醋酸氯己定复合介孔二氧化硅改性正畸粘接树脂的体外研究

目的探讨醋酸氯己定(chlorhexidine acetate,CHA)复合介孔二氧化硅改性正畸3M粘接树脂的抗菌性能和粘接强度。方法将不同质量分数的CHA包封于介孔二氧化硅纳米粒子(mesoporous silica nanoparticles,MSNs)中(记为CHA@MSNs),用傅里叶红外光谱仪和扫描电镜对实验所得样品进行表征分析。将3M Z350XT流动树脂分为4组,分别添加质量分数为0%、3%、5%、6.4%的CHA@MSNs,分别为A组:3M+CHA@MSNs(0%),B组:3M+CHA@MSNs(3%),C组:3M+CHA@MSNs(5%),D组:3M+CHA@MSNs(6.4%)。以万能电子材料试验机测试改性粘接剂的抗剪切强度;10倍放大镜观察牙面粘接剂残留,并计算牙面粘接剂残留指数(adhesive remnant index,ARI)。将4组改性粘接剂分别与变异链球菌共同培养,通过分光光度计测量菌液OD540值,扫描电镜观察菌斑附着量来评价粘接剂的抗菌性能。结果傅里叶红外光谱分析表明CHA已成功负载于MSNs之上;扫描电镜下可见CHA与MSNs结合后,MSNs结构...

In vitro study of chlorhexidine acetate compound mesoporous silica orthodontic modified binder resin

Objective The antibacterial properties and bonding strength of 3M orthodontic adhesive resin modified by chlorhexidine acetate(CHA)composite mesoporous silica were investigated.Methods CHA with different mass fractions was encapsulated in mesoporous silica nanoparticles(MSNs)(denoted CHA@MSNs).Fourier transform infrared spectroscopy(FTIR)and scanning electron microscopy(SEM)were used to characterize the samples.The 3M Z350XT flow resin was divided into 4 groups:group A:3M+CHA@MSNs(0%);group B:3M+CHA@MSNs(3%);group C:3M+CHA@MSNs(5%);and group D:3M+CHA@MSNs(6.4%),with mass scores of 0%,3%,5%,and 6.4%,respectively.The shear strength of the modified adhesive was tested by a universal electronic material testing machine,the adhesive residue was observed by a 10×magnifying glass,and the adhesive Remnant index(ARI)was calculated.The four groups of modified adhesives were cultured with Streptococcus mutans.The OD540 value of the bacterial solution was mea?sured by a spectrophotometer,and the amount of plaque attachment was observed by scanning electron microscopy to evaluate the antibacterial performance of the adhesives.Results Infrared spectroscopic analysis of CHA@MSNs showed that CHA was successfully loaded onto MSNs.Under scanning electron microscopy,it could be seen that,after Cha was combined with MSNs,the structure of MSNs changed,as the boundary was fuzzy and aggregated into a layered structure.A comparison of shear strength revealed a statistically significant difference between the groups containing CHA@MSNs and the groups without CHA@MSNs(P<0.05).The value of the shear strength in group D decreased the most,while there was no statistically significant difference between group B and group C(P>0.05).There was no statis?tical significance across all groups(P>0.05),suggesting that the addition of CHA@MSNs had little effect on the brack?et shedding.The OD540 value of bacterial fluid indicated that the difference among groups A,B and C was statistically significant(P<0.05),and the antibacterial effect of group C was the best;there was no statistically significant differ?ence between group C and group D(P>0.05).Conclusions Therefore,adding 5%CHA@MSN antibacterial agent sig?nificantly improved the antibacterial effect and did not affect the bond strength.