唾液污染后再处理对窝沟封闭边缘封闭性能影响的研究

摘要

Objective To evaluate the factors in retreatment of saliva contamination on microleakage, penetration ability and AFM of pit and fissure sealants in vitro. Methods 50 extracted sound third molars of human mandible were randomly divided into nine groups with ten in each group. Occlusal surfaces of the teeth in all groups were prepared using a No 1/4 round carbide bur,etched with 35% phosphoric acid,rinsed and dried. In group A,fissure sealant was applied onto the surfaces directly and stayed for 30 s. In other molar groups,the enamel was treated with the following methods after contaminated with artificial saliva for 10 s; Group B,drying; Group C, water spraying and drying; Group D,water spraying,drying and etching; Group E,water spraying,drying and applying self-etch adhesive system. After these procedures, a fissure sealant was applied onto the surfaces of teeth in Group B-E and stayed for 30 s. Each tooth was subjected to thermal cycling (500 cycles at 5 -55 %!, ) with a dwell time of 30 seconds and dye immersion (1% methylene blue) for 24 hours. Microleakage and penetration ability were examined after sectioning. The quality of tag formation was examined u-sing an AFM ( Atomic Force Microscope). Results The penetration ability and microleakage in Group A and Group D were better than those of other groups (P < 0. 05). The results of AFM observation in saliva contamination group and self-etch adhesive group were obviously worse than other groups. Conclusions The findings revealed that saliva-contamination should be avoided strictly, and the contaminated tooth should be etched again. The findings didn't suggest using self-etching adhesive in clinical treatment as it had worse sealing ability.%目的 研究窝沟封闭唾液污染后再处理的操作因素对窝沟封闭剂微渗漏、渗透程度及其超微结构的影响.方法 取离体牙50颗,随机分成5组,每组10颗,每个样本咬合面窝沟处行窝沟釉质成形术,然后酸蚀,冲洗干燥.A组直接涂布封闭剂,停留30 s后光照固化.B～E组均经人工唾液污染牙面后,分别干燥、冲洗后干燥、冲洗干燥后再酸蚀和冲洗干燥后自酸蚀粘结剂处理,涂布封闭剂,停留30 s后光照固化.采用1％亚甲蓝浸染法和体视显微镜观察封闭剂与牙面间的密合程度及封闭剂的渗透程度.用原子力显微镜(atomic force microscope,AFM)观察各组窝沟封闭剂牙齿交界面的树脂形成情况.结果 未污染组和污染后再酸蚀组的微渗漏情况与渗透深度低于唾液污染后其他处理组(P＜0.05).原子力显微镜观察显示封闭剂-釉质交界面自酸蚀组树脂突稀疏不清晰,树脂突之间有混合层,唾液污染组树脂突较稀疏,长短不一,排列不规则,这2组的扫描结果差于未污染组.结论 唾液污染后应重新酸蚀处理,而使用自酸蚀粘结剂处理其密合性较差,临床不建议使用.