J Adv Prosthodont.  2017 Dec;9(6):463-469. 10.4047/jap.2017.9.6.463.

Evaluation of marginal and internal gap of three-unit metal framework according to subtractive manufacturing and additive manufacturing of CAD/CAM systems

Affiliations
  • 1Department of Dental Laboratory Science and Engineering, College of Health Science, Korea University, Seoul, Republic of Korea. kuc2842@korea.ac.kr
  • 2Department of Public Health Sciences, Graduate School & BK21+ Program in Public Health Sciences, Korea University, Seoul, Republic of Korea.

Abstract

PURPOSE
To evaluate the fit of a three-unit metal framework of fixed dental prostheses made by subtractive and additive manufacturing.
MATERIALS AND METHODS
One master model of metal was fabricated. Twenty silicone impressions were made on the master die, working die of 10 poured with Type 4 stone, and working die of 10 made of scannable stone. Ten three-unit wax frameworks were fabricated by wax-up from Type IV working die. Stereolithography files of 10 three-unit frameworks were obtained using a model scanner and three-dimensional design software on a scannable working die. The three-unit wax framework was fabricated using subtractive manufacturing (SM) by applying the prepared stereolithography file, and the resin framework was fabricated by additive manufacturing (AM); both used metal alloy castings for metal frameworks. Marginal and internal gap were measured using silicone replica technique and digital microscope. Measurement data were analyzed by Kruskal-Wallis H test and Mann-Whitney U-test (α=.05).
RESULTS
The lowest and highest gaps between premolar and molar margins were in the SM group and the AM group, respectively. There was a statistically significant difference in the marginal gap among the 3 groups (P < .001). In the marginal area where pontic was present, the largest gap was 149.39 ± 42.30 µm in the AM group, and the lowest gap was 24.40 ± 11.92 µm in the SM group.
CONCLUSION
Three-unit metal frameworks made by subtractive manufacturing are clinically applicable. However, additive manufacturing requires more research to be applied clinically.

Keyword

CAD/CAM; Micro-stereolithography; Metal framework; Marginal gap; Internal gap

MeSH Terms

Alloys
Bicuspid
Dental Prosthesis
Denture, Partial, Fixed
Molar
Replica Techniques
Silicon
Silicones
Alloys
Silicon
Silicones
Full Text Links
  • JAP
Actions
Cited
CITED
export Copy
Close
Share
  • Twitter
  • Facebook
Similar articles
Copyright © 2022 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr