Abstract: Objective To in vivo evaluate the accuracy of 3Shape TRIOS for the whole maxilla. Methods 28 healthy volunteers were recruited in the study. Everyone’s whole maxilla got intraoral scan for three times by 3Shape TRIOS and then received one conventional silicon impression. The conventional impression was poured into a gypsum castand three-dimensional(3D) digitized image was captured from the cast by an extraoral scanner, as the reference model. All datasets were imported to Geomagic software for 3D analysis. Color-coded deviation maps showed qualitative visualization of the deviations. Results For the digital impressions of palatal soft tissues, the accuracy was (131.70±35.50)μm and precision was (54.51±10.87)μm. For the digital impressions for upper full dentitions,accuracy was (77.95±13.86)μm and precision was (58.88±11.51)μm. There was no significant effect of palatal vault height on accuracy of digital impressions of palatal soft tissues (P>0.05), but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (P=0.02). Conclusions It is feasible to use the intraoral scanner to obtain digital impressions for whole upper jaws. Further studies should be carried out to confirm whether the accuracy of digital impressions for whole upper jaws is acceptable in clinic.

Key words: intraoral digital impression, palatal soft tissues, full dentition, accuracy