The Experimental Study on Wear Resistance of the Denture Base Material Reinforced with Graphene Oxide

To make enhancement on high hardness, hydrophilicity and the wear resistance for denture base composite materials, polymethyl methacrylate (PMMA) and graphene oxide (GO) were mixed successfully by the step of liquid-phase ultrasonication dispersion, high-speed ball mill mixing, and finally the samples of denture base reinforced with GO were processed according to the processing method of dental conventional method. The microstructure, micro-hardness and the surface hydrophilic of the GO/PMMA composites were observed and evaluated by using a high-resolution scanning electron microscope, Vicker micro-hardness meter and the contact angle analysis apparatus. Under the lubrication of artificial saliva, the wear properties of the GO/PMMA composites were investigated using a reciprocating friction testing apparatus of UMT-3MT. The surface topographies and their wear scratches of these composites were observed by Micro-XAM three-dimensional surface profile. The results show that compared with the routine denture base material,the micro- hardness of GO/PMMA composites increased with the increasing GO content. However, the trend became weaker when the addition amount of GO was greater than 0.1%. The static contact angle decreased gradually with the addition amount of GO. When the addition amount of GO was lower than 0.1%, the coefficient of friction and wear rate of these composites were lower than the control group, while the addition was higher than 0.1%, the results were reversed. The wear resistance of GO/PMMA composites were enhanced by the addition of the enhance filler of GO. The denture base material reinforced with GO shows good properties for dental clinical application.