目的:比较桩道表面酸蚀处理对自粘接树脂水门汀Rely X Unicem与纤维桩之间粘接效果的影响。方法:选取36颗新鲜拔除的无龋坏单根管人前磨牙,常规根管充填与桩道预备后,使用磷酸酸蚀桩道,根据酸蚀时间的不同将试件随机分为3组(n=12):不酸蚀组(对照组,Et0)、酸蚀5秒组(Et5)、酸蚀20秒组(Et20)。各组试件粘接纤维桩后进行微推出粘接强度测试,扫描电镜(SEM)下观察粘接界面超微结构,X-射线能谱(EDX)分析粘接界面牙本质侧元素百分比含量。结果:Et0组微推出强度(8.27±1.88 MPa)显著高于Et5组(6.99±2.11 MPa)和Et20组(6.39±1.08 MPa),差异均有统计学意义(P<0.05)。Et5组微推出强度高于Et20组,但无统计学差异(P>0.05)。扫描电镜观察见Et20组单位视野内树脂突数量多于Et0组、Et5组。Et5组和Et20组中可见树脂水门汀与根管牙本质间存在裂隙。X-射线能谱分析显示,随着酸蚀时间的延长,粘接界面处牙本质中钙含量百分比呈逐渐下降的趋势。结论:桩道酸蚀处理不能促进自粘接树脂水门汀Rely X Unicem与纤维桩的粘接效果。
目的:探讨富含原花青素的葡萄籽提取物(grape seed extract,GSE)对两步法自酸蚀粘接系统即刻粘接性能的影响。方法:红外光谱测试不同浓度GSE预处理剂处理不同时间对Clearfil SE Bond双键转化率的作用,筛选最佳处理时间用于即刻微拉伸粘接强度测试,场发射扫描电镜观察断裂模式。结果:GSE浓度对双键转化率无显著影响,预处理40s组最高。各组间粘接强度无统计学差异,3%GSE组最高,以混合断裂为主。结论:3%GSE预处理40s可在不影响双键转化率的前提下一定程度上提高即刻粘接强度。
目的:评价表没食子儿茶素没食子酸酯(EGCG)及其甲基化修饰物(EGCG-3Me)改性粘接剂对根管牙本质粘接界面稳定性的作用。方法:将质量浓度为400μg/ml的EGCG及EGCG-3Me添加到全酸蚀粘接剂Single Bond 2(SB2)中,制备改性粘接剂E-SB2及E3-SB2,SB2为对照组。激光共聚焦显微镜和分光光度法检测改性粘接剂抗粪肠球菌的性能。微拉曼光谱仪检测粘接剂双键转化率。制备纤维桩粘接试件,用于即刻和老化后的微推出实验。结果:改性粘接剂可以抑制粪肠球菌生物膜形成,且EGCG-3Me作用更显著。改性粘接剂与SB2的双键转化率和即刻微推出粘接强度差异无显著性(P>0.05)。老化后改性粘接剂的微推出粘接强度显著高于SB2(P<0.05)。结论:EGCG和EGCG-3Me改性的粘接剂均可抑制粪肠球菌增殖并提高树脂-根管牙本质粘接界面稳定性,EGCG-3Me抗菌性能较佳。
Our previous studies showed that biomodification of demineralized dentin collagen with proanthocyanidin(PA) for a clinically practical duration improves the mechanical properties of the dentin matrix and the immediate resin–dentin bond strength. The present study sought to evaluate the ability of PA biomodification to reduce collagenase-induced biodegradation of demineralized dentin matrix and dentin/adhesive interfaces in a clinically relevant manner. The effects of collagenolytic and gelatinolytic activity on PA-biomodified demineralized dentin matrix were analysed by hydroxyproline assay and gelatin zymography. Then, resin-/dentin-bonded specimens were prepared and challenged with bacterial collagenases. Dentin treated with 2% chlorhexidine and untreated dentin were used as a positive and negative control, respectively. Collagen biodegradation, the microtensile bond strengths of bonded specimens and the micromorphologies of the fractured interfaces were assessed. The results revealed that both collagenolytic and gelatinolytic activity on demineralized dentin were notably inhibited in the PA-biomodified groups, irrespective of PA concentration and biomodification duration. When challenged with exogenous collagenases, PA-biomodified bonded specimens exhibited significantly less biodegradation and maintained higher bond strengths than the untreated control. These results suggest that PA biomodification was effective at inhibiting proteolytic activity on demineralized dentin matrix and at stabilizing the adhesive/dentin interface against enzymatic degradation, is a new concept that has the potential to improve bonding durability.
