复合纳米银正畸粘接剂抗菌性和粘接强度的研究

Antibacterial Properties and Bond Strength of Experimental Nano Silver-containing Orthodontic Cements

目的:评价复合纳米银正畸粘接剂的长期抗菌活性和粘接强度。方法:将纳米银抗菌粉体以5种不同的比例加入增强型玻璃离子粘接剂(GC Fuji ORTHO LC;GC Corporation,Tokyo,Japan)中获得一系列复合纳米银正畸粘接剂(nano silver-containing cements,NSC),然后通过直接接触试验和琼脂扩散试验评价3种成品托槽粘接剂和五种复合纳米银正畸粘接剂样本的抗菌特性。同时,应用万能测力机就以上材料的粘接强度进行了测量。结果:琼脂扩散试验结果表明,新鲜的复合纳米银正畸粘接剂和增强型玻璃离子正畸粘接剂无差异性。在直接接触试验中,所有新鲜复合纳米银材料均呈现强抗菌性,但是随着老化时间的延长,其抗菌成分呈逐渐丧失的趋势。最后,所有测试的材料在老化8周后完全丧失抗菌活性。即便所有测试的材料均能满足临床粘接强度的要求,但是结果显示,随着纳米银抗菌粉体掺入比例的增加,粘接强度呈下降的趋势。结论:复合纳米银正畸粘接剂在不影响粘接强度的前提下有助于减少托槽周围牙釉质脱矿出现的几率。

Objective： To evaluate the long time antibacterial properties and shear bond strength of experimental nano silver--containing cements （NSC）. Methods： Nano silver base inorganic antibacterial powder was added to the reinforced glass ionomer cement （GC Fuji ORTHO LC; GC Corporation, Tokyo, Japan） at five different weight ratios to obtain a series of nano silver--containing cements, then the antibacterial properties of three orthodontic ce- ment products and five NSC samples were evaluated by direct contact test （DCT） and agar diffusion test （ADT）. The shear bond strength of three orthodontic cement products and five NSC samples was examined using a universal testing machine. Results： The result of ADT indicated that no significant differences between NSCs and ORTHO LC fresh specimens. In the DCT, all fresh silver nanoparticles--containing tested samples presented powerful antibacterial properties, but they gradually lost the effective antimicrobial agents with the extension of aging time. Finally, none of the tested materials maintained its antibacterial property after aging for 8 weeks. A gradually decreasing trend of bond strength presented with the increasing incorporation of nano silver base inorganic antibacterial powder into the glass ionomer cement, even though all the tested material specimens had reached the ideal bond strength range. Conclusion： We may conclude that NSCs can contribute to decrease the demineralization rate around brackets without compromising bond strength.