Preparation of Al-free glass-ionomer cement

Glass-ionomer cements have been widely used in dentistry. Basically they consist of CaO-Al2O3-SiO2-CaF2 glass powders and polyacrylic acid. The glass-ionomer cement does not show bioactivity, i.e., bone-bonding ability. One of the reasons for this non-bioactivity may be attributed to the presence of aluminum in the glass powders which suppresses the apatite formation in the living body. In the present study, preparation of an Al-free glass-ionomer cement was attempted by using CaO-Fe2O3-SiO2 glass powders. The obtained cement showed an appropriate workability and setting behavior. The cementation was speculated to progress via the release of Fe3+ and Ca2+ ions from the glass to form Fe(III) and Ca(II) polyacrylates.