Strengthening of glass-ionomer cement by compounding short fibres with CaO-P2O5-SiO2-Al2O3 glass

The purpose of this study was to determine if short fibres of CaO-P-2 O-5-S iO2-Al2O3 (CPSA) glass possessing a particular aspect ratio (length/diamete r) could be used as a reinforcing agent for glass-ionomer cement. The powde r of a commercial glass-ionomer cement (not resin modified) was mixed with variously sized CPSA glass short fibres before mixing with the liquid of th e glass-ionomer cement. The mixed powders containing 60 mass% CPSA glass sh ort fibres (diameter, 9.7 +/- 2.1 mu m, aspect ratio, 5.0 +/- 0.9) obtained maximum values of 18 and 35 MPa for the diametral tensile strength (DTS) a nd flexural strength (FS) of set cements, respectively, after 24 h. These D TS and FS values were 1.8 and 4.5 times larger, respectively, than those of the set glass-ionomer cement not containing short fibres. Moreover, it was found that the addition of CPSA glass short fibres was remarkably more eff ective in the strengthening than electric glass (a typical glass fibre) sho rt fibres. The results suggested that the CPSA glass short fibres acted as a reinforcing agent for strengthening the glass-ionomer cement, because of the shape of short fibres and reactivity between the mixing liquid and shor t fibres. (C) 2000 Elsevier Science Ltd. All rights reserved.