Cerium oxide containing canasite based glass-ceramics for dental applications: Crystallization behavior, mechanical and chemical properties

The present work aims to investigate the role of CeO 2 (cerium oxide) on crystallization behavior, microstructural features as well as mechanical and chemical properties of canasite glass-ceramics for dental applications. The obtained results confirm that further addition of cerium oxide to the glass composition leads to a slight increase of crystallization temperatures and significant decrease of thermal expansion coefficients of the starting glasses. According to the Raman spectroscopy results, cerium ions increase the network connectivity of the parent glasses by increasing the number of bridging oxygens. During the two step heat treatment, the presence of cerium oxide favors crystallization of miserite (K(Ca,Ce) 5 Si 8 O 22 [(OH)F] 2 ) besides calcium fluoride (CaF 2 ) and canasite (Ca 5 Na 4 K 2 Si 12 O 30 F 4 ) crystalline phases. Based on the microstructural observations, canasite crystals have the inter-locked blade-like morphology whereas crystals of miserite have the cubic like morphology. Among the studied glass-ceramics, Base-C2 showed the highest value of chemical durability as well as acceptable mechanical properties fulfilling the essential requirements as a restorative dental material.