TRANSMISSION ELECTRON-MICROSCOPIC STUDY OF IN-VIVO PELLICLE FORMATIONON DENTAL RESTORATIVE MATERIALS

This electron microscopic investigation was performed to examine the u ltrastructure of the in vivo formed salivary pellicle on 15 different dental materials. Test pieces of amalgam alloys, casting alloys, titan ium, ceramics, resins, composite resins, glass polyalkenoate cement, a nd bovine enamel were attached to the buccal and lingual surfaces of t he upper first molars in three adults using removable intraoral splint s. The splints were carried over periods of 2 and 6 h. Pellicle-like s tructures could be identified on all tested material surfaces by trans mission electron microscopic analysis. The pellicle layer showed a hig h degree of similarity on different kinds of surfaces with regard to t he ultrastructural appearance. However, distinct differences could be detected in the ultrastructural pattern and thickness of the pellicle layer formed on buccally and lingually mounted specimens. Pellicles ad sorbed on buccally carried test pieces were characterized by a heterog eneous, globular appearance and a thickness ranging from 500 to 1,000 nm after 6 h. In contrast, all lingually mounted test pieces were cove red by a granular pellicle of about 100 nm thickness after 6 h. It is concluded that the ultrastructural pattern and extent of salivary pell icle formation are influenced by locally available salivary biopolymer s and locally effective shearing forces rather than by material-depend ent parameters.