A new cavity classification.

With the development of adhesive restorative materials and a far better understanding of the action of the fluoride ion it is suggested that the time has arrived for a reassessment of the traditional cavity classification as set out by G.V. Black over one hundred years ago. When preventive measures and remineralization fail and a carious lesion has progressed through the enamel into the dentine there is a need to remove the infected dentine, and possibly some of the affected dentine as well, to eliminate cavitation and avoid further accumulation of plaque. In most situations this will involve removal of enamel to achieve access to the infected dentine but, in the presence of fluoride, both enamel and dentine are capable of being remineralized and therefore conserved, at least to a degree. The principle of minimal extension must be encouraged to allow maximum preservation of natural tooth structure. A new cavity classification is proposed which is designed to make the most of the potential for healing which is inherent in both enamel and dentine. However, it must be accepted that a considerable proportion of restorative dentistry is carried out to replace failed restorations and, in this case, cavity design will be complicated by existing loss of tooth structure.