Accuracy of Post-Endodontic Digital Impression With Intraoral Scanner Versus Conventional Impression

Objectives: The development of CAD/CAM technology introduced a novel manufacturing approach for anatomical posts, ensuring improved fit and a minimal layer of cementation resin. The study aimed to evaluate the precision of the post-space reading, using an intraoral scanner (IOS), compared to a conventional impression technique.
Methods: Fifteen acrylic typodont teeth with root canals, representing three types (11,14,17) were decoronated 1 mm coronal to the most incisal point of the cement–enamel junction. One root per tooth was endodontic treated and enlarged to a tapered shape (3 mm coronal diameter, length 9 mm). All teeth were embedded in acrylic resin. For the study group they were scanned using an intraoral dental scanner (Trios 4). For the control group, conventional impressions of each tooth were obtained using elastomer based on a-silicone and digitized with an optical scanner. The combined impressions were transformed into a virtual 3D model using a software “Geomagic”. Subsequently, accuracy was assessed through data analysis by use of the platform “Matlab”.
Results: At the depth of 1 mm in the coronal region of the root, the disparity between the two groups was about 0.03 mm. However, as the depth increased to 5 mm, the difference became more pronounced. Beyond this depth, significant outliers were observed, with values exceeding +/- 0.5 mm. This suggests that the digital impression struggles to accurately capture the intricacies of the post-space.
Conclusions: This in vitro study reveals that employing an IOS to assess post-space anatomy lacks reliability, primarily due to limitations in depth readings. The study’s results highlight a significant decline in scanning accuracy beyond a depth of 5 mm, suggesting that the IOS struggles to effectively capture data from the deeper regions of the post-space, resulting in incomplete readings.