Preparation of calcium fluoroaluminosilicate glasses containing sodium and phosphorus by the nonhydrolytic sol-gel method

摘要

Aluminum and silicon oxide-based inorganic matrices have been extensively studied because of their countless applications. Dental cements consist of aluminum and silicon-based amorphous polymeric materials containing fluoride, sodium, phosphorus and calcium, which are also good candidates for bone replacement. The nonhydrolytic sol-gel method has emerged as an alternative route for the preparation of these materials under milder conditions than those employed in traditional methods, such as oxide fusion. The main advantages of the nonhydrolytic sol-gel method include the use of low temperatures and the ready availability and easy purification of the precursors. Together, these factors have contributed to the production of highly pure materials with controlled porosity and nanometric particles. Dental restorations based on aluminosilicate matrices are known as glass ionomer cements. These materials have interesting physical and dental properties, mainly because they display anticariogenic activity and exhibit prolonged adhesiveness to the dental structure. The base of the ionomer is an aluminosilicate that is industrially synthesized by the fusion of SiO_2, Al_2O_3, AlF_3, CaF_2, NaF and AlPO_4, in various concentrations. The characterizations conducted in this study reveal that this ionomer displays interesting properties, so its use as a precursor of dental cement and a biomaterial for bone replacement is highly recommended.