Mechanical properties of an improved visible light-cured resin-modified glass ionomer cement

This study investigates the mechanical properties (hardness, flexural stren gth and compressive strength) of a new light-cured resin-modified glass ion omer cement (Fuji II LC Improved). Effects of the increased powder:liquid r atio on mechanical properties and the correlation between different mechani cal properties were also studied. Mechanical properties of the cement at ma nufacturer's recommended powder:liquid ratio (F), 2% (F2) and 4% (F4) incre ased powder weight were measured after one day, one week and one month stor age in distilled water at 37 degreesC, Hardness testing (KHN; n=5) was done with a digital microhardness tester (load=500g, dwell time=15 seconds). Fl exural and compressive strength testing (MPa; n=5) were conducted based on ISO 4049 and BS6039, respectively, Results were analyzed using ANOVA/Scheff e's test (p <0.05) and Pearson's correlation (p <0.01), The maximum mechani cal properties of Fuji II LC Improved were achieved at one week, The hardne ss, flexural and compressive strength at one week was significantly higher than at one day. A decrease in all mechanical properties was observed at on e month. Mechanical properties were significantly affected by increased pow der: liquid ratio. After one month steerage, significance was as follows: H ardness-F, F2 > F4; Flexural strength-F4 >F, F2 and F > F2; Compressive str ength-F, F2 > F4 and F2 >F, A significant very strong and negative correlat ion was observed between flexural and compressive strengths (r=-0.97).