Volumetric analysis of simulated bone defects: a comparative study using cone beam computed tomography and intraoral scanners

This in vitro study aimed to evaluate and compare the accuracy and reliability of cone-beam computed tomography (CBCT) and intraoral scanner (IOS) in measuring the volume of simulated bone defects. Additionally, it aimed to assess how the number of missing cortical bony walls in a bone defect affects the accuracy of volumetric measurements. Bovine rib blocks were used to create 42 simulated bone defects, which were then divided equally into two groups. One cortical plate was perforated in Group I, whereas both the buccal and lingual cortical plates were perforated in Group II. Defect volumes were assessed using CBCT and IOS. Every measurement was compared to a gold standard derived using Archimedes' principle. Volumetric analysis revealed that the IOS measurements in both groups showed no statistically significant difference when compared to the gold standard. CBCT measurements in Group I also showed no significant difference from the gold standard. However, in Group II, CBCT volumetric measurements differed significantly from the gold standard (p = 0.001). Both CBCT and IOS demonstrated accuracy in measuring bone defects when only one cortical wall was perforated. However, when both cortical plates were lost, IOS showed superior accuracy compared to CBCT segmentation. IOS measurements had no significant deviation from the gold standard volume (P = 0.88), while CBCT measurements exhibited a significant deviation (P = 0.001). Therefore, IOS presents a reliable, radiation-free alternative for monitoring volumetric bone defects across different degrees of cortical bone loss.