more quickly than composite and is therefore less expensive. These fillings are still being used to treat large cavities in back molar teeth when it is not feasible to use other materials. The main drawbacks are a less than ideal appearance and more tooth removal required for preparation. Environmental concerns about mercury usage is making this material less popular with the dental industry leading to its gradual replacement with newer materials. 

Inlay and Onlays

Sometimes, when a tooth is severely weakened for example after having a root treatment or when a wall of the tooth has fractured or when a cavity is   considered to be too extensive for restoring with a composite filling, a decision is made to place an inlay or an onlay in order to protect the structural integrity of the tooth. An inlay is contained within the tooth area while an onlay extends to replace one or more tooth cusps (pointed area of biting surface of tooth). Inlays and onlays are constructed from composite, porcelain or gold. They may be fabricated at the chair side (direct) or indirectly in a dental laboratory. 


Crowns are similar to onlays except that they enclose the entire tooth, covering all tooth surfaces like a cap. 

Crowns are used in a number of situations:

  • To protect a tooth that has been severely weakened as result of a large cavity
  • To protect a root-treated tooth from root fracture
  • To cover a dental implant
  • To cover a tooth, which is supporting a metal denture
  • To improve appearance as well as to strengthen a weakened tooth

Crowns are usually made indirectly. The dentist prepares the tooth and takes an impression or mold, which is then sent to a laboratory for the construction process. It is then returned for insertion and cementing on to the tooth by the dentist. The crown can be made from a variety of materials but is usually made from either gold on its own or a combination of gold or other precious material bonded to porcelain. 

A new type of manufacturing process developed in Switzerland called CEREC, using a whole range of computer assisted technologies to make ceramic restorations including inlays, onlays and crowns, has become very popular with dentists. These restorations can be constructed at the chair side in a single sitting. As the technology keeps improving, the CEREC crowns can match natural appearance and give good protection to restored teeth. This technology may also be used to construct high quality inlays, onlays and veneers from porcelain. 

Dental Insurance from the Dental Experts

All of our plans are based on our Healthy Smiles approach, which promotes regular and sustained preventive care by providing 100% cover for examinations, cleanings, and x-rays.

DeCare’s dental insurance plans for individual and corporate members offers up to 70% cover for fillings, crowns, inlays and onlays. View your policy to see what level of cover is on your plan.

To find out more, call 094 937 8608 or visit