پرستو مبيني دهكردي

Dental Ceramica are commanl bioinert and biocompatible and are utilized as dental restorations. Among these materials, glass-ceramics have a great importance due to the easy of production, aesthetic aspects and superior properties including translucency, low thermal conductivity, high mechanical strength, chemical durability along with abrasion resistance and hardness similar to natural tooth. This project aims to highlight to role of aluminum oxide additive on sinterability, mechanical and chemical properties as well as the microstructure of fluorcanasite dental glass-ceramics. In this regard, the base glass and glasses containing three different amounts of aluminum oxide were obtained through melt quenching technique. Molten glasses were poured from silica crucible into water and transformed to frit. The obtained frits were pressed into discs and heat treated at temperature interval of 650-1000°C. In order to eva‎luate crystallization behavior and identify crystalline phases precipitated during heat treatment, different thermal analysis (DTA), X-ray diffractometry (XRD) and fieldemision scanning electron microscopy (FESEM) were accordingly used. To eva‎luate sinterability parameters, linear shrinkage, water absorption and bulk density of fabricated glass-ceramics were measured versus different heat treatment temperature and compared Structural eva‎luation of all starting glasses by Raman spectroscopy confirmed the role of aluminum ions as the glass network modifier. According to the measurement of sinterability parameters, 950°C was chosen as the optimized sintering temperature. Among the examined glass-ceramics, glass-ceramic Al6 (containing 6 weight ratio of aluminum oxide) showed the most flexible strength (147.6± 14.8 MPa) and fracture toughness (2.47 ± 0.19 MPa.m1/2) as well as the least chemical dissolution (2714µg/cm2). This specimen was chosen as the optimized glass-ceramic in the present work. On the basis of XRD patterns and FESEM observation, flourcanasite and calcium fluoride were identified in all examined glass-ceramics. Furthermore, leucite was also detected in both Al9 and Al12 glass-ceramics.

شيشه-سراميك , سراميك¬هاي دنداني , زينترپذيري , فلوركاناسيت , اكسيد آلومينيوم

: glass-ceramic , dental cerami , sinterability , fluorcanasite , aluminum oxide

parastoo mobini

dr bijan eftekhariyekta- dr sara banijamali