TITLE: Estimating accuracy of the CBVT InVesalius Imaging Software to measure the volume of simulated periapical defects in a human cadaver mandible. AIM: This in vitro study tested the accuracy of CBVT InVesalius software to determine volumetric data as compared to true volume. METHODOLOGY: Ten artificial periapical osseous defects of similar size were created bilaterally in the posterior region of a human cadaver mandible. Vinyl polysiloxane impression material was injected to create a replica of each defect. The true volume of each replica was obtained using Archimedes' method and compared to volumetric measurements as determined by InVesalius. Statistical analysis was performed with one-way ANOVA and the significance level was set to p ≤ .05. RESULTS: The mean difference in volume measurement for InVesalius (.0454 cc) and Archimedes' method (.0436 cc) was very small (p = .48). CONCLUSION: InVesalius software appeared to accurately measure the true volume of the periapical defects.