title: Effect of connector design on fracture resistance in all-ceramic fixed partial dentures for mandibular incisor region.
abstract: Yttrium tetragonal zirconia polycrystal frameworks were prepared for all-ceramic fixed partial dentures (FPDs) for the mandibular incisor region. The effects of the cross-sectional area and morphology of the connector on its strength were evaluated by fracture tests. Nine types of zirconia framework for a 3-unit FPD for a defect of 1 mandibular central incisor were prepared, each differing in cross-sectional area and morphology. Fracture tests were performed by loading until fracture using a universal testing machine. Fracture load was determined and fracture site examined. Significant differences were observed in fracture load according to the morphology and cross-sectional area of the connector (p<0.05, p<0.01, p<0.001). Fracture load differed significantly among all groups according to cross-sectional area, and was also greater when the shape of the connector formed an isosceles triangle widest at the base and the connector had the same height and width. These values still far exceeded 311 N, however, which is the average occlusal force in the incisor region. The results of this study suggest that connector design affects fracture load.
authors.affiliation: Department of Crown and Bridge Prosthodontics, Tokyo Dental College.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Murase
authors.forename: Syuntaro
authors.initials: S
authors.lastname: Nomoto
authors.forename: Toru
authors.initials: T
authors.lastname: Sato
authors.forename: Akimasa
authors.initials: A
authors.lastname: Shinya
authors.forename: Teruyoshi
authors.initials: T
authors.lastname: Koshihara
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Yasuda
mesh_terms: D001732:Bite Force; D002484:Cementation / Q000379:methods; D003442:Crowns; D000044:Dental Abutments; D003764:Dental Materials / Q000737:chemistry*; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis / Q000295:instrumentation; D003779:Denture Design; D003830:Denture, Partial, Fixed; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D007180:Incisor; D007576:Jaw, Edentulous, Partially / Q000534:rehabilitation*; D008334:Mandible / Q000473:pathology*; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry; D015019:Yttrium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003764:Dental Materials; D005899:Glass Ionomer Cements; C499362:yttria stabilized tetragonal zirconia; D014867:Water; D015019:Yttrium; D015040:Zirconium