Concept of minimal intervention dentistry has evolved as a consequence of increased understanding of the carious process and the development of adhesive restorative materials. It is now recognized that demineralized but non cavitated enamel and dentin can be healed and that surgical approach to the treatment of a carious lesion along with “EXTENSION FOR PREVENTION” as proposed by G.V. Black is no longer tenable. Term minimal intervention is relatively new in dentistry and has been introduced to suggest to the profession that it is time for changes in the principles of operative dentistry. The ultimate goal of minimal intervention is to extend the life of restored teeth with as less intervention as possible. When operative care is indicated, it should be aimed at “PREVENTION OF EXTENSION” rather than “EXTENSION FOR PREVENTION”.