Effects of immediate and delayed light activation on the polymerization shrinkage-strain of dual-cure resin cements.
	    		
		   		
		   			
		   		
	    	
    	 
    	10.4047/jkap.2014.52.3.195
   		
        
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		So Yeoun LEE
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Sung Hun KIM
			        		
			        		;
		        		
		        		
		        		
			        		Seung Ryong HA
			        		
			        		;
		        		
		        		
		        		
			        		Yu Sung CHOI
			        		
			        		;
		        		
		        		
		        		
			        		Hee Kyung KIM
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. School of Dentistry, Seoul National University, Seoul, Republic of Korea.
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:Original Article
 
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		Dual-cure resin cement;
			        		
			        		
			        		
				        		Polymerization shrinkage-strain;
			        		
			        		
			        		
				        		Light activation
			        		
			        		
	        			
        			
        		
 
        	
            
            	- MeSH:
            	
	        			
	        				
	        				
				        		
					        		Polymerization*;
				        		
			        		
				        		
					        		Polymers*;
				        		
			        		
				        		
					        		Resin Cements*
				        		
			        		
	        			
	        			
            	
            	
 
            
            
            	- From:The Journal of Korean Academy of Prosthodontics
	            		
	            		 2014;52(3):195-201
	            	
            	
 
            
            
            	- CountryRepublic of Korea
 
            
            
            	- Language:Korean
 
            
            
            	- 
		        	Abstract:
			       	
			       		
				        
				        	PURPOSE: This study was designed to compare the amount of polymerization shrinkage of dual-cure resin cements according to different polymerization modes and to determine the effect of light activation on the degree of polymerization. MATERIALS AND METHODS: Four kinds of dual-cure resin cements were investigated: Smartcem 2, Panavia F 2.0, Clearfil SA Luting and Zirconite. Each material was tested in three different polymerization modes: self-polymerization only, immediate light polymerization and 5 minutes-delayed light polymerization. The time-dependent polymerization shrinkage-strain was evaluated for 30 minutes by Bonded-disk method at 37degrees C. Five recordings of each material with three different modes were taken. Data were analyzed using one-way ANOVA and multiple comparison Scheffe'test (alpha=.05). RESULTS: All materials, except Panavia F 2.0, exhibited the highest polymerization shrinkage-strain through delayed light-activated polymerization. No significant difference between light activation modes was found with Panavia F 2.0. All materials exhibited more than 90% of polymerization rate in the immediate or delayed light activated group within 10 minutes. CONCLUSION: As a clinical implication of this study, the application of delayed light activation mode to dual-cure resin cements is advantageous in terms of degree of polymerization.