title: Load-bearing capacity of all-ceramic posterior inlay-retained fixed dental prostheses.
abstract: The purpose of this in vitro study was to compare the quasi-static load-bearing capacity of all-ceramic resin-bonded three-unit inlay-retained fixed dental prostheses (IRFDPs) made from computer-aided design/computer-aided manufacturing (CAD/CAM)-manufactured yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) frameworks with two different connector dimensions, with and without fatigue loading. Twelve IRFDPs each were made with connector dimensions 3 x 3 mm(2) (width x height) (control group) and 3 x 2 mm(2) (test group). Inlay-retained fixed dental prostheses were adhesively cemented on identical metal-models using composite resin cement. Subgroups of six specimens each were fatigued with maximal 1,200,000 loading cycles in a chewing simulator with a weight load of 25 kg and a load frequency of 1.5 Hz. The load-bearing capacity was tested in a universal testing machine for IRFDPs without fatigue loading and for IRFDPs that had not already fractured during fatigue loading. During fatigue testing one IRFDP (17%) of the test group failed. Under both loading conditions, IRFDPs of the control group exhibited statistically significantly higher load-bearing capacities than the test group. Fatigue loading reduced the load-bearing capacity in both groups. Considering the maximum chewing forces in the molar region, it seems possible to use zirconia ceramic as a core material for IRFDPs with a minimum connector dimension of 9 mm(2). A further reduction of the connector dimensions to 6 mm(2) results in a significant reduction of the load-bearing capacity.
authors: Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University of Kiel, Kiel, Germany. dpuschmann@proth.uni-kiel.de
authors: Djamila
authors: D
authors: Puschmann
authors: Stefan
authors: S
authors: Wolfart
authors: Klaus
authors: K
authors: Ludwig
authors: Matthias
authors: M
authors: Kern
mesh_terms: D001732:Bite Force; D002484:Cementation / Q000379:methods; D002516:Ceramics / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D017076:Computer-Aided Design; D000044:Dental Abutments; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D003779:Denture Design; D003781:Denture Retention; D016379:Denture, Partial, Fixed, Resin-Bonded; D006801:Humans; D007284:Inlays; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D019231:Tooth Preparation, Prosthodontic; D016474:Weight-Bearing; D015019:Yttrium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D003188:Composite Resins; D019279:Resin Cements; C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; D015019:Yttrium; D015040:Zirconium