Evaluation of marginal and internal gap of three-unit metal framework according to subtractive manufacturing and additive manufacturing of CAD/CAM systems.
- Author:
Dong Yeon KIM
1
;
Eo Bin KIM
;
Hae Young KIM
;
Ji Hwan KIM
;
Woong Chul KIM
Author Information
- Publication Type:Original Article
- Keywords: CAD/CAM; Micro-stereolithography; Metal framework; Marginal gap; Internal gap
- MeSH: Alloys; Bicuspid; Dental Prosthesis; Denture, Partial, Fixed; Molar; Replica Techniques; Silicon; Silicones
- From:The Journal of Advanced Prosthodontics 2017;9(6):463-469
- CountryRepublic of Korea
- Language:English
- 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.
