Mitra S B, Kedrowski B L
3M Dental Products Division, St. Paul, MN 55144-1000, USA.
Dent Mater. 1994 Mar;10(2):78-82. doi: 10.1016/0109-5641(94)90044-2.
Several methacrylate/glass ionomer hybrid materials are now available for clinical use as restorative filling materials. However, the long-term resistance of these materials to physical degradation in the humid oral condition is not known. The objective of this investigation was to determine the mechanical properties, e.g., ultimate compressive strength and diametral tensile strength, of several glass ionomer materials as a function of time after aging in water at oral temperature.
Eight glass ionomer filling materials indicated for restorative or core build-up applications were studied. Three conventional glass ionomers, two metal-containing conventional glass ionomers and three methacrylate-modified systems were included in the study. Cured specimens of each were aged in distilled water at 37 degrees C for 24 h, 1 wk, 4 wk, 12 wk, 24 wk and 52 wk.
Like the conventional glass ionomers, the methacrylate-modified glass ionomers of this study, with one exception, did not exhibit a decrease in compressive strength, modulus and diametral tensile strength as a result of prolonged storage in water at oral temperature. Some differences among the various groups were apparent. The compressive strengths of the conventional glass ionomers were lower than the methacrylate-modified system, except for one material, Fuji II (GC Dental Corp.), of the former group. A significant difference in the compressive strength was seen between the encapsulated and hand-mixed versions of the same commercial brand product. The compressive modulus was higher and the diametral tensile strength was lower for the conventional systems indicating that, as a group, these materials are more brittle than the methacrylate-modified hybrid ionomers. With the exception of VariGlass VLC (L.D. Caulk), most of the materials studied showed little decrease in mechanical properties after aging in water for 52 wk.
These materials could, therefore, be indicated for use in applications where they are in contact with oral fluids under physiological conditions.
目前有几种甲基丙烯酸酯/玻璃离子水门汀混合材料作为修复性填充材料可供临床使用。然而，这些材料在口腔潮湿环境中对物理降解的长期耐受性尚不清楚。本研究的目的是确定几种玻璃离子水门汀材料在口腔温度的水中老化后的力学性能，如极限抗压强度和径向拉伸强度随时间的变化。
研究了八种用于修复或核修复的玻璃离子水门汀填充材料。研究包括三种传统玻璃离子水门汀、两种含金属的传统玻璃离子水门汀和三种甲基丙烯酸酯改性体系。每种材料的固化试件在37℃蒸馏水中老化24小时、1周、4周、12周、24周和52周。
与传统玻璃离子水门汀一样，本研究中的甲基丙烯酸酯改性玻璃离子水门汀，除一种外，在口腔温度的水中长时间储存后，抗压强度、模量和径向拉伸强度均未降低。不同组之间存在一些明显差异。传统玻璃离子水门汀的抗压强度低于甲基丙烯酸酯改性体系，但前一组中的一种材料富士II（GC牙科公司）除外。同一商业品牌产品的封装版和手工混合版之间的抗压强度存在显著差异。传统体系的压缩模量较高，径向拉伸强度较低，表明作为一个整体，这些材料比甲基丙烯酸酯改性混合离子水门汀更脆。除VariGlass VLC（L.D. Caulk）外，大多数研究材料在水中老化52周后的力学性能几乎没有下降。
因此，这些材料可用于在生理条件下与口腔液体接触的应用中。
