Abstract
Purpose: Within the specialty of prosthodontics, oral impressions are ubiquitous tools utilized to transfer
intraoral characteristics such as teeth, implants, and soft tissue into a physical state (stone cast) that
is processable in a laboratory setting for the fabrication of dental restorations. In recent years, optical
impression systems have become ubiquitous in clinical practice replacing the conventional method of
impression making. The purpose of the present study was to evaluate the feasibility and accuracy of
computerized optical impression making of edentulous jaws in an in vivo setting.
Methods: 29 edentulous patients (27 maxillae and five mandibles) underwent conventional impressions
as well as computerized optical impressions. The conventional impressions and the resulting stone casts
were digitized and superimposed over the computerized/digitized optical impressions in order to obtain
information on differences between the two datasets. Statistical analyses were performed to identify rel-
evant deviations.
Results: The overall mean difference between the stone cast, digital scans and the computerized optical
scans were 336.7 ± 105.0 μm ( n = 32), 363.7 ± 143.1 μm ( n = 24), and 272.1 ± 168.5 μm ( n = 29),
respectively. The visual evaluations revealed highest deviations ( ≥ 500 μm) in the areas of the soft palate,
the sublingual areas, and the vestibule (peripheral seal zone).
Conclusions: Within the limitations of the present study, the investigated scanners were not able cur-
rently to fully replace a conventional impression for the fabrication of a complete denture.
