title: Influence of shearing action of food on contact stress and subsequent wear of stress-bearing composites.
abstract: The influence of sliding action of the antagonist on occlusal three-body wear of composites and an amalgam was investigated in vitro by gradual change in the distance between the opposing substrates. When the distance was decreased from 10 microns to approximately 3 microns, wear increased significantly by a factor of two to three and was exclusively of erosive nature. At a slurry-film thickness of approximately 1 micron, direct contacts between the antagonist and protruding composite filler particles started to occur. This consequently slowed the erosive wear. Ultimately, direct contact phenomena predominated, decreasing the wear rate of the various materials to different degrees. Loss of material due to subsurface fatigue could not be demonstrated with a contact pressure of 45 MPa at which the experiments were performed. From this study, it can be concluded that minor alterations of the food-film thickness at the contact areas result in considerable changes in wear rates and wear-rate ranking of composite materials, which may partly explain inconsistencies among clinical trials.
authors.affiliation: ACTA (Academic Centre for Dentistry Amsterdam), Department of Dental Materials Science, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Pallav
authors.forename: A J
authors.initials: AJ
authors.lastname: de Gee
authors.forename: A
authors.initials: A
authors.lastname: Werner
authors.forename: C L
authors.initials: CL
authors.lastname: Davidson
mesh_terms: D003188:Composite Resins; D003799:Dental Stress Analysis / Q000295:instrumentation; D005502:Food; D006801:Humans; D008409:Mastication; D008422:Materials Testing / Q000295:instrumentation; D012275:Oryza; D013499:Surface Properties
chemical_list: D003188:Composite Resins