| Composite resin is a regularly used material to restore dental and dentition defect and for dental aesthetic. But its application has been limited due to discoloration, easily aging, lower flexible strength, bad toughness and as a result the life-span is short. With the development of physical and chemical theory and associated technique, especially progress of nano-technology, it is becoming increasingly popular to improve the property of composite resin by adding nano-particle. In this study, we use home-produced multi-micropore nano-SiO2 particle and α-Si3N4 wisker as filler to investigate the property of composite resin. First the multi-micropore nano-SiO2 particle was fused and attached onto the surface of α-Si3N4 wisker through high temperature, then polymerized with BIS-GMA resin under various silicade condition, and compared with available composite resin such as Artglass and Composan LCM. The aim of our study is to develop a dental composite resin with higher flexible strength, stronger toughness and lower brittleness, and to promote the home-made course of dental material as well as the success rate of dental prosthetic and effect of dental aesthetic. Our study includes three parts: Effect of chemo-physics factor on filler structureThe chemical radicals of filler surface affect the silicade effect of filler and determine composite resin performance. In order to achieve optimal interface structure between filler and resin and improve performance of composite resin ready to make, we adopted Fuliye infrared spectrograph, X-ray diffraction apparatus, granularity assay instrument and scanning electron microscope, etc, to investigate the variation of surface chemical radicals and chemical structure of multi-micropore nano-SiO2 particle and α-Si3N4 wisker under various temperature and time of fusion and attachment, as well as the shape after fusion and attachment of above materials. It was showed that the Si-OH of multi-micropore nano-SiO2 particle surface was fully detached when it was fused for 10 min and 30 min at a temperature of 950℃ and for 3h at a temperature of 650℃; there was no change of structure and surface chemical radicals of α-Si3N4 wisker. Nano-SiO2 particle and α-Si3N4 wisker were fused and attached mainly by Si-O-Si bond, and so did between multi-micropore nano-SiO2 particle. It was indicated that temperature and time of fusion and attachment determined Si-OH content of multi-micropore nano-SiO2 particle surface , and the shape and granularity distribution of composite filler, etc.Silicade degree of filler surface influenced the combination degree between filler and resin matrix, and also was an important factor of determining composite resin property. In order to achieve optimal silicade effect of filler surface and improve integration of filler and matrix, we adopted Fuliye infrared spectrograph, granularity assay instrument and transmission electron microscope, etc, and constant cyclohexane and n-propylamine as disperse medium and promoter respectively , γ-MPS as siliconize agent, to investigate the effect of filler surface siliconize by various addingγ-MPS methods and its mechanism of siliconize. The results showed thatγ-MPS could siliconize multi-micropore nano-SiO2 particle , α-Si3N4 wisker and fused α-Si3N4 - SiO2 efficiently; the mechanism of siliconize might be :Si-OH produced afterγ-MPS hydrolyzation combined with Si-OH of filler surface and formed Si-O-Si bond, and/or combined with carbonyl of silicon alkyl molecular to form hydrogen bond on filler surface, which indicated that equal concentration gradient ofγ-MPS could siliconize filler surface efficiently and further promote combination of filler and resin matrix.Development of nano- wisker-reinforced composite resinThe condition of fusion and attachment, proportion of α-Si3N4 wisker and multi-micropore nano-SiO2 particle and the proportion of nano-SiO2-α-Si3N4 wisker mixture and resin matrix affect composite resin performance. We mixed α-Si3N4 wisker and multi-micropore nano-SiO2 particle...
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