Clinical evaluation comparing the fit of all-ceramic crowns obtained from silicone and digital intraoral impressions

Clin Oral Investig. 2016 May;20(4):799-806. doi: 10.1007/s00784-015-1590-5. Epub 2015 Sep 12.

Abstract

Objectives: The aim of this study is to compare the fit of all-ceramic crowns fabricated from conventional silicone impressions with the fit of all-ceramic crowns fabricated from intraoral digital impressions.

Methods: Twenty patients with 26 posterior teeth with a prosthetic demand were selected for the study. Two crowns (Straumann-Zerion) were made for each preparation. One crown was fabricated from an intraoral digital impression system (IDI group; Cadent-iTero), and the other crown was fabricated from a conventional one-step silicone impression (CI group; Express Penta Putty and Body Light). To replicate the interface between the crown and the preparation, each crown was cemented on its corresponding clinical preparation with ultra-flow silicone (Express Ultra Light Body). Each crown was embedded in resin to stabilize the registered interface, cut in 2-mm-thick slices in a buco-lingual orientation. Internal misfit was measured in microns using stereomicroscopy with a magnification of ×40. Measurements were taken at different landmarks: margin, chamfer angle, axial, crest, and occlusal fosse. After checking for normality, data was analyzed using paired Student's t test (α = 0.05).

Results: Fit values were significantly affected by the impression technique (p = 0.000). Mean internal misfit and mean marginal misfit were 111.40 μm (SD = 54.04)/80.29 μm (SD = 26.24) for the crowns of the IDI group and 173.00 μm (SD = 92.65)/133.51 μm (SD = 48.78) for the CI group.

Conclusion: All-ceramic crowns fabricated from intraoral digital impressions with parallel confocal technology demonstrated a clinically acceptable internal and marginal fit as conventional impression.

Clinical significance: Intraoral digital impressions as initial step to the digital workflow could further improve the marginal adaptation of all ceramic single crowns.

Trial registration: http://www.isrctn.com/ISRCTN16111844.

Keywords: All-ceramic crowns; CAD/CAM; Dental impression materials: silicone; Digital impression; Intraoral scanner; Marginal fit; Replica technique.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Computer-Aided Design
  • Crowns*
  • Dental Impression Materials
  • Dental Impression Technique*
  • Dental Marginal Adaptation
  • Dental Porcelain
  • Dental Prosthesis Design*
  • Humans
  • Silicones
  • Surface Properties

Substances

  • Dental Impression Materials
  • Silicones
  • Dental Porcelain

Associated data

  • ISRCTN/ISRCTN16111844