Reinforcement effect of short glass fibers with CaO–P2O5–SiO2–Al2O3 glass on strength of glass-ionomer cement

Objectives: A high strength glass-ionomer (not resin-modified) cement was developed using short fibers of CaO–P2O5–SiO2–Al2O3 (CPSA) glass. The purpose of this study was to clarify the effect of the CPSA short fibers contained in the flexural strength of the glass-ionomer cement. Method: The 40 mass% short fibers of CPSA glass were added to the powder of commercial glass-ionomer cement. Beam specimens of set cement (25×2×2 mm) were prepared for measuring the flexural strength (FS). The specimens of set commercial glass-ionomer cement (GI) were used for comparison with glass ionomer cement with CPSA (FRGI). Half of all specimens were thermocycled in water for 60 s of dwell time at 4 and 60°C for 2500, 5000, and 10,000 cycles. The other specimens were stored in water at 37°C as a control. The measurements were statistically analyzed using ANOVA. Results: The initial FS of FRGI was 18.1 and that of GI was 7.7 MPa. After thermocycling, the mean FS ranged from 19.3 to 26.3 MPa and 9.8 to 11.1 MPa for FRGI and GI, respectively. After storage in water, the mean FS of FRGI and GI ranged from 20.4 to 25.9 MPa and 9.4 to 10.1 MPa, respectively. Conclusion: These findings suggested that glass-ionomer cement reinforced with CPSA short fibers maintains a higher strength than the conventional cement after aging.