水对3种双固化复合树脂冠核材料弯曲性能的影响

Effect of water storage on the flexural properties of three dual-cure core buildup composite resins

背景:口腔湿热环境会对牙科核材料的力学性能产生影响。目的:观察水对3种双固化复合树脂冠核材料质量变化率及弯曲性能的影响。方法:将LuxaCore Smartmix Dual、Para core和Clearfil DC Core三种牌号双固化复合树脂材料制成25 mm×2 mm×2 mm标准试件,于(37±1)℃的蒸馏水中保存0 d、1 d、1周、2周、3周和1个月后称质量,计算其质量变化率,并在万能试验机上测试三点弯曲性能。结果与结论:3种复合树脂的质量变化率均随着浸泡时间的增加而增加;对于相同浸泡时间下,3种树脂的质量变化率由大到小排列次序为:LuxaCore Smartmix Dual>ParaCore>Clearfil DC Core。LuxaCore Smartmix Dual树脂强度随浸泡时间的增加而降低;ParaCore树脂强度在浸泡3周内变化不显著(P>0.05),浸泡时间1个月时强度显著降低(P<0.05);Clearfil DC Core树脂强度在整个浸泡过程中没有显著性差异(P>0.05)。LuxaCore Smartmix Dual树脂模量在整个浸泡时间内呈现出下降趋势,但在最初2周的浸泡时间内无明显变化(P>0.05),当浸泡时间达到3周和1个月时模量显著降低(P<0.05);与浸泡前比,ParaCore和Clearfil DC Core两种复合树脂的模量值均下降,但这种变化不显著(P>0.05);3种复合树脂的弯曲性能随着质量变化率的升高而呈现出波动式下降的趋势。综合显示在3种树脂中,Clearfil DC Core的耐水性最佳。

BACKGROUND：Hydrothermal condition of oral environment has an effect on the mechanical properties of dental core materials. OBJECTIVE：To evaluate effect of water storage on the weight change rates and flexural properties of three dual-cure core buildup composite resins. METHODS： Rectangular specimens （25 mm×2 mm×2 mm） were prepared from three dual-cure core buildup composite resins （LuxaCore Smartmix Dual, Para core and Clearfil DC Core）. Specimens were stored in distiled water at 37℃ for 0, 1 day, 1, 2, 3 weeks and 1 month, respectively, weighted and then subjected to three-point bending test in a universal testing machine. RESULTS AND CONCLUSION： Weight change rates of the three composite resins increased with immersion time; at the same immersion time, weight change rates of three composite resins ranked as the folowing order： LuxaCore Smartmix Dual 〉 ParaCore 〉 Clearfil DC Core. The flexural strength of LuxaCore Smartmix Dual decreased with immersion time. The flexural strength of ParaCore showed no significant change during 3 weeks immersion （P 〉 0.05）, while it showed a significant decreasing after 1 month immersion （P 0.05）. The flexural modulus of LuxaCore Smartmix Dual showed a decreased trend in the whole immersion process, but it showed that there was no significant change during the first 2 weeks（P 〉 0.05）, while a significant decrease＆nbsp;occurred after 3 weeks and 1 month （P 0.05）; the flexural properties of three composite resins showed a fluctuant decreased trend along with weight changes increased. To sum up, Clearfil DC Core showed the best water resistance among three composite resins.