title: [In vitro fracture resistance tests of 3-unit posterior bridges produced by the Procera process].
abstract: The aim of this investigation was to evaluate the fracture resistance of three-unit fixed partial dentures manufactured with the Procera-System in vitro. Metal abutments representing the teeth 25 and 27 were prepared with a 90 degrees circumferential internally rounded shoulder. The abutments were duplicated with polyvinysiloxane, and master dies were fabricated. Using the Procera-System, 21 aluminiumoxid frameworks were manufactured. Twelve of these were veneered with porcelain in a standardized manner. All non-veneered and veneered frameworks were cemented on the original metal abutments and loaded to fracture. The mean fracture loads of the non-veneered and veneered frameworks were 477 N and 645 N, respectively. The Weibull modules of the test series were 4.7 for the non-veneered and 4.0 for the veneered frameworks. The in vitro results of this investigation seem to indicate that the use of fixed partial dentures manufactured with the Procera-System are clinically questionable. Furthermore, the low Weibull modules point to a limited fracture predictability. Assuming that chewing forces up to 600 N may occur in the molar region and loading of dental ceramics causes fatigue and weakening over time, the clinical application may not be recommended.
authors.affiliation: Zentrum für Zahnmedizin der Universität Basel Klinik für Prothetik und Kaufunktionslehre Hebelstr. 3, CH-4056 Basel. oliver.rodiger@unibas.ch
authors.forename: Oliver
authors.initials: O
authors.lastname: Rodiger
authors.forename: Heinrich F
authors.initials: HF
authors.lastname: Kappert
authors.forename: Carlo P
authors.initials: CP
authors.lastname: Marinello
mesh_terms: D001641:Bicuspid; D000044:Dental Abutments; D003776:Dental Porcelain; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D003779:Denture Design; D003830:Denture, Partial, Fixed; D006801:Humans; D008334:Mandible; D008422:Materials Testing; D016876:Metal Ceramic Alloys; D008963:Molar; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D014025:Titanium
chemical_list: D016876:Metal Ceramic Alloys; C077451:Procera; D003776:Dental Porcelain; D014025:Titanium