Radiopacity and microhardness changes and effect of X-ray operating voltage in resin-based materials before and after the expiration date
Radiopacity and microhardness changes and effect of X-ray operating voltage in resin-based materials before and after the expiration date
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树脂基材料有效期前后X射线不透性和显微硬度的变化及X射线工作电压的影响
DOI：
10.1590/s1516-14392004000300006
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
O. Zaniquelli
中科院分区：
文献类型：
--
作者：
C. Tirapelli;Fernanda de Carvalho Panzeri;H. Panzeri;L. C. Pardini;O. Zaniquelli
本研究观察到与未过期材料相比，过期树脂基材料的射线不透性和显微硬度以及所用X射线源的操作特性发生变化。为每种材料制备五个2 mm厚的固化试样：复合树脂（P60®、Z100®）和复合物（Dyract AP®）。使用透射密度计比较树脂基材料的密度与99.5%纯铝阶梯楔的等效（mm）密度，评价试样的不透射线性。表面显微硬度测量进行了使用校准的维氏压头上的三个不同点的相同的表面。ANOVA和Tukey检验（预设α = 0.05）显示，过期材料的不透射线性无显著变化。一种材料（Filtek P60）表现出较低的不透射线性和较低的KVp。Z100的显微硬度变化具有统计学显著性：对于该材料，失效后的显微硬度显著低于失效日期前。
This study observed alteration in the radiopacity and microhardness of expired resin-based materials compared to non-expired materials and the operating characteristics of the X-ray source used. Five 2 mm-thick cured specimens were prepared for each material: composite resins (P60®, Z100®), and a compomer (Dyract AP®). Radiopacity of the specimens was evaluated comparing the density of the resin-based material to an equivalent (mm) density of a 99.5% pure aluminum step wedge using a transmission densitometer. Surface microhardness measurements were carried out using a calibrated Vickers indenter on three different points of the same surface. ANOVA and Tukey tests (pre-set alpha = 0.05) revealed that expired materials showed no significant change in radiopacity. One material (Filtek P60) demonstrated lower radiopacity with lower KVp. Change in microhardness wa s statistically significant for Z100: for this material, the microhardness after expiration was significantly lower than before the expiration date.