title: Clinical fit of four-unit zirconia posterior fixed dental prostheses.
abstract: The objective of this clinical study was to assess the internal and marginal accuracy of computer-aided design/computer-aided manufacturing (CAD/CAM)-generated four-unit all-ceramic posterior fixed dental prostheses (FDPs). The data were compared with the results of three-unit metal-ceramic and all-ceramic FDPs that were obtained in a previous study. Twenty-four patients were provided with all-ceramic posterior four-unit FDPs made from semisintered blank zirconia material. Prior to definitive insertion the accuracy was evaluated using a replica technique with a light body silicone that was stabilized with a heavy body material. The replica samples were examined using microscopy. The median marginal gap of the 24 four-unit FDPs was 77 mum. The median gap widths were 87 mum at the midaxial wall, 167 mum at the axio-occlusal transition of the abutments, and 170 mum at centro-occlusal location. Although the marginal accuracy of the four-unit FDPs differed significantly from that of the three-unit metal-ceramic FDPs (median 54 mum), the values obtained were clinically satisfactory and showed that semisintered zirconia blanks could be used for the fabrication of four-unit FDPs.
authors.affiliation: University of Leipzig, Department of Prosthodontics and Material Sciences, Leipzig, Germany. sven.reich@medizin.uni-leipzig.de
authors.forename: Sven
authors.initials: S
authors.lastname: Reich
authors.forename: Karsten
authors.initials: K
authors.lastname: Kappe
authors.forename: Hubertus
authors.initials: H
authors.lastname: Teschner
authors.forename: Johannes
authors.initials: J
authors.lastname: Schmitt
mesh_terms: D017076:Computer-Aided Design; D003776:Dental Porcelain; D003779:Denture Design / Q000295:instrumentation* / Q000379:methods; D003830:Denture, Partial, Fixed; D006801:Humans; D016876:Metal Ceramic Alloys; D003765:Models, Dental; D017755:Prosthesis Fitting; D016628:Replica Techniques; D015203:Reproducibility of Results; D015040:Zirconium
chemical_list: D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide