Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: During root canal treatment (RCT), an opening is made through the crown of the tooth to access and to disinfect the root canal system (RCS). Traditional endodontic access (TEA) may sacrifice tooth structure and weaken the tooth. Cone beam computed tomography (CBCT) provides information about the exact location of the root canals. This information can be used for the design of a canal-directed endodontic access (CDEA). It may also be used for the 3D printing of an acrylic endodontic stent that could help to create a conservative CDEA. Objective: 1) Evaluate the ability of the Dolphin 3D imaging software to assist in creating a CDEA; 2) Compare tooth structure loss in a CDEA to that in a TEA by measuring the volume of remaining tooth structure, surface area of the access opening at the occlusal, and remaining dentin thickness at the CEJ. Materials and Methods: Thirty extracted human mandibular premolars were used. Teeth with large, wide canals were excluded. CBCT images will be taken for all teeth using Kodak 9000. Fifteen teeth were randomly assigned to the TEA group and 15 teeth were assigned to the CDEA group. The CDEA path was mapped using Dolphin 3D imaging software. Acrylic access stents were designed using Rhino 3D software and printed using a 3D printer. The teeth were accessed through the corresponding stents. The 15 teeth that are part of the traditional access group were accessed without a stent. A CBCT scan was taken post-access for all 30 teeth. Wilcoxon Rank Sum Tests were performed to compare the following outcomes for the two groups: the volume of remaining tooth structure, the surface area of the access opening at the occlusal, and remaining dentin thickness at the CEJ. Results: The remaining dentin thickness (percent loss) was not significantly larger for TEA than for CDEA. The surface area (post-treatment) was significantly larger for TEA than for CDEA, and volume (percent loss) was significantly larger for TEA than for CDEA. Conclusion: The use of the CBCT and Dolphin 3D imaging provided an accurate and more conservative CDEA with the guide of an acrylic stent.