调拌纸板厚度对玻璃离子水门汀抗压强度的影响

目的: 探讨调拌纸板厚度变化对玻璃离子水门汀抗压强度的影响。方法: 在相同的实验条件下,分别采用60、40、20、1张纸的纸板(P60、P40、P20、P1)对3种不同的玻璃离子水门汀进行调拌,在其凝固后进行抗压强度检测,并用扫描电镜观察不同组别材料断面气泡形成情况。结果: (1) 抗压强度：①ChemFil Superior玻璃离子材料(CF)：P1组平均抗压强度最高,与P40、P60组相比差异有统计学意义(P=0.041、0.032);②而至富士IX GP玻璃离子材料(IX)：P1组平均抗压强度最高,与P40、P60组相比差异有统计学意义(P=0.042、0.038);③Glaslonomer FX-Ⅱ玻璃离子材料(FX)：P1组平均抗压强度最高,与P20、P40、P60组相比差异有统计学意义(P=0.031、0.040、0.041),其余各组间差异无统计学意义,三种材料均显示出随着调拌纸板厚度的下降,玻璃离子抗压强度逐渐升高,纸板厚度与玻璃离子抗压强度成高度线性负相关,CF、IX、FX相关系数分别为-0.927、-0.989、-0.892。(2)扫描电镜下观察：三种材料均显示P1组气泡最少。结论: 采用1张纸的纸板调拌玻璃离子水门汀的气泡最少,并可以获得更高的抗压强度。

Influence of paper mixing pads thickness on the compressive strength of glass ionomer cement

Objective: To explore the influence of the thickness of mixed cardboard on the compressive strength of glass ionomer cement and the associated factors. Methods: Three different types of glass ionomer cements were mixed on the top of 60, 40, 20 and 1 pieces of paper (P60, P40, P20 and P1), respectively. The compressive strength of the materials was tested after solidification, and the bubble rate was calculated with the assistance of scanning electron microscope. Results: (1) Compressive strength: ① ChemFil Superior glass ionomer (CF): The average compressive strength of P1 group was the highest, which was significantly different from that of P40 and P60 groups (P values were 0.041 and 0.032 respectively); ② To Fuji IX GP glass ionomer (IX): The average compressive strength of P1 group was the highest, which was statistically different from that of P40 and P60 groups (P values were 0.042 and 0.038 respectively); ③ Glaslonomer FX-Ⅱ glass ionomer cement (FX): The average compressive strength of P1 group was the highest, which was statistically different from that of P20, P40 and P60 groups (P values were 0.031, 0.040 and 0.041 respectively), but there was no statistical difference among the other groups. All the three materials showed that the compressive strength of glass ions gradually increased with the decrease of the thickness of the blended paperboard, and the two materials had a highly linear negative correlation, the correlation coefficients of which were CF-0.927, IX-0.989, FX-0.892, respectively. (2) Scanning electron microscope: P1 group had the least bubbles among the three materials. Conclusion: It indicates that the thickness of mixed cardboard has a negative correlation with the compressive strength of glass ions. The thicker the mixed cardboard is, the greater the elasticity is. Excessive elasticity will accelerate the mixing speed when the grinding glass ions. Studies have shown that the faster the speed of artificial mixing is, the more bubbles is produced.The thicker ther mixed cardboard is, the more bubblesn are generated by glass ionomer cement, and the higher the compressive strength is. Using one piece of paper board to mix glass ionomer cement has the least bubbles and can obtain higher compressive strength.