Aim: the main difficulties for intraoral scanners (IOS) are found in
the edentulous mandibles. The reduced bucco-lingual surface, the
limited height of the bone crest and the mobility of the soft tissues
generate criticalities for the acquisition of the digital impression.
The purpose of this study is to evaluate the comparison between
digital and analog impressions in these particular conditions.
Methods: two scans were obtained for the 11 subjects. The first
intraoral scan was carried out with intraoral scan (Omnicam
DentsplySirona) and the second was acquired by digitizing a plaster
model, obtained from an impression taken with an analogue
method, the best choice in these cases. All scans were converted
to standard tessellation language (STL). The STL files obtained for
each patient were superimposed by means of the GEOMAGIC
Control X software, to evaluate the comparison.
The average distance values obtained through the Geomagic
3D software constitute our primary outcome measure. 1 sample
t-test was used to prove the hypothesis that the average
distances of the points obtained between the two files are relevant
(α = .05).
Results: concerning the scans ability to reproduce the analog
impression the intraoral scans carried out with a intraoral scan
generated files with single measurements in terms of minimal
distance between objects far from scans obtained with analogue
methods (t =-7.29, P < .001).
Conclusion: regarding the results obtained, it was possible to
conclude that the STL files deriving from digital impressions
are significantly different from those deriving from analog impressions,
highlighting a difference between the two methods
