EXPERIMENTAL EVALUATION OF INTRAORAL SCANNERS IN EDENTULOUS MANDIBLES

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.