Evaluation of Marginal Fit and Fracture Resistance of Zirconia Implant Abutment Supporting Two Types of Metal Free CAD/ CAM Restorations

Purpose: To evaluate marginal fit as well as fracture resistance of zirconia implant abutment supporting two types of metal free CAD/CAM restorations. Materials and methods: Twenty ready-made ZrO2 abutments resembling lower first premolar
squeezed and stabled to its conforming titanium dummy implants were implanted in epoxy resin blocks. Samples were divided into two groups in relation to the material utilized for the fabrication of the copings; group (I) (n=10): zirconia copings, group (II) (n=10): breCAM.BioHPP copings. All copings were machined using CAD/CAM system. Samples were exposed to a fatigue procedure for 20,000 cycles. Marginal fit was determined using digital stereomicroscope. Fracture resistance was registered using universal testing machine. The samples were overloaded till last fracture occurred and load at fracture was documented. Analysis of data was examined using accessible software programme (SPSS 18). Results: BreCAM.BioHPP copings, group (II), registered a statistically significant higher mean vertical marginal gap value (122.08±25.05μm) in addition to higher mean failure load value (2828.47±735.4N) compared to zirconia copings, group (I) (27.06±3.2μm) (416.06±22.16N) respectively. Conclusions: Material type used for the fabrication of the copings influences marginal fit and fracture resistance. Zirconia coping samples showed higher marginal fit and
lower fracture resistance than breCAM.BioHPP coping samples.