釉质酸蚀后牙面脱矿与再矿化的扫描电镜观察

目的:观察牙釉质酸蚀后在离体状态下和一段时间内在口腔环境中的结构变化,探讨牙釉质脱矿与再矿化的形态学改变.方法:选择因正畸需要拔除健康第一前磨牙病例10例,40个牙,使用YY0269-1995型酸蚀剂对拟拔除的第一前磨牙颊侧釉质酸蚀60 8,左侧上、下颌第一前磨牙为A组,A组再分为A1、A2组,A1组酸蚀后即刻拔除,制作扫描电镜观察标本,A2组,第一前磨牙酸蚀后即刻拔除,置37℃恒温蒸馏水中浸泡1个月后制作电镜标本观察.右侧上、下颌第一前磨牙为B组,第一前磨牙酸蚀后在口内存留1个月后拔除,用相同的方法进行观察,并比较A、B两组牙釉质形态学变化.结果:A组的牙釉质表面松软,不规则,多孔隙,表面呈蜂窝状改变;B组的牙釉质表面有大量矿物质沉积,孔隙变小,矿化物颗粒细小,沉积不均匀.结论:牙釉质脱矿后,在口腔环境中可发生再矿化,但矿化程度是有限的,提示在临床上应注意酸蚀时间及酸蚀范围.

An SEM observation of demineralization and remineralization on the teeth surface after enamel etched with acid etching agent

Objective:To investigate the morphologic change of demineralization and remineralization of teeth enamel by observing the structure change of enamel which is etched. Some teeth are excised and others stay in the buccal environment for a period of time.Method:Ten groups of healthy first premolar extracted for orthodontic reasons were collected.There were four teeth in each group. The buccal surface of teeth were etched with YY0269-1995 orthodontic acid etching agent for 60 seconds.The case was separated into tow groups.The first premolars of one side were group A and were extracted immediately for SEM observations. The first premolars of the other side were group B and were still in the oral cavity until they were extracted after one month and observed group B with the same method. To compare the morphologic change between A and B under the SEM.Result:The surface of the enamel of group A was loose,irregular and had more small openings.The surface was alveolate.On the surface of the enamel of group B,a lot of minerals deposited.The small openings were smaller.The minerals were exiguous and the aggradation was asymmetrical.Conclusion:After demineralization,although there might be the function of remineralization on enamel surface in oral cavity,it was limited.It is pointed out that the time and limit of etching shoud be paid special attention in clinical practice.