A tooth substance saving restorative technique.

The basic concept behind the Black system in the restoration of teeth is a mechanical one. It aims at the retention of restorations by perfect contact with, and the grip of, resilient sound dentinal cavity walls. This necessitates the cutting of sound dentin which is sometimes accompanied by pain and pulpal irritation. For the complete removal of infected carious dentin the conventional technique has depended upon the operator's perception of discoloured dentin and its changed hardness. It has been shown that carious dentin consists of two layers. Namely, a superficial layer which is infected, not remineralizable and necrotic, whereas the deeper layer is uninfected, remineralizable and vital. The first step in the tooth substance saving restorative technique is to use a dye to differentiate between the two layers. Pain on caries removal is virtually eliminated by the selective removal of the stained and necrotic superficial layer while assuring complete removal of all infected dentin. The second step is to use chemically adhesive composite resins which have been developed for both anterior and posterior use. They adhere to enamel and sound dentin and also to the deeper layer of carious dentin. Cutting painful tissue so as to provide the retention form of the classical technique is not required, nor is amalgam as a restorative material in operative dentistry.