Abstract
Purpose: This in-vitro study aimed to compare the accuracy of complete arch scans (CAS) of a fully dentate (FD) and a partially edentulous (PE) maxillary model. Three intraoral scanning systems were used: Omnicam AC (OC), TRIOS 4 (TR), and Primescan (PS).
Methods: Each intraoral scanner was used to take 30 scans each of two clinical scenarios (FD and PE) simulated by a reference model. The PE model simulated a maxilla with six prepared teeth to accommodate a jaw-spanning fixed partial denture (FPD). The missing teeth were then added to create an FD model. Five ceramic precision balls (ball centers P1–P5) mounted on metal pins were welded to the metal base on the buccal side of the dental arch. These were later used to determine dimensional (given by each 2 ball centers) and angular changes (given by each 3 or 4 ball centers) between the reference model (digitized with high precision before the tests) and the intraoral scans. Data were statistically analyzed using a type II ANOVA.
Results: The maximum mean absolute distance deviations were as follows. OC: 147 µm (FD) and 139 µm (PE). TR: 133 µm (FD) and 136 µm (PE). PS: 87 µm (FD) and 80 µm (PE). The scanning system used had a significant effect on distance deviations (p < 0.027) and CAS scanning time (p < 0.001). Dental status had no clear effect on distance deviations but did significantly affect angular changes (p < 0.001) and scanning time (p < 0.001).
Conclusion: The manufacture of jaw-spanning FPDs based on a CAS cannot yet be recommended.
