Accuracy Assessment of a Novel Radiographic Method to Evaluate Guided Bone Regeneration Outcomes Using a 3D-Printed Model

The aim of this study was to evaluate the accuracy and reproducibility of a morphological contour interpolation (MCI) based segmentation method for the volumetric measurement of bone grafts around implants. Three 3D-printed models (one with a cylinder and two with a geometrically-complex form) were fabricated to simulate implant placement with a simultaneous guided bone regeneration (GBR) procedure. All models were scanned using a cone beam computed tomography (CBCT) instrument with the same parameters. The true volumes of the bone grafts in the models were assessed using computer-aided calculation (controls). For the test measurements, both manual and MCI-based methods were used. A comparison between the measured and true volumes was performed to evaluate the accuracy. The coefficients of variation of repeated measurements were calculated to evaluate the reproducibility. In addition, the execution time was recorded and a comparison between the two methods was performed. The high accuracy of the MCI-based method was found with differences between the measured value and actual volume, which never exceeded 7.3%. Excellent reproducibility was shown, with coefficients of variation never exceeding 1.1%. A shorter execution time was observed for the MCI-based method than for the manual method. Within the confines of this study, the MCI-based method may be suitable for volumetric measurements of grafted bone around implants. © 2021, Shanghai Jiao Tong University and Springer-Verlag GmbH Germany, part of Springer Nature.