Pilot Study Analysis of Four Types of Digitally Processed Models

Method: A die of Tooth #3 was fabricated using four methods (N=3 each group): conventional analog model (CAM) (Impression: Heraeus Flextime; Die: GC America, Fuji Rock); scanned impression material (SIM) (Impression: Heraeus Flextime; Die: inverted using MeshLab software); extracted die from scanned impression material (EXSIM) (Heraeus Flextime); intraoral digitally-processed model (IO) (MHT).  A typodont (Kilgore) was used as the master comparison model/control.  The master model and all models from each group were scanned using Smart Optics 880 to create a digital sample.  The scanner was calibrated according to manufacturer’s specifications before each use.  Using Exocad software, each digital sample was digitally matched to the master model digital sample at the highest and lowest points on each creating “superimposed test samples” (N=12).  All “superimposed test samples” were imported into Geomagic Qualify 2012 software and analyzed using 3D analysis to collect data about size/shape differences (in the overall models and specifically in each upper and lower arch) between the digitally-processed models and the conventional model.  Average maximum deviation and average minimum deviation were analyzed using Geomagic.

Result:

Conclusion:  3D analysis of all “superimposed test samples” resulted in comparable results.  Further testing is necessary to determine if this method of evaluation is effective in testing accuracy of digitally-processed models.