An electron microscopic study of the acquired pellicle and plaque formed on the enamel of human incisors

Abstract

The acquired pellicle formed on the approximal, labial and lingual surfaces of human incisors has been examined in the electron microscope. The characteristics of the pellicle were different on the three surfaces. The approximal surface was penetrated by the pellicle to form a “dendritic” structure for several microns below the enamel surface and the pellicle itself was penetrated by the dental plaque. The labial surface contained pellicle that was relatively thicker and more free from plaque compared with the approximal surface. A laminated calcification and differential staining with silver, approximately parallel to the enamel surface, was occasionally observed in the pellicle on the labial surface. The pellicle on the lingual surface was always observed to be calcified to some degree. There was no evidence of penetration of the pellicle into either the labial or the lingual surfaces of the enamel. Histochemical staining showed the presence of both carbohydrate and protein in the pellicle of all surfaces.