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Fracture and Fatigue Resistance of Cemented versus Fused CAD‐on Veneers over Customized Zirconia Implant Abutments
Author(s) -
Nossair Shereen Ahmed,
Aboushelib Moustafa N.,
Morsi Tarek Salah
Publication year - 2015
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/jopr.12253
Subject(s) - veneer , materials science , cubic zirconia , dental porcelain , fractography , fracture (geology) , cad , composite material , universal testing machine , implant , dentistry , ceramic , ultimate tensile strength , engineering drawing , medicine , engineering , surgery
Purpose To evaluate the fracture mechanics of cemented versus fused CAD‐on veneers on customized zirconia implant abutments. Materials and Methods Forty‐five identical customized CAD/CAM zirconia implant abutments (0.5 mm thick) were prepared and seated on short titanium implant abutments (Ti base). A second scan was made to fabricate 45 CAD‐on veneers (IPS Empress CAD, A2). Fifteen CAD‐on veneers were cemented on the zirconia abutments (Panavia F2.0). Another 15 were fused to the zirconia abutments using low‐fusing glass, while manually layered veneers served as control (n = 15). The restorations were subjected to artificial aging (3.2 million cycles between 5 and 10 kg in a water bath at 37°C) before being axially loaded to failure. Fractured specimens were examined using scanning electron microscopy to detect fracture origin, location, and size of critical crack. Stress at failure was calculated using fractography principles (alpha = 0.05). Results Cemented CAD‐on restorations demonstrated significantly higher (F = 72, p < 0.001) fracture load compared to fused CAD‐on and manually layered restorations. Fractographic analysis of fractured specimens indicated that cemented CAD‐on veneers failed due to radial cracks originating from the veneer/resin interface. Branching of the critical crack was observed in the bulk of the veneer. Fused CAD‐on veneers demonstrated cohesive fracture originating at the thickest part of the veneer ceramic, while manually layered veneers failed due to interfacial fracture at the zirconia/veneer interface. Conclusions Within the limitations of this study, cemented CAD‐on veneers on customized zirconia implant abutments demonstrated higher fracture than fused and manually layered veneers.