Factors influencing optical 3D scanning of vinyl polysiloxane impression materials

Ralph DeLong, M R Pintado, Ching Chang Ko, James S Hodges, William H Douglas

Research output: Contribution to journalArticlepeer-review

38 Scopus citations


Purpose: Future growth in dental practice lies in digital imaging enhancing many chairside procedures and functions. This revolution requires the fast, accurate, and 3D digitizing of clinical records. One such clinical record is the chairside impression. This study investigated how surface angle and surface roughness affect the digitizing of vinyl polysiloxane impression materials. Materials and Methods: Seventeen vinyl polysiloxane impression materials were digitized with a white light optical digitizing system. Each sample was digitized at 3 different angles: 0°, 22.5°, and 45°, and 2 digitizer camera f-stops. The digitized images were rendered on a computer monitor using custom software developed under NIH/NIDCR grant DE12225. All the 3D images were rotated to the 0° position, cropped using Corel Photo-Paint 8 (Corel Corp, Ottawa, Ontario, Canada), then saved in the TIFF file format. The impression material area that was successfully digitized was calculated as a percentage of the total sample area, using Optimas 5.22 image processing software (Media Cybernetics, LP, Silver Spring, MD). The dependent variable was a Performance Value calculated for each material by averaging the percentage of area that digitized over the 3 angles. New samples with smooth and rough surfaces were made using the 7 impression materials with the largest Performance Values. These samples were tested as before, but with the additional angle of 60°. Silky-Rock die stone (Whip Mix Corp, Louisville, KY) was used as a control. Results: The Performance Values for the 17 impression materials ranged from 0% to 100%. The Performance Values for the 7 best materials were equivalent to the control at f/11 out to a surface angle of 45°; however, only Examix impression material (GC America Inc, Alsip, IL) was equivalent to the control at f/11∧16. At the 60° surface angle with f/11∧16, the Performance Values were 0% for all the impression materials, whereas that for the control was 90%. The difference in the Performance Values for the smooth and rough surface textures was 7%, which was not significant. Conclusions: The digitizing performance of vinyl polysiloxane impression materials is highly material and surface angle-dependent and is significantly lower than the die stone control when angles to 60° are included. It is affected to a lesser extent by surface texture.

Original languageEnglish (US)
Pages (from-to)78-85
Number of pages8
JournalJournal of Prosthodontics
Issue number2
StatePublished - Jun 2001

Bibliographical note

Funding Information:
From University of Minnesota School of Dentistry, Minneapolis, MN. 1Professor. 2Associate Professor. 3Assistant Professor. 4Sr Research Associate. 5Professor and Chair. Accepted March 2, 2001. Supported in part by NIH/NIDCR grants DE12225 and P30 DE09737 and the Minnesota Dental Research Center for Biomaterials and Biomechanics. Correspondence to: Ralph DeLong, DDS, MS, PhD, University of Minnesota School of Dentistry, 16-212 Moos Health Sciences Tower, 515 Delaware Street SE, Minneapolis, MN 55455. E-mail: delon002@umn.edu Copyright © 2001 by The American College of Prosthodontists 1059-941X/01/1002-0003$35.00/0 doi:10.1053/jpro.2001.24718


  • 3D scanning
  • Addition silicone
  • Dental die stone
  • Noncontact scanning
  • Optical scanning
  • Surface texture
  • Vinyl polysiloxane


Dive into the research topics of 'Factors influencing optical 3D scanning of vinyl polysiloxane impression materials'. Together they form a unique fingerprint.

Cite this