Predictable endodontic therapy begins with good access preparation, which allows for the accurate location of any given orifice, facilitating the negotiating, securing, and shaping of the canal, as well as 3D disinfection and filling of the root canal system. Missed, unfilled, and untreated root canals have been identified as one of the leading causes of endodontic therapy failure in several investigations. With the advent of CBCT, magnification, ultrasonics and other diagnostic and treatment adjuvants, searching for and treating root canals has become easier and more predictable.