Master of Science, The Ohio State University, 2018, Dentistry

Statement of problem. While the accuracy of digital implant impressions in single unit and short span situations has been demonstrated, the effect of various scan bodies and scan techniques on the accuracy and scan time in completely edentulous situations is not well understood. Purpose. The purpose of this study was to evaluate the effects of 4 different scanning techniques and 5 different commercially available intraoral scan bodies on the trueness (distance and angular deviation), precision (variance amongst the scans) and scan time in a completely edentulous situation with 4 implants. Materials and Methods. Five different intraoral scan body systems were evaluated: AF ( IO-Flo, Atlantis Denstply Implants), NT (Nt-Trading GmbH & Co. KG), DE (Dess-USA), C3D (Core3Dcentres NA), and ZI (Zimmer Biomet Dental), and 4 different scanning techniques were evaluated: unmodified master model (NO), glass fiduciary markers placed on the edentulous ridge (GB), pressure indicating paste brushed over the ridge and palate (PP), and floss tied between the scan bodies (FL). Five identical polyurethane edentulous maxillary models with 4 parallel dental implant analogs (TSV 4.1, Zimmer Biomet Dental) in the first molar and canine positions. The scan bodies were attached to the models and the entire surface was scanned using a calibrated structured blue light industrial scanner (Carl Zeiss Optotechnik GmbH) to generate a master reference model. Five consecutive digital impressions were made of the model using an intraoral scanner (Trios, 3Shape A/S) and 1 of the 4 techniques (n=5) assigned at random. The test scans were superimposed over the master reference model using a best fit algorithm, and then the distance deviation and angular deviation of the scan bodies was calculated. Scan time was also recorded. A two-factor ANOVA was used to examine the effect of scan body and technique on the trueness and on scan time, with subsequent Tukey or Bonferroni-corrected Student's t-tes (open full item for complete abstract)

Committee: Burak Yilmaz DDS, PhD (Advisor); Edwin McGlumphy DDS, MS (Committee Member); Jeremy Seidt PhD (Committee Member); William Johnston MS, PhD (Committee Member) Subjects: Dentistry