Volumetric Analysis of Post Space Impressions Made using Digital Scan and Cone Beam Computed Tomography Imaging: An In-vitro Study

Introduction: Digital impressions are dental scans captured using Three-dimensional (3-D) scanning technology. Scanning deeper areas can affect the accuracy and completeness of the digital impression, potentially leading to inaccuracies in the final restoration. Scanning post spaces at greater depths and narrower diameters can pose significant challenges for digital scanning. Aim: To compare the volume of post space impressions made using the digital impression technique (Primescan/Dentsply Sirona) with the volume obtained from Cone Beam Computed Tomography (CBCT) imaging. Materials and Methods: The present in-vitro study was conducted between January and April 2025 in the Department of Conservative Dentistry and Endodontics at DAPM RV Dental College, Bengaluru, Karnataka, India. A total of 15 extracted single-canal, single-rooted permanent teeth were collected for this in-vitro study. All the teeth were cut coronally to maintain an equal length of 22 mm. Endodontic treatment was performed on all the teeth, followed by post space preparation, leaving behind 5 mm of gutta-percha. Group A: A CBCT reference scan was performed for all the samples; the volume of the post space was measured using on-demand software for each tooth, which served as a control. Group B: The same samples were subjected to a digital impression (Primescan/Dentsply Sirona), and the volume of the post space was recorded using Exocad software. Group B values were compared with the corresponding group A reference values. Results: The intraoral scanned images (group B) recorded a slightly smaller volume than that obtained from CBCT. Although the mean difference between the two methods was 0.7384 mm3 , it was shown to be statistically significant (p<0.001). Conclusion: Based on the analysis of the study results, it can be concluded that the mean difference in volume between CBCT and Primescan was 0.738 mm3 , with the Primescan recording 97.82% of the volume. The Primescan demonstrates clinically acceptable accuracy in scanning the post space.