The accuracy of periapical radiography and cone beam computed tomography in measuring periodontal ligament space: Ex vivo comparative micro‐CT study

Abstract Our aim was to measure PDL space width using periapical radiography, CBCT and micro‐CT. Dry human mandibular bones ( n = 36) consisting of 59 molar and 36 premolar teeth were used. Four image sets were obtained as follows: (i) photostimulable phosphor plate (PSP), periapical radiography, (ii) CBCT 0.075 mm voxel size, (iii) CBCT 0.2 mm voxel size and (iv) micro‐CT 0.06 mm voxel size. Micro‐CT images were considered as the gold standard. Four observers measured the PDL space widths twice. Intra‐ and interclass correlation coefficients (ICC) were calculated. Spearman’s rho correlation was assessed. PDL space widths ranged between 0.16 and 0.28 mm. There was good reliability within and between observers ( P < 0.01). There was no significant relationship between micro‐CT and periapical imaging. ( P > 0.05). Best observer performance was obtained from CBCT 0.075 mm voxel size images followed by CBCT 0.2 mm voxel size images.