Reinforcement effect of short glass fibers with CaO- P(2)O(5) -SiO(2) -Al(2)O(3) glass on strength of glass-ionomer cement.
OBJECTIVE
A high strength glass-ionomer (not resin-modified) cement was developed using short fibers of CaO--P(2)O(5)--SiO(2)--Al(2)O(3) (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.


METHODS
The 40 mass% short fibers of CPSA glass were added to the powder of commercial glass-ionomer cement. Beam specimens of set cement (25 x 2 x 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 60s of dwell time at 4 and 60 degrees C for 2500, 5000, and 10,000 cycles. The other specimens were stored in water at 37 degrees 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.


CONCLUSIONS
These findings suggested that glass-ionomer cement reinforced with CPSA short fibers maintains a higher strength than the conventional cement after aging.
Kawano
F
F
Department of Removable Prosthodontics, University of Tokushima, School of Dentistry, 3-18-15 Kuramoto-Cho, Tokushima 770-8504, Japan. fumiaki@dent.tokushima-u.ac.jp
Kon
M
M
Kobayashi
M
M
Miyai
K
K
D000704:Analysis of Variance; D004548:Elasticity; D005898:Glass; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006358:Hot Temperature; D008422:Materials Testing; D018583:Pliability; D014867:Water / Q000737:chemistry
D005899:Glass Ionomer Cements; C417772:calcium oxide-diphosphorus pentoxide-silicon dioxide-aluminum oxide glass; D014867:Water