Development of antibacterial composite resins containing photocatalysis titanium dioxide

以质量%分别为1、3、5、10、20、30的二氧化钛代替二氧化硅填料，在复合树脂中添加了3种粒径分别为6、30、180nm的光催化剂二氧化钛。观察了固化后的复合材料的抗压强度、直径拉伸强度和弯曲强度。通过大肠杆菌对其抑菌效果进行了研究，并通过扫描电镜和EPMA对其断口表面进行了观察，得到了以下结论：1)随着钛白粉掺量的增加，抗压强度呈下降趋势，当掺量超过20%时，抗压强度随钛白粉粒径的增加而下降。2)随着二氧化钛含量的增加，直径抗拉强度也呈现出类似的下降趋势，当粒径大于30nm时，粒径抗拉强度随添加量大于10%而下降。3)当掺入量超过20%时，抗弯强度迅速下降，且粒径越小，抗弯强度越大。4)观察了所有含二氧化钛的实验复合材料的抗菌效果，特别是含粒径大于30nm的氧化钛复合材料的抗菌效果显著。5)通过SEM和EPMA观察断口表面，二氧化钛的混合条件是均匀的。由此可见，含光催化剂二氧化钛的光固化复合树脂作为抗菌牙齿填充材料具有很大的潜力。

Three sort of photocatalyst titanium dioxide in different particle sizes of 6, 30, 180nm were added to the experimental composite resins by replacing the part of silica filler with 1, 3, 5, 10, 20, 30 mass%. The compressive strength, diametral tensile strength and bending strength of cured experimental composites was observed. The antibacterial effect was investigated by means of e. coli, and fracture surfaces were observed by SEM and EPMA, then the following conclusions were obatained.1) The compressive strength showed the tendency of decreasing when the contents of titanium dioxide increased, and in more than 20% the compressive strength decreased as the particle size of titanium dioxide increased.2) The diametral tensile strength showed the similar tendency of decreasing with the increase of titanium dioxide content, and when the particle size became more than 30nm, the diametral tensile strength decreased with the addition of more than 10%.3) The bending strength decreased rapidly with the addition of more than 20%, and the smaller the particle sizes became, the greater the bending strength became.4) The antibacterial effects were observed for all experimental composite containing titanium dioxide, especially the composites containing titanium oxide of particle size of more than 30nm showed significant antibacterial effect.5) From the observation of fracture surfaces by SEM and EPMA, the mixed conditions of titanium dioxide were homogeneous.From these observations, the light curing composite resins containing photocatalyst titanium dioxide have great potential as an antibacterial dental filling material.