Minimal intervention: Early lesions

The use of modified cavity designs for the treatment of initial carious les ions can be justified on the grounds that, because no restorative material can adequately replace natural tooth structure for the long term, preservat ion of natural tooth structure is important. It is apparent that it is poss ible to remineralize and heal demineralized tooth structure to some degree. Therefore, neither enamel nor dentin should be removed simply because it h as lost calcium and phosphate ions as a result of acid attack. The older su rgical approach to cavity design was adopted in the absence of adhesive tec hniques and on the basis of Black's principle of "extension for prevention, " but this theory is no longer tenable. The current availability of adhesiv e bioactive restorative materials makes it possible to maintain areas of to oth structure even though they appear to be undermined and weakened. Thus, the concept of geometric designs for prescribed cavities is no longer valid . The purpose of this article is to describe a series of simplified, modifi ed cavity designs for small initial lesions; preservation of natural tooth structure is the principle objective of these designs.