Composition of pellicles formed in vivo on tooth surfaces in different parts of the dentition, and in vitro on hydroxyapatite

Saliva from the major salivary glands dominates different areas of the mouth. The parotid (PS) and submandibular/sublingual (SMS) saliva differ in their protein composition, and thus, the composition of pellicles formed in various parts of the dentition might vary. In this study, proteins incorporated in 60-min pellicles from the premolar and front regions of the mouths of 4 subjects were examined using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunoblotting using antibodies to amylase, albumin, IgA, parotid saliva agglutinin, low molecular weight SMS mucin (MG2) and proline-rich proteins. Pellicles formed in Vitro on hydroxyapatite using PS, SMS and whole saliva from the subjects were examined in a similar manner. The pellicles formed in Vitro and in vivo showed a major difference in the appearance of albumin. Bands of albumin were clearly stained in the samples of in vivo pellicles but were not observed or hardly visible in Western blots from the experimental, in vitro pellicles. The sites in the dentition from which a specific protein was recovered could differ between the 4 individuals. The overall protein pattern of the pellicles showed, however, characteristics typical of the saliva which may prevail in the part of the mouth where the pellicles were formed. Thus, parotid saliva agglutinin, a receptor for Streptococcus mutans, was primarily found in the premolar part of the dentition. The mucin MG2, which may mediate the adherence of Streptococcus sanguis and Streptococcus oralis, was in no case clearly seen in pellicles from the premolar region of the upper jaw. The observed variations might be important to the establishment of microflora and tooth-related disease patterns in various parts of the dentition.