【摘要】 目的:观察用37%磷酸凝胶以不同酸蚀时间处理后的牙釉质在牙齿横断面上的形态改变。方法:选取因正畸需要拔除的健康上颌第一前磨牙30个,随机分为3组,每组10个。分别用37%磷酸凝胶,以15s、30s、60s时间对颊面进行处理。用扫描电镜对牙齿横断面上釉质形态改变进行观察,并对改变的深度进行测量分析。结果:不同时间酸蚀后的釉质均表现为沿釉柱方向的溶解,但各组的溶解程度不同,15s组表现为间断的,深浅不一的溶解,30s组和60s组则表现为连续的、较均匀一致的溶解。在60s内,平均酸蚀深度随处理时间延长而加深。结论:釉质酸蚀后在牙齿横断面上的形态表现较为单一。15s组比30s组和60s组的溶解形态出现的密度低。更多还原

【Abstract】 Objective:To investigate the appearance of enamel on the cross section of tooth after etched with 37% phosphoric acid for different etching time .Method: Thirty sound maxillary first premolar extracted for orthodontic reasons was collected and divided randomly into three groups of ten . The buccal surface of teeth were etched with 37% phosphoric acid for 15 , 30 , or 60 seconds . After etched the teeth were cut horizontally from the midpoint of clinical crown with the long axis vertically . Then the etched pattern of enamel on the teeth cross section was examined under the scanning electron microscope (SEM), and the depth of changes measured and analyzed . Result : The enamel dissolved along prism in all three groups , but the density of dissolution of each group was different . 15 second group appears disconnected dissolution , 30 and 60 second groups appear connected and uniformed dissolution .Within 60 second , the depth of etch increased with the etch time extend .Conclusion:The pattern of enamel on cross section after etched with phosphoric acid was not divers. 30 and 60 second groups appear denser dissolution than 15 second group.更多还原