正常牙邻面釉质表面形态的扫描电镜观察

This observation was made on the proximal surfaces of normal permanent molars. Observations were concentrated mainly on those teeth with abraded contact areas on the mesial surface and the unabrasive distal surfaces if the partially or wholly embedded third molars. The results showed that the surfaces of the abraded contact areas were plain than those outside the contact. There were lots of pitted holes or fissures on the surfaces outside the contact areas. In the holes accumulations of bacteria could be seen. These holes and fissures could also be seen on the unexposed distal surfaces of the third molars, but no clear-defined traces of bacteria were observed in the holes.     

几种酸性胶液与蛋白解酶在人工龋形成的作用

Human tooth slabs were used to observe the effect of several kinds of organic acids and proteolytic enzymes on the production of artificial caries of enamel. Acidic gels were made by formic, acetic and lactic acids separately or in mixed form. The experiments were done in a period of 10 days. After this the specimens were prepared in ground sections and observed under optic microscope. The depth of the artificial lesions was measured by a micrometric scale in the eye lens of the microscope. The enzymes used for investigation were papain, trypsin and collagenase. The surfaces of the tooth were treated with fresh enzyme solutions every day and then with mixed acid gels. This was done alternately every day in a period of ten days. The results showed that lesions produced by formic acid gel were deeper than those produced by other acids or mixed acid gels. No effect was observed on the depth of the lesion by enzymatic treatments.