Evaluation of corrosion resistance of Co-Cr alloys fabricated with different metal laser sintering systems
	    		
		   		
		   			
		   		
	    	
    	 
    	10.4047/jap.2020.12.3.114
   		
        
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Süleyman Hakan TUNA
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Erhan KARACA
			        		
			        		;
		        		
		        		
		        		
			        		İsmail ASLAN
			        		
			        		;
		        		
		        		
		        		
			        		Gürel PEKKAN
			        		
			        		;
		        		
		        		
		        		
			        		Nuran Özçiçek PEKMEZ
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. Department of Prosthodontics, Faculty of Dentistry, Süleyman Demirel University, Isparta, Turkey
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:Original Article
 
        	
        	
            
            
            	- From:The Journal of Advanced Prosthodontics
	            		
	            		 2020;12(3):114-123
	            	
            	
 
            
            
            	- CountryRepublic of Korea
 
            
            
            	- Language:English
 
            
            
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		        	Abstract:
			       	
			       		
				        
				        	 PURPOSE:. The aim of this study was to evaluate the corrosion resistance of the specimens produced by five different commercial metal laser sintering (MLS) systems with their recommended Co-Cr alloy powders. 
				        	
				        
				        	MATERIALS AND METHODS:. The MLS machines and the alloy powders used were, ProX 100-ST2724G (St-Pro), Mysint 100-EOS SP2 (SP2-Mys), EOSINT 270-EOS SP2 (SP2-EOS), SLM 100-Starbond CoS (SB-SLM), and MLab Cusing-Remanium® Star (RS-MLab), respectively. Eight specimens from each group were prepared. Open circuit potential (Eocp) and electrochemical impedance spectroscopy (EIS) measurements of polished surfaces of the specimens were conducted in a three-electrode cell using a potentiostat-galvanostat in Fusayama-Meyer artificial saliva (AS). Specimens from each group were immersed in AS and de-ionized water for seven days. Eocp, charge transfer resistance (Rct) values, and released ions (μg/cm2 × 7d) in different solutions were determined. The specimen surfaces were observed with SEM/EDS. Results were analyzed statistically.  
				        	
				        
				        	RESULTS:. Eocp values have shifted to potentials that are more positive over time. Steady-state Eocp values were from high to low as follows, SB-SLM, SP2-Mys, SP2-EOS, RS-MLab, and ST-Pro, respectively. After 60 mins, RS-MLab specimens had the highest Rct value, followed by SP2-Mys, SB-SLM, SP2-EOS, and ST-Pro. In all groups, ion release was higher in AS than that in de-ionized water.  
				        	
				        
				        	CONCLUSION:. There were small differences among the corrosion resistances of the Co-Cr alloy specimens produced with MLS systems; meanwhile, the corrosion resistances were quite high for all specimens.