About cavity design

Re-evaluation of the principles of cavity preparation, as proposed by G.V. Black

G.V. Black’s principles of cavity preparation were invented in order to prevent recurrent caries, at a time when the dental caries process was believed to be irreversible and adhesive restorative and fluoride releasing materials had not been developed. According to G.V. Black’s principles, tooth surfaces are divided into two groups:“self-cleansing” surfaces and “non self-cleansing” surfaces, where food debris and plaque can easily accumulate.
Therefore, in order to avoid recurrent caries, cavity “outline form” should include not only the caries lesion and the surrounding “non self-cleansing” areas, but also be extended into “self-cleansing” areas. This is the basic concept of “extension for prevention”, which has historically been followed since G.V. Black first proposed these principles over 70 years ago.
However, it is now currently clear that the caries process is a “dynamic” process, which alternates between periods of demineralization and remineralization. This has given rise to the notion that in certain instances the caries process is reversible and that some caries lesions can be “healed". In addition, we have seen great advances in adhesive dental technology. Under these circumstances, we must question whether it is correct to continue following G.V Black’s principles, that can result in the unnecessary removal of otherwise sound tooth structure?

Minimal intervention is basic to cavity preparation

We must try to discard the conventional cavity design with their vertical cavity walls, flat cavity floors and boxes, by remembering this results in the loss of sound tooth structures. Instead, we should apply the new MI concepts to cavity preparation.
This new principle aims to remove only the infected tooth structure during cavity preparation and preserves more sound tooth.
Consequently the final cavity design is very similar to the shape of the cavitated lesion.