Divine, Katherine2018-11-282018-11-282018-08https://hdl.handle.net/11299/201014University of Minnesota M.S. thesis.August 2018. Major: Dentistry. Advisor: Scott McClanahan. 1 computer file (PDF); vii, 132 pages.Introduction: The morphology of the palatal root of maxillary first and second molars was analyzed and compared using micro-computed tomography (mCT) scanning. Methods: Forty-seven maxillary molars were scanned with a mCT device to analyze the palatal radicular dentin dimensions, canal working width, root length, canal curvature, lateral canals, and apical constriction anatomy. Quantitative data were analyzed with mean and standard deviation for first and second molars respectively. Comparison was made between first and second molars using an unpaired t-test. Results/Conclusions: The palatal root of maxillary first molars was found to have statistically significantly thinner dentin than second molars on the palatal aspect of the root 8-11mm from the apex, correlating to the coronal and middle thirds of root. First molar palatal roots also had a statistically significantly wider canal mesio-distally than second molars at 13-15mm from the apex, correlating approximately to the level of the CEJ and pulpal floor. Significant canal curvature was present. These findings suggest need for conservative coronal flaring and instrumentation. The absence of an apical constriction in 76.6% of specimens highlights the importance of creating an apical seat through instrumentation to maintain obturation materials. A minimum master apical file size of 40 is recommended based on pre-operative working widths in the apical 0.5-1.0mm. A root-end resection of 3.5mm would remove a greater majority of lateral canals.enanatomymaxillary molarmicro-computed tomographypalatal rootpostsurgeryThesis or Dissertation