This network meta-analysis (NMA) aimed to compare the complete-arch scanning accuracy
of different intraoral scanners (IOSs) to that of reference standard tessellation
language (STL) files.Studies comparing the trueness and precision of IOS STL files
with those of reference STL scans for different arch types (dentate, edentulous, completely
edentulous with implants, and partially edentulous with implants) were included in
this study.An electronic search of five databases restricted to the English Language
was conducted in October 2021.A total of 3,815 studies were identified, of which 114
were eligible for inclusion. After study selection and data extraction, pair-wise
comparison and NMA were performed to define the accuracy of scanning for four arch
subgroups using four outcomes (trueness and precision expressed as mean absolute deviation
and root mean square values). Cochrane guidelines and the QUADAS-2 tool were used
to assess the risk of bias. GRADE was used for certainty assessment.Fifty-three articles
were included in this NMA. Altogether, 26 IOSs were compared directly and indirectly
in 10 network systems. The accuracy of IOSs scans were not significantly different
from the reference scans for dentate arches (three IOSs), edentulous arches (three
IOSs), and completely edentulous arches with implants (one IOS). The accuracy of the
IOSs was significantly different from the reference scans for partially edentulous
arches with implants. Significant accuracy differences were found between the IOSs,
regardless of clinical scenarios.The accuracy of complete-arch scanning by IOSs differs
based on clinical scenarios.Different IOSs should be used according to the complete
arch type.
