Mechanical and Chemical Properties of Zr and P‐Doped Lithium Disilicate Glass Ceramics in Dental Restorations

The Weibull modulus, flexural strength, fracture toughness, Vickers microhardness, and chemical durability of sintered Li 2 O–SiO 2 glass ceramic specimens doped with P 2 O 5 or ZrO 2 were evaluated in accordance with the norm of EN ISO 6872. Peak crystallization temperatures, crystalline phases, and microstructure were characterized by means of differential thermal analysis, X‐ray diffraction, and scanning electron microscopy methods, respectively. Phase formation induced by the addition of P 2 O 5 led to precipitation of Li 3 PO 4 , which in turn caused more intensive crystallization of Li 2 SiO 3 . The high‐temperature crystalline phase Li 2 Si 2 O 5 was precipitated more intensively in P 2 O 5 containing specimens resulting in an interlocked microstructure of needle like disilicate crystals. Therefore, the P‐doped glass ceramic exhibited the optimum mechanical and chemical properties (i.e., m =15, σ f =181 ± 15 MPa, K I C =1.94 ± 0.19 MPa m 1/2 , H v =3.7 ± 1.1 GPa, chemical solubility=53 ± 9 μg/cm 2 )

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