Comparisons of precision and trueness of digital dental casts produced by desktop scanners and intraoral scanners

Background/purpose: Different types of scanners are gradually used to produce digital dental casts in the current dental practice. This study tested the accuracy of the three desktop scanners and two intraoral scanners and evaluated whether the desktop scanners had higher precision than the intraoral scanners. Materials and methods: This study used the three desktop and two intraoral scanners to scan a standard dental cast 5 times. The 5 digital casts produced by the same scanner were compared each other to study the precision errors of each scanner. Moreover, 5 sets of the 5 digital casts produced by the 5 different scanners were compared each other to investigate the trueness errors among these 5 different scanners. Results: This study showed a significant difference in the precision error of produced digital casts made by the 5 different scanners (P < 0.0001). The two intraoral scanners had significantly higher precision errors of produced digital casts than the three desktop scanners. However, there were no significant differences in the precision errors among the three desktop scanners and between the two intraoral scanners. The results of the whole cast or particular tooth surface trueness analyses demonstrated that the trueness errors were concentrated at the molar regions of produced digital casts when comparisons were performed between the intraoral and desktop scanners. Conclusion: We conclude that the desktop scanners can achieve a better precision than the intraoral scanners. When the intraoral scanner is used, the dentist should notice the possible model errors at the molar regions.