Title: 1987 - Comparison of Mechanical Properties of Four Different CAD/CAM Blocks
Simge Canatan (Presenter)
Fatma Öz, Hacettepe University Faculty of Dentistry
Sukran Bolay, Hacettepe University Faculty of Dentistry
Objectives: The purpose of this in vitro study was to evaluate and compare the mechanical properties (flexural strength, young's modulus, vickers hardness) of different CAD/CAM blocs.
Methods: The materials tested in this study are two resin infiltrated ceramics (Lava Ultimate and Cerasmart), a feldspatic ceramic (Vita Mark II) and a lithium disilicate glass-ceramic (IPS e.max CAD). Flexural strength, young's modulus and vickers hardness properties were evaluated. Bar-shaped specimens (12×2×2 mm) (n=16) were prepared for flexural strength and young's modulus measurements. Specimens were submitted to a 3-point bend test using a universal testing machine at a cross-head speed of 0.5 mm/min. For vickers hardness tests, bar-shaped specimens (12×2×2 mm) were prepared (n=7) and surface hardness values were recorded using a microhardness tester. All data were statistically analyzed using Kruskall Wallis and Mann Whitney U test for multiple comparison (p=0.05).
Results: The mean flexural strength values of Lava Ultimate (152.06 ±21.92 MPa) and Cerasmart (144.13±33.67 MPa) blocks were significantly higher than Vita Mark II (99.05±27.89) and IPS e.max CAD (118.81±22.18) blocks (p<0.05). The young's modulus values ranged from 54.11±6.19 MPa (Vita Cerasmart) to 52.8 ±10.5 MPa (IPS e.max CAD). The mean Vickers hardness values ranged from 80.34 (Cerasmart) to 698.12 (IPS e.max CAD). Lava Ultimate (134.54) and Cerasmart (80.34) exhibited lower Vickers microhardness values than IPS e.max CAD (698.12) and Vita Mark II (644.11). Pearson correlation test showed significant correlation between flexural strength and young's modulus(p<0.05).
Conclusions: Although resin infiltrated ceramic blocks demonstrated higher flexural strength values, IPS e.max CAD and Vita Mark II showed higher young's modulus and Vickers microhardness values.
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE