PMID- 32893016
OWN - NLM
STAT- MEDLINE
DCOM- 20210809
LR  - 20210809
IS  - 1097-6841 (Electronic)
IS  - 0022-3913 (Linking)
VI  - 126
IP  - 2
DP  - 2021 Aug
TI  - Influence of build angulation on the mechanical properties of a direct-metal 
      laser-sintered cobalt-chromium used for removable partial denture frameworks.
PG  - 224-230
LID - S0022-3913(20)30423-6 [pii]
LID - 10.1016/j.prosdent.2020.06.014 [doi]
AB  - STATEMENT OF PROBLEM: Direct-metal laser-sintering (DMLS) technologies are being 
      used to manufacture removable partial denture frameworks; however, the build 
      parameters are not well documented. PURPOSE: The purpose of this in vitro study 
      was to investigate the impact of 3 different build angulations on a dental 
      cobalt-chromium (Sint-Tech ST2724G) alloy by comparing the tensile properties and 
      nanoindentation hardness. The null hypothesis was that no change would be found 
      in the tensile properties of the different build angulation groups. MATERIAL AND 
      METHODS: Dumbbell-shaped tensile specimens were produced by using 
      stereolithographic models in accordance with American Society for Testing and 
      Materials testing standard E8/E8M-16ae1. Specimens (n=10) were fabricated by 
      using DMLS additive manufacturing with 3 different angulations (0, 45, and 90 
      degrees). Tensile testing was carried out to assess yield strength (0.2% 
      permanent offset), elongation (%) at failure, and ultimate tensile strength 
      (GPa). Scanning electron microscope (SEM) images were used to analyze the 
      fracture surfaces. One 10x10x10 mm cube specimen at each orientation was 
      prepared, and nanoindentation was used to determine hardness and elastic modulus. 
      One-way ANOVA was used to evaluate the overall effects with interaction between 
      groups and post hoc testing applied where the interaction was statistically 
      significant (alpha=.05). RESULTS: The 45-degree build angulation resulted in the 
      lowest mean elastic modulus of 213.3 GPa and the highest tensile strength of 
      1180.9 MPa. The 90-degree build angulation resulted in the highest mean 
      elongation of 10.6% and the highest elastic modulus of 234.0 MPa. Within 
      comparison of the different angulations indicated that various groups had 
      statistically significant differences (P<.05). The SEM analysis indicated 
      different fracture topography among the different build angles. CONCLUSIONS: The 
      cobalt-chromium dental alloy manufactured by DMLS produced favorable mechanical 
      properties. The SEM analysis combined with the tensile test results suggest that 
      the direction of the build angle in relation to the laser melt pattern does 
      impact the mechanical properties of the alloy.
CI  - Copyright (c) 2020 Editorial Council for the Journal of Prosthetic Dentistry. 
      Published by Elsevier Inc. All rights reserved.
FAU - Aarts, John M
AU  - Aarts JM
AD  - Senior Lecturer, Faculty of Dentistry, Sir John Walsh Research Institute, 
      University of Otago, Dunedin, New Zealand. Electronic address: 
      john.aarts@otago.ac.nz.
FAU - Choi, Joanne Jung Eun
AU  - Choi JJE
AD  - Lecturer, Faculty of Dentistry, Sir John Walsh Research Institute, University of 
      Otago, Dunedin, New Zealand.
FAU - Metcalfe, Steven
AU  - Metcalfe S
AD  - Director, Research and Development Division, Additive Manufacture Solutions Ltd, 
      Lower Hutt, New Zealand.
FAU - Bennani, Vincent
AU  - Bennani V
AD  - Associate Professor, Faculty of Dentistry, Sir John Walsh Research Institute, 
      University of Otago, Dunedin, New Zealand.
LA  - eng
PT  - Journal Article
DEP - 20200904
PL  - United States
TA  - J Prosthet Dent
JT  - The Journal of prosthetic dentistry
JID - 0376364
RN  - 0 (Chromium Alloys)
RN  - 0R0008Q3JB (Chromium)
RN  - 3G0H8C9362 (Cobalt)
SB  - IM
MH  - Chromium
MH  - Chromium Alloys
MH  - Cobalt
MH  - *Denture, Partial, Removable
MH  - Humans
MH  - Lasers
MH  - Materials Testing
MH  - Surface Properties
MH  - Tensile Strength
EDAT- 2020/09/08 06:00
MHDA- 2021/08/10 06:00
CRDT- 2020/09/07 05:31
PHST- 2019/11/13 00:00 [received]
PHST- 2020/06/06 00:00 [revised]
PHST- 2020/06/08 00:00 [accepted]
PHST- 2020/09/08 06:00 [pubmed]
PHST- 2021/08/10 06:00 [medline]
PHST- 2020/09/07 05:31 [entrez]
AID - S0022-3913(20)30423-6 [pii]
AID - 10.1016/j.prosdent.2020.06.014 [doi]
PST - ppublish
SO  - J Prosthet Dent. 2021 Aug;126(2):224-230. doi: 10.1016/j.prosdent.2020.06.014. 
      Epub 2020 Sep 4.