Rationale for designing cavity preparations.

Increased resistance to caries, increased dental awareness, superior diagnostic capabilities, better illumination, optical aids that significantly enhance vision, improved and standardized materials for restoration, and a deeper understanding of the caries process enable a far more conservative approach to tooth preparation. The dentist can concentrate on preserving as much sound tooth structure as possible with less attention being devoted to resistance and retention form that previously demanded in bulk restorations and massive channels and locks that are no longer appropriate. Although caries inhibitory effects have been shown with materials such as silicate cement, glass ionomers, and resins that leach fluoride, in general, dentists should not rely on restorative materials to inhibit the development of future decay.

Rationale for designing cavity preparations in light of current knowledge and technology.

No restorative material presently available is as good as supported tooth structure and it is unlikely that a usable dental restorative material with the physical properties of enamel will ever be developed. The purpose of cavity preparation is to remove carious material and preserve sound tooth structure. Any additional removal of tooth structure is necessary for the convenience of the operator or because of limitations of the restorative materials.