[Accuracy of cone beam computed tomography, intraoral radiography and periodontal probing for periodontal bone defects measurement]

Cone beam computed tomography [CBCT] produces high-quality data about diagnosis and periodontal treatment. To date, there is not enough research regarding periodontal bone measurement using CBCT. The aim of this study was to compare the accuracy of CBCT in measuring periodontal defects to that of intraoral radiography and probing methods. Two-hundred and eighteen artificial osseous defects [buccal and lingual infrabony, interproximal, horizontal, crater, dehiscence and fenestration defects] were created on 13 mandibles of dry skulls. The mandibles were put into a plexiglass box full of water to simulate soft tissue. CBCT images, radiographic images taken with parallel technique and direct measurements using a WHO periodontal probe were recorded and compared to a standard reference [digital caliper]. Inter and intra observe consistencies were assessed using Intra class correlation coefficient and pearson correlation. Inter and intra observer consistencies were high for CBCT and probing methods [ICC-Intra class correlation coefficient>88%], but moderate for intraoral radiography [ICC-Intra class correlation coefficient>54%]. There were not any significant differences between observers for all techniques [P>0/05]. According to paired T-test analysis, mean difference for CBCT technique [0.01 mm] was lower than that for probing [0.04 mm] and radiography [0.62 mm]. CBCT was able to measure all kinds of lesions, but radiography could not measure defects in the buccal and lingual sites. All three modalities are useful for identifying periodontal defects. Compared to probing and radiography, the CBCT technique has the most accuracy in measuring periodontal defects