One of the most important steps in endodontic therapy is obtaining an adequate access to the root canal system. This ensures adequate instrumentation, irrigation, visibility, access and disinfection, making endodontic therapy more predictable. However, in the process of gaining a good convenience form, access cavities are being excessively widened, weakening the tooth to masticatory forces and increasing their chance of fracture. Clark and Khademi introduced evidence based new concepts of modern endodontic access designs which primary aims at preservation of tooth structure and increasing fracture resistance of the tooth. Several techniques of modern access designs have been proposed but they all correspond to one fundamental concept, bio-minimalism. This review aims to comprehensively summarize the principles of modern access cavity preparation as well as highlight the various techniques of modern access cavity designs.