Comparison of Cariogenic Characteristics between Fluoride-sensitive and Fluoride-resistant Streptococcus mutans
	    		
		   		
		   			
		   		
	    	
    	 
    	10.5933/JKAPD.2020.47.4.397
   		
        
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Seung-Hwan ONG
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Jongsoo KIM
			        		
			        		;
		        		
		        		
		        		
			        		Dong-Heon BAEK
			        		
			        		;
		        		
		        		
		        		
			        		Seunghoon YOO
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. Department of Pediatric Dentistry, College of Dentistry, Dankook University, Cheonan, Republic of Korea
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:1
 
        	
        	
            
            
            	- From:
	            		
	            			Journal of Korean Academy of Pediatric Dentistry
	            		
	            		 2020;47(4):397-405
	            	
            	
 
            
            
            	- CountryRepublic of Korea
 
            
            
            	- Language:Korean
 
            
            
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		        	Abstract:
			       	
			       		
				        
				        	 The aim of this study is to compare cariogenic characteristics of fluoride-sensitive Streptococcus mutans [fluoride-sensitive (FS) S. mutans ] and fluoride-resistant Streptococcus mutans [fluoride-resistant (FR) S. mutans] in the presence of sucrose, and to evaluate its effect on cariogenic biofilm formation. S. mutans ATCC 25175 was continuously cultured in trypticase soy broth (TSB) containing NaF (70 ppm) for 40 days to generate FR S. mutans . FS and FR S. mutans were inoculated in TSB with or without 2% sucrose, and optical density and pH were measured every hour. An oral biofilm was formed using saliva bacteria and analyzed through confocal laser scanning microscopy and CFU count. Finally, the expression of glucosyltransferases genes of both S. mutans was investigated through RT-PCR. FR S. mutans exhibited slower growth and lower acidogenicity in the presence of sucrose compared to FS S. mutans . Both cariogenic and single species biofilm formation was lower in the presence of FR S. mutans , along with reduced number of bacteria. FR S. mutans showed significantly low levels of gtfB, gtfC, and gtfD expression compared to FS S. mutans . On the basis of results, FR S. mutans may be less virulent in the induction of dental caries.