Effect of Treating Agents to the Exudation of Internal Fluids from Dentinal Tubules

用精密复制法对新鲜拔除的活体人牙本质小管渗出的内液进行了观察，并用扫描电子显微镜观察了酸蚀对磨牙本质表面渗出的影响。结果如下：1.在新鲜拔除的人牙本质表面和活体人牙本质表面观察到许多圆形突起。印模表面的圆形和小凹陷必须是在设置过程中牙本质小管内液体的渗出压力形成的，以表明这些圆形隆起的存在。结论：1.该方法能有效地观察牙本质小管内液在体内外的渗出情况。当使用快速固化时间为2min的印模材料时，未酸蚀的牙本质表面也出现渗出现象。使用快速固化时间为2min的印模材料时，未酸蚀牙本质表面渗出量随印模材料固化时间的延长而增加，而酸蚀后牙本质表面未观察到渗出物。当使用固化时间较长的印模材料时，在酸蚀的牙本质表面也可以观察到渗出。酸蚀去除玷污层的牙本质能有效延缓和减少牙本质小管内液的渗出。这些渗出的延迟和减少必须是有效的，以使树脂材料与牙本质有良好的粘附性。

Exudation of internal fluids from dentinal tubules on the freshly extracted and vital humans teeth was observed and the effect of etching to the exudation was studied on the ground dentin surfaces by SEM observation using precision replica method. Results were as follows :1. Many round prominences were observed on the dentin surfaces of the freshly extracted humans teeth and the vital humans teeth. The round and small concavities on the impression surfaces must be formed by the exuding pressure of the internal fluids from dentinal tubules during the setting to indicate the presence of these round prominences. This method was effective for observing the exudation of internal fluids from dentinal tubules in vitro and in vivo.2. The exudation was also observed on the unetched dentin surfaces when the impression material with fast setting time of 2 minutes was used. The quantity of exudation on the unetched dentin surfaces increased according to the prolonged setting time of the impression material But the exudation was not observed on the etched dentin surfaces when the impression material with the fast setting time of 2 minutes was used. The exudation was also observed on the etched dentin surfaces when the impression material with prolonged setting time was used. Etching of dentin to remove the smeared layr was effective to delay and lessen the exudation of internal fluids from dentinal tubules. These delay and decrescence of the exudation must be effective for the favorable adhesion of resinous materials to dentin.