Properties of heat-treated composites after aging in water
Properties of heat-treated composites after aging in water
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DOI：
10.1016/0109-5641(95)80034-4
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发表时间：
1995-09-01
期刊：
影响因子：
5
通讯作者：
Condon, JR
中科院分区：
文献类型：
--
作者：
Ferracane, JL;Hopkin, JK;Condon, JR
目标。固化后的热处理可以提高复合材料的断裂韧性和弹性模数。本研究的目的是确定复合材料在水中老化后的剩余增加量。在37℃水中老化1、7、30、60和180d后，测试了4种实验材料和1种商用复合材料(Z-100、3M牙科产品)的断裂韧性(K-lc)、弯曲弹性模量和弯曲强度。用双GMA/TEGDMA树脂制备了四种实验复合材料，并对其进行了表征。Micro=38vol%硅烷处理的二氧化硅，Fine=65vol%硅烷处理的1-2微米平均粒度的石英，混合=65vol%硅烷处理的1-2微米平均粒度和8微米平均粒度的石英，以及大=65体积%的8微米平均粒度的石英(其中只有75%是硅烷处理的)。所有标本均为光固化标本(正常治愈；三联体II-80 S)。每种复合材料的一组在120℃下进一步热固化10分钟(热固化)。第三组杂交体在前3分钟内同时受光照射(Elipar，Espe)进行热固化。到30d时，常温和热固化试件的断裂韧性(Avg)显著降低(ANOVA/Tukey‘s检验，p小于或等于0.05)。分别为16%和22%)，弯曲弹性系数(Avg.11%和11%)和抗折强度(Avg.25%和29%)。进一步的老化几乎没有影响。在加热过程中使用附加光固化对性能的影响并不比单独热固化对性能的影响更大。通过热处理产生的复合材料的一些性能的改善只是短期的好处，大部分是由于复合材料与水平衡时树脂基质的改变而被否定的。
Objectives. Post-cure heat treatments have been shown to increase the fracture toughness and elastic modulus of composites. The objective of this study was to determine ii the increase remained after the composites were aged in water.Methods. The fracture toughness (K-lc), flexural modulus and flexural strength of four experimental and one commercial composite (Z-100, 3M Dental Products) were tested alter 1, 7, 30, 60 and 180 d of aging in 37 degrees C water. The four experimental composites were made with a BisGMA/TEGDMA resin and were characterized as follows. Micro = 38 vol% silane-treated silica, Fine = 65 vol% silane-treated quartz of 1-2 mu m average size, Hybrid = 65 vol% silane treated quartz of a mixture of 1-2 mu m average and 8 mu m average size, and Large = 65 vol% quartz of 8 mu m average size (of which only 75% were silane-treated). All specimens were light-cured (normal-cured;Triad II - 80 s). One set of each composite was further heat-cured at 120 degrees C for 10 min (heat-cured). A third set of the Hybrid was heat-cured with simultaneous light exposure (Elipar, Espe) for the first 3 min.Results. By 30 d, normal-cured and heat-cured specimens showed significant (ANOVA/Tukey's test; p less than or equal to 0.05) reductions in fracture toughness (avg. 16% and 22%, respectively), flexural modulus (avg. 11% and 11%, respectively) and flexural strength (avg. 25% and 29%, respectively). Further aging had little effect. The use of additional light-curing during heating did not affect the properties more than heat-curing alone.Significance. The improvements in some of the properties of composites produced by heat-treating are of only short-term benefit, and are for the most part negated due to an alteration of the resin matrix as the composite equilibrates with water.