添加有机染料后玻璃离子水门汀的性能

Properties of glass ionomer cements after addition of organic dye solutions

背景:临床中对牙体轴壁缺损病例进行根管治疗时,可通过制作假壁隔离口腔环境对根管系统的污染,为橡皮障的固位提供有利条件。但现有假壁材料颜色与牙体组织趋于一致,常造成后期拆除时牙体组织的损失。因此赋予假壁材料鲜明的颜色使其能够区别于牙体组织具有显著的临床应用意义。目的:比较加入3种有机染料前后增强型玻璃离子水门汀假壁材料的理化性能及机械性能。方法:实验组将不同浓度(1%,2%)的亚甲基蓝、结晶紫、赤藓红染液分别添加至玻璃离子水门汀液剂中,调拌玻璃离子水门汀制作试件,并以未添加染液的玻璃离子水门汀试件为对照组。测试材料的固化时间,观察试件的宏观及微观表面形貌,检测其吸水值和溶解值,并使用Instron万能测试机检测试件的压缩强度。同时,将玻璃离子水门汀试件与牙本质进行粘接,观察粘接界面垂直剖面形貌,检测剪切粘接强度,记录粘接界面断裂模式。结果与结论:(1)各组试件的固化时间比较无差异,实验组试件颜色与对照组有明显差异,各组试件表面微观结构无差异;(2)各组试件吸水值比较无差异,实验组试件的溶解值高于对照组(P<0.05);(3)玻璃离子水门汀试件浸泡于人工唾液中1,7 d后,各组试件压缩强度比较差异无显著性意义;(4)与牙本质粘接后,实验组材料与牙本质紧密贴合,粘接界面连续紧密,无明显裂隙、裂纹及气泡,无有染料渗入到牙本质小管中;(5)将粘接试件浸泡于人工唾液中7 d后,各组剪切粘接强度比较差异无显著性意义;试件断裂模式主要为内聚破坏与混合破坏;(6)结果表明,添加1%或2%的亚甲基蓝、结晶紫、赤藓红染液对玻璃离子水门汀有较明显的染色作用,但对其理化、机械性能影响较小,提示染色后的玻璃离子水门汀可作为假壁材料应用于根管治疗过程中。

BACKGROUND： A wall build-up prior to endodontic therapy is applied to prevent contamination of the root canals from oral cavity and to provide retention for rubber dam when root canal treatment is required to badly broken-down tooth which have lost the integrity of the external coronal tooth structure in clinical practice. However, the color of the available wall build-up materials is consistent with the tooth tissue, which often causes the loss of tooth tissues during the removal in later prosthetic phase. Therefore, it is advisable to endue materials with a distinct color that makes it chromatically different from the tooth tissue, which is of great clinical significance. OBJECTIVE： To compare the effect of three organic dye solutions on physicochemical and mechanical properties of reinforced glass ionomer cements （GIC） which used as wall build-up material. METHODS： Different concentrations of methylene blue, crystal violet, erythrosine dye solutions （1%, 2%） were dispersed to the liquor of glass ionomer cements respectively as experiment groups, whereas the undyed glass ionomer cements were taken as control group. The setting time was measured in each group according to the occupation standard. The macro/micro surface topographical features of all the glass ionomer cement specimens were investigated. Meanwhile, water sorption and solubility were assessed. The compressive strength of the specimens was determined using a universal testing machine （Instron）. The specimens were then attached to the dentin and the vertical section of the bonding interface between the glass ionomer cement and the dentin was observed using endodontic microscope. Shear bond strength and failure mode of the specimens were also determined.RESULTS AND CONCLUSION： （1） There was no significant difference in the setting time among groups. The appearance of the specimens in the experiment groups was chromatically different from those in the control group, whereas the microscopic surface morphology of the specimens were insignificantly different. （2） In comparison to the control group, incorporation of organic dye solutions to the glass ionomer cements increased the solubility （P 〈 0.05）, but the water absorption showed no significant difference in all groups. （3） The compressive strength of the specimens that had been immersed in the artificial saliva for 1 and 7 days in all groups showed no significant difference. （4） The dyed specimens in the experiment groups were tightly bonded to the dentin and the boding interface was continuous with no obvious fractures, cracks and bubbles. Penetration into dentinal tubules of organic dye solutions was not observed. （5） The shear bond strength of the specimens that had been immersed in the artificial saliva for 7 days in all groups showed no significant difference. The failure modes of the specimens mainly included cohesive failure and mixed failure. Our findings reveal that the glass ionomer cements can be obviously stained by methylene blue, crystal violet and erythrosine at a concentration of 1% or 2%, whereas physicochemical and mechanical properties of the glass ionomer cements are less altered, indicating the dyed glass ionomer cements can be used during root canal therapy as a wall build-up material.