Effects of incorporation of 2.5 and 5 wt% TiO₂ nanotubes on fracture toughness, flexural strength, and microhardness of denture base poly methyl methacrylate (PMMA)
	    		
		   		
		   			
		   		
	    	
    	 
    	10.4047/jap.2018.10.2.113
   		
        
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Sahar ABDULRAZZAQ NAJI
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Marjan BEHROOZIBAKHSH
			        		
			        		;
		        		
		        		
		        		
			        		Tahereh Sadat JAFARZADEH KASHI
			        		
			        		;
		        		
		        		
		        		
			        		Hossein ESLAMI
			        		
			        		;
		        		
		        		
		        		
			        		Reza MASAELI
			        		
			        		;
		        		
		        		
		        		
			        		Hosseinali MAHGOLI
			        		
			        		;
		        		
		        		
		        		
			        		Mohammadreza TAHRIRI
			        		
			        		;
		        		
		        		
		        		
			        		Mehrsima GHAVVAMI LAHIJI
			        		
			        		;
		        		
		        		
		        		
			        		Vahid RAKHSHAN
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. Foundation of Technical Education, College of Health & Medical Technology, Baghdad, Iraq.
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:Original Article
 
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		Titania nanotubes;
			        		
			        		
			        		
				        		Denture base resin;
			        		
			        		
			        		
				        		Poly methyl methacrylate (PMMA);
			        		
			        		
			        		
				        		Fracture toughness;
			        		
			        		
			        		
				        		Flexural strength;
			        		
			        		
			        		
				        		Vickers microhardness
			        		
			        		
	        			
        			
        		
 
        	
            
            	- MeSH:
            	
	        			
	        				
	        				
				        		
					        		Denture Bases;
				        		
			        		
				        		
					        		Dentures;
				        		
			        		
				        		
					        		Hardness;
				        		
			        		
				        		
					        		Nanotubes;
				        		
			        		
				        		
					        		Polymethyl Methacrylate
				        		
			        		
	        			
	        			
            	
            	
 
            
            
            	- From:The Journal of Advanced Prosthodontics
	            		
	            		 2018;10(2):113-121
	            	
            	
 
            
            
            	- CountryRepublic of Korea
 
            
            
            	- Language:English
 
            
            
            	- 
		        	Abstract:
			       	
			       		
				        
				        	PURPOSE: The aim of this preliminary study was to investigate, for the first time, the effects of addition of titania nanotubes (n-TiO2) to poly methyl methacrylate (PMMA) on mechanical properties of PMMA denture base. MATERIALS AND METHODS: TiO2 nanotubes were prepared using alkaline hydrothermal process. Obtained nanotubes were assessed using FESEM-EDX, XRD, and FT-IR. For 3 experiments of this study (fracture toughness, three-point bending flexural strength, and Vickers microhardness), 135 specimens were prepared according to ISO 20795-1:2013 (n of each experiment=45). For each experiment, PMMA was mixed with 0% (control), 2.5 wt%, and 5 wt% nanotubes. From each TiO2:PMMA ratio, 15 specimens were fabricated for each experiment. Effects of n-TiO2 addition on 3 mechanical properties were assessed using Pearson, ANOVA, and Tukey tests. RESULTS: SEM images of n-TiO2 exhibited the presence of elongated tubular structures. The XRD pattern of synthesized n-TiO2 represented the anatase crystal phase of TiO2. Moderate to very strong significant positive correlations were observed between the concentration of n-TiO2 and each of the 3 physicomechanical properties of PMMA (Pearson's P value ≤.001, correlation coefficient ranging between 0.5 and 0.9). Flexural strength and hardness values of specimens modified with both 2.5 and 5 wt% n-TiO2 were significantly higher than those of control (P≤.001). Fracture toughness of samples reinforced with 5 wt% n-TiO2 (but not those of 2.5% n-TiO2) was higher than control (P=.002). CONCLUSION: Titania nanotubes were successfully introduced for the first time as a means of enhancing the hardness, flexural strength, and fracture toughness of denture base PMMA.