Accuracy and reliability of linear tooth and root length measurements derived from cone beam CT volumetric data

The purpose of this study was to test the accuracy and reliability of tooth and root length measurements derived from cone beam computed tomography (CBCT) volumetric data.;Replicate periapical radiographs (PARs) of 52 teeth were acquired on porcine heads. CBCT images were acquired of the heads using an i-CATRTM and oriented twice for each tooth. CBCT and PAR-based measurements were repeated for each CBCT orientation and PAR (i.e. each trial) using Dolphin 10.5RTM and ImageTool software, respectively. Actual lengths were measured from the extracted teeth.;CBCT measurements were not significantly different than the actual lengths. PAR measurements were less accurate, significantly underestimating true root lengths and overestimating tooth lengths.;Measurement reliability was lowest for PARs. Reliability between different trials was lowest for the 0.4 mm voxel size CBCT, which had reliabilities comparable to PARs. CBCT images were as accurate and reliable as PARs for tooth and root length determinations.