Accuracy of CBCT images in the assessment of buccal marginal alveolar peri-implant defects: Effect of field of view

Objectives: To investigate the reliability and accuracy of cone beam CT (CBCT) images obtained at different fields of view in detecting and quantifying simulated buccal marginal alveolar peri-implant defects. Methods: Simulated buccal defects were prepared in 69 implants inserted into cadaver mandibles. CBCT images at three different fields of view were acquired: 40×40, 60×60 and 100×100 mm. The presence or absence of defects was assessed on three sets of images using a five-point scale by three observers. Observers also measured the depth, width and volume of defects on CBCT images, which were compared with physical measurements. The kappa value was calculated to assess intra- and interobserver agreement. Six-way repeated analysis of variance was used to evaluate treatment effects on the diagnosis. Pairwise comparisons of median truepositive and true-negative rates were calculated by the x2 test. Pearson's correlation coefficient was used to determine the relationship between measurements. Significance level was set as p, 0.05. Results: All observers had excellent intra-observer agreement. Defect status (p <0.001) and defect size (p < 0.001) factors were statistically significant. Pairwise interactions were found between defect status and defect size (p50.001). No differences between median true-positive or true-negative values were found between CBCT field of views (p. >0.05). Significant correlations were found between physical and CBCT measurements (p < 0.001). Conclusions: All CBCT images performed similarly for the detection of simulated buccal marginal alveolar peri-implant defects. Depth, width and volume measurements of the defects from various CBCT images correlated highly with physical measurements. © 2014 The Authors. Published by the British Institute of Radiology.