Accuracy of Cone Beam Computed Tomography Over Conventional Radiography (IOPA), Clinical Probing and Direct Surgical Measurements in the Assessment of Periodontal Defects

Introduction: Currently the main diagnostic tools for periodontal diseases are clinical probing and intraoral radiography. However, both techniques have its own limitation in assessment of periodontal bone loss. Periodontal diagnosis relies heavily on traditional two dimensional radiographic assessments. Lack of three dimensional information of the dentition was overcome by the introduction of CT scan, however the increased radiation exposure and high cost was its main disadvantage. Recently, Cone Beam Computed Tomography (CBCT) has turned this concept into potential reality because these lower-cost small machines produce high-quality data. Yet there is little research to establish periodontal bone measurement using CBCT as a valid method. Aim: To compare linear measurements of periodontal defects using CBCT to clinical, Intraoral radiographs and open bone measurements. Materials and Methods: This study was conducted in the Department of Periodontology in association with the Department of Oral Medicine and Radiology, Yenepoya Dental College, Yenepoya University, Mangaluru. Sixty-three periodontal bone defects in patients suffering from periodontitis and scheduled for flap surgery were included in the study. Based on clinical and radiographic assessment, the periodontal defects were grouped into three groups. Group A- Horizontal bone loss (21 sites), Group B -Vertical bone loss (21 sites) and Group C- Furcation defects (21 sites). On the day of surgery prior to anaesthesia, after obtaining clinical probing measurements, CBCT and IOPA (Long cone paralleling technique with grid) of the quadrant to be operated was taken. After reflection of the flap, direct measurements were obtained for all the periodontal defects. The measurements taken during surgery were then compared to the measurements done with CBCT, IOPA and clinical probing subjected to statistical analysis using the Intra class correlation coefficient and Paired t-test. Results: Overall there was a very high correlation between the direct bone and CBCT measurements. For horizontal bone defects, Intra-class correlation coefficient showed excellent agreement of CBCT measurements with direct bone measurements in all the areas around the tooth where as IOPA and clinical probing showed moderate agreement. No significant difference was obtained between CBCT and direct bone measurements in the mesiobuccal, mesiolingual/mesiopalatal and distobuccal areas. For vertical bone loss, no significant difference wa