Clinical studies demonstrate that long term prognosis of the root filled teeth is influenced by the quality of the restoration as well as by the quality of the root canal treatment itself. The most recent trends in restoration of endodontically treated teeth are following the concept of minimally invasive dentistry, based mostly on adhesive dentistry and new materials and technologies. Following these trends, the access procedures in endodontics and the root canal preparation are changing in a conservative way, sometimes drastically if compared with the traditional concepts of cavity outline opening and coronal straight-line access to reach the apical region. Endodontic literature appears to be poor on demonstrating how these minimal invasive access procedures can influence the quality and prognosis of root canal treatment. The present lecture will analyze the technical procedures of minimal invasive access in different clinical situations and the possible mechanical improvements derived from it. Moreover the limits of these procedures will be critically analyzed to define how much minimal invasive clinicians should be in order to ensure gold standard endodontic treatments.