Digital impression accuracy for bone-level and tissue-level implants using scan bodies of different heights

Intraoral scanning has gained acceptance for its accuracy comparable to conventional implant impressions. This study compared digital impression accuracy based on implant placement level and scan body height. Two mandibular partial edentulous models missing the left second premolar and first molar, were used: one with a tissue level implant and the other with a bone level implant. Models were divided into four groups: Group TS-S (bone level, short scan bodies), Group TS-R (bone level, Regular scan bodies), Group SS-S (tissue level, short scan bodies), and Group SS-R (tissue level, Regular scan bodies). Each group was scanned with a model scanner for reference STL files and two intraoral scanners (IOSs; Medit i700, Cerec Primescan) for experimental STL files. Deviation between experimental and reference STL files was measured. The Medit i700 demonstrated smaller scan discrepancies compared to the CEREC Primescan. For both intraoral scanners, the use of short scan bodies resulted in higher trueness than regular scan bodies. Tissue level implants exhibited greater trueness and precision than bone level implants (p < 0.05). These findings indicate that both the implant placement level and scan body height are factors that can influence the accuracy of digital impressions.