title: [An in vitro model for the simulation of approximal wear].
abstract: Several methods have been developed to evaluate attritional wear of restorative materials. A distinction was made between attritional wear in occlusal contact areas (OCA) and wear in contact-free occlusal areas (CFOA). Only limited data dealing with approximal wear in vitro are available. Using a new configuration of the computer-controlled masticator, approximal wear of two composites (P-50, 3M and Tetric Ceram, Ivoclar-Vivadent) was assessed in a two-body wear test after thermo-mechanical loading. Wear was quantified using a profilometer. In addition, micromorphology was assessed by SEM. Wear showed a non-linear pattern, which was comparable to occlusal abrasion. After the first loading cycle, wear increased significantly (p < or = 0.05), and subsequently decreased. After a 5-year-equivalent, the mean substance loss for composite specimens was 20.3 +/- 15.6 microns for P-50 und 17.5 +/- 3.1 microns for Tetric Ceram. Approximal wear between enamel surfaces was 3.9 +/- 4.3 microns. In another experiment, the influence of the approximal wear on an enamel bonding agent was assessed. After thermo-mechanical loading, specimens were immersed in a demineralisation gel. The protective potential of the sealant was assessed under a polarized light microscope. The results suggested that partial sealant loss could lead to caries-like demineralisation in the affected areas.
authors.affiliation: Zentrum für Zahn-, Mund- und Kieferheilkunde, Universität Zürich, Klinik für Päventivzahnmedizin, Parodontologie und Kariologie, Plattenstrasse 11, CH-8028 Zürich.
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Schmidlin
authors.forename: Tibor
authors.initials: T
authors.lastname: Pasqualetti
authors.forename: Thomas
authors.initials: T
authors.lastname: Imfeld
authors.forename: Mario
authors.initials: M
authors.lastname: Besek
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins; D003743:Dental Enamel / Q000473:pathology; D019554:Dental Restoration Wear; D003799:Dental Stress Analysis / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008409:Mastication; D008422:Materials Testing / Q000379:methods; D008855:Microscopy, Electron, Scanning; D008954:Models, Biological; D003765:Models, Dental; D008963:Molar; D013499:Surface Properties; D014072:Tooth Abrasion / Q000473:pathology*; D017001:Tooth Demineralization / Q000473:pathology
chemical_list: D003188:Composite Resins; C121818:Tetric ceram; C065771:P50 composite resin; D017438:Bisphenol A-Glycidyl Methacrylate