TY - JOUR
T1 - Comparison and evaluation of marginal and internal gaps in cobalt–chromium alloy copings fabricated using subtractive and additive manufacturing
AU - Kim, Dong Yeon
AU - Kim, Ji Hwan
AU - Kim, Hae Young
AU - Kim, Woong Chul
N1 - Funding Information:
This study was supported by a Korean University Grant . This study was supported by the Ministry of Trade, Industry & Energy ( 20133110002881 ). The study was supported by SM (smile maker) dental laboratory .
Publisher Copyright:
© 2017 Japan Prosthodontic Society
PY - 2018/1
Y1 - 2018/1
N2 - Purpose To evaluate the marginal and internal gaps of cobalt–chromium (Co–Cr) alloy copings fabricated using subtractive and additive manufacturing. Methods A study model of an abutment tooth 46 was prepared by a 2-step silicone impression with dental stone. Fifteen stereolithography files for Co–Cr alloy copings were compiled using a model scanner and dental CAD software. Using the lost wax (LW), wax block (WB), soft metal block (SMB), microstereolithography (μ-SLA), and selected laser melting (SLM) techniques, 15 Co–Cr alloy copings were fabricated per group. The marginal and internal gaps of these Co–Cr alloy copings were measured using a digital microscope (160×), and the data obtained were analyzed using the non-parametric Kruskal–Wallis H-test and post-hoc Mann–Whitney U-test with Bonferroni correction. Results The mean values of the marginal, axial wall, and occlusal gaps were 91.8, 83.4, and 163 μm in the LW group; 94.2, 77.5, and 122 μm in the WB group; 60.0, 79.4, and 90.8 μm in the SMB group; 154, 72.4, and 258 μm in the μ-SLA group; and 239, 73.6, and 384 μm in the SLM group, respectively. The differences in the marginal and occlusal gaps between the 5 groups were statistically significant (P <.05). Conclusions The marginal gaps of the LW, WB, and SMB groups were within the clinically acceptable limit, but further improvements in the μ-SLA and SLM approaches may be required prior to clinical implementation.
AB - Purpose To evaluate the marginal and internal gaps of cobalt–chromium (Co–Cr) alloy copings fabricated using subtractive and additive manufacturing. Methods A study model of an abutment tooth 46 was prepared by a 2-step silicone impression with dental stone. Fifteen stereolithography files for Co–Cr alloy copings were compiled using a model scanner and dental CAD software. Using the lost wax (LW), wax block (WB), soft metal block (SMB), microstereolithography (μ-SLA), and selected laser melting (SLM) techniques, 15 Co–Cr alloy copings were fabricated per group. The marginal and internal gaps of these Co–Cr alloy copings were measured using a digital microscope (160×), and the data obtained were analyzed using the non-parametric Kruskal–Wallis H-test and post-hoc Mann–Whitney U-test with Bonferroni correction. Results The mean values of the marginal, axial wall, and occlusal gaps were 91.8, 83.4, and 163 μm in the LW group; 94.2, 77.5, and 122 μm in the WB group; 60.0, 79.4, and 90.8 μm in the SMB group; 154, 72.4, and 258 μm in the μ-SLA group; and 239, 73.6, and 384 μm in the SLM group, respectively. The differences in the marginal and occlusal gaps between the 5 groups were statistically significant (P <.05). Conclusions The marginal gaps of the LW, WB, and SMB groups were within the clinically acceptable limit, but further improvements in the μ-SLA and SLM approaches may be required prior to clinical implementation.
KW - Additive manufacturing
KW - CAD/CAM
KW - Cobalt–chromium
KW - Internal gap
KW - Marginal gap
UR - http://www.scopus.com/inward/record.url?scp=85021753461&partnerID=8YFLogxK
U2 - 10.1016/j.jpor.2017.05.008
DO - 10.1016/j.jpor.2017.05.008
M3 - Article
C2 - 28663024
AN - SCOPUS:85021753461
VL - 62
SP - 56
EP - 64
JO - Nippon Hotetsu Shika Gakkai zasshi
JF - Nippon Hotetsu Shika Gakkai zasshi
SN - 1883-1958
IS - 1
ER -