Introduction: Digital or optical impressions are becoming of increased use in prosthodontics, however, some studies reported that they were not able to trace mobile and smooth tissues of the edentulous arches. This study compared the optical impressions to the conventional impressions of the edentulous mandibular and maxillary arches via a digital superimposition process.
Materials and Methods: Optical impressions using the Omnicam, and conventional impressions using Zinc-Oxide eugenol material were made for 18 completely edentulous male patients. The master stone casts were scanned using the Kavo bench top scanner, and then a digital superimposition process of the master casts scans and the optical impressions was carried out using the Geomagic software, which presented the impressions deviations as surface color maps. Values of the deviations in the arches were calculated, and statistical analysis of the results was done using the Kruskal-Wallis test.
Results: In the maxillary arches, significant deviations of the optical impressions from the conventional impressions were found in the buccal vestibules, and in the mandibular arches, significant deviations were found in all the anatomical regions except for the residual ridges.
Conclusion
Optical impressions were not able to register the functional depth of sulcus in the maxillary and mandibular edentulous arches, neither the selectively pressed buccal shelves of bone and retromolar pads in the mandibular edentulous arches.