الهام سينمبري

Amongst the advanced materials, glass ceramics have the most resemblance to the natural tooth, aesthetically, biologically, and structurally. It is the main reason for using these materials in the dental industry, especially for implant applications. In this study, Apatite Wollastonite Glass-Ceramic in CaO-MgO-SiO2 system was synthesized by the sintering method with and without adding zirconia. At first, initial batch turn into glass liquid in the furnace and then turned into frit by quenching. After that, the frit powder was pressed by hydraulic press and sintered by electrical furnace from 890 to 1000°C. Crystallization behavior, phase combination, and morphology of glass-ceramic were characterized. Physical properties including water absorption, bulk density, apparent density, and linear shrinkage of samples were investigated as criteria of sinterability to obtain the optimized sample. Afterward, bending strength, fracture toughness, microhardness, and brittle index were eva‎luated. The results indicated that the most crystallized phase in the Glass-Ceramic was Apatite Ca5(PO4)3(H-F) and the next phase which crystallized less was Wollastonite (CaSiO3). It has also revealed that the presence of tetragonal zirconia with an amount of 5%wt, added to the initial batch, can increase the porosity of the glass ceramics, which leads it to a significant improvement in machinability of the sample, compared to non-zirconia glass-ceramic. However, the bending strength, fracture toughness and microhardness of the sample containing zirconia were also affected by porosity and decreased, compared to the pure apatite wollastonite.

شيشه سراميك , آپاتيت ولاستونيت , ماشينكاري پذيري , زيركونيا , خواص مكانيكي

glass ceramic , Apatite wollastonite , machinability , zirconia , mechanical properties

Elham Sinambari

Dr. Eftekhari Yekta