Suitability of Magnetic Resonance Imaging for Guided Endodontics: Proof of Principle.

Introduction This proof-of-principle study aimed to demonstrate that magnetic resonance imaging (MRI) is sufficiently accurate for the detection of root canals using guided endodontics. Methods One hundred extracted human teeth (anterior and premolar) were mounted onto five mandibular and five maxillary models, fitted with splints designed to accommodate a thin layer of aqueous gel for indirect imaging, and scanned by MRI. After MRI and intra-oral scans were aligned using planning software, access cavities were planned virtually, and templates were CAD/CAM manufactured, access cavities were prepared. Cone-beam computed tomography (CBCT) scans were performed and matched with the virtual preoperative planning data to determine the accuracy of access cavity preparation in terms of deviation between planned and prepared cavities in mesiodistal and buccolingual dimension and angle. Descriptive statistical analysis was performed and mean values were compared by t-test. Results Ninety-one of 100 root canals were successfully scouted after MRI-guided access cavity preparation. Mean angle deviation was 1.82 degrees. Mean deviation ranged from 0.21mm to 0.31mm at the base of the bur, and from 0.28mm to 0.44mm at the tip of the bur. Preparation in buccolingual dimension was significantly more precise in mandibular compared to maxillary teeth, and accuracy in mesiodistal dimension was more precise in anterior teeth compared to premolars. Conclusion This in-vitro study demonstrated the suitability of MRI for guided endodontic access cavity preparation.