A comparison of cone beam computed tomography and conventional periapical radiography at detecting peri-implant bone defects.

Objective: To compare the diagnostic accuracy of conventional periapical radiography and cone beam computed tomography (CBCT) at detecting peri-implant bone defects.

Materials And Methods: Implants were placed in fresh bovine ribs in osteotomy sites of varying diameter (five with no peri-implant space, five with a 0.35 mm space, five with a 0.675 mm space) and imaged using (i) digital long cone periapical radiographs (LCPAs), (ii) limited volume CBCT using 3D Accuitomo 80(®) and (iii) large volume CBCT using i-CAT Next Generation(®). Images from each were randomly presented to nine examiners on two occasions. Confidence in diagnosing the presence or absence of a peri-implant radiolucency was recorded on a five-point scale. Receiver Operating Characteristic (ROC) analysis and Kappa tests were performed.

Results: Digital LCPAs were better at diagnosing a peri-implant bone defect when the peri-implant space was 0.35 mm (P < 0.02). As the peri-implant space increased to 0.675 mm, there was no significant difference in diagnostic accuracy between the three imaging methods. Sensitivity of LCPAs (100) and Accuitomo (97.8) was better than i-CAT (64.4) (P < 0.02). LCPAs and i-CAT had significantly better specificity and positive predictive value than Accuitomo. The negative predictive value of LCPA was significantly better than i-CAT. LCPAs showed better intra-examiner and inter-examiner agreement than CBCT.

Conclusion: Within the limitations of this study, LCPAs are a reliable and valid method of detecting circumferential peri-implant bone defects and performed significantly better than CBCT.