Effect of Connector Design on Fracture Resistance in Zirconia-based Fixed Partial Dentures for Upper Anterior Region.
The purpose of this study was to investigate the influence of the cross-sectional form and area of the connector on fracture resistance in three-unit zirconia fixed partial denture (FPD) frameworks for the upper anterior region. Sixty FPD framework specimens were fabricated using the CAD/CAM system. The cross-sectional form (Type I, II, or III) and area (9.0, 7.0, 5.0, or 3.0 mm(2)) of the connectors differed. The specimens were fixed to a jig capable of applying a load axially to the abutment teeth at an angle of 135 degrees. Each specimen was subjected to fracture load measurements using a universal testing machine and cross-sectional microscopic examination. Fracture load fell significantly with a decrease in cross-sectional area (p <0.01). In terms of cross-sectional form, an isosceles triangle with a gingival base yielded the highest fracture load. These results suggest that the connector of a three-unit zirconia-based FPD framework for the upper anterior region should be triangular, have a gingival base, sufficient height in the loading direction, and a cross-sectional area of >5.0 mm(2).
Department of Fixed Prosthodontics, Tokyo Dental College.
Yasushi
Y
Ogino
Syuntaro
S
Nomoto
Toru
T
Sato
D044466:Asian People; D017076:Computer-Aided Design; D000044:Dental Abutments; D003764:Dental Materials / Q000737:chemistry*; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis / Q000379:methods*; D003779:Denture Design / Q000379:methods* / Q000592:standards*; D003830:Denture, Partial, Fixed / Q000592:standards; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D013314:Stress, Mechanical; D015019:Yttrium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
D003764:Dental Materials; C499362:yttria stabilized tetragonal zirconia; D015019:Yttrium; D015040:Zirconium