Volume shrinkage mechanism of gutta-percha point studied by differential scanning calorimetry and volume dilatometer in vitro
Volume shrinkage mechanism of gutta-percha point studied by differential scanning calorimetry and volume dilatometer in vitro
复制标题
差示扫描量热法和体积膨胀仪体外研究古塔胶尖体积收缩机制
DOI：
10.1016/j.polymertesting.2018.10.006
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发表时间：
2019-02-01
期刊：
影响因子：
5.1
通讯作者：
Wang, Xiaoyan
中科院分区：
文献类型：
--
作者：
Dong, Mengjie;Zhang, Jichuan;Wang, Xiaoyan
从古塔胶（GP）的晶相转变和导热填料的热膨胀和收缩的角度探讨了古塔胶点体积收缩的机理。采用差示扫描量热法（DSC）通过测定晶型转变引起的热焓变化，间接计算GP点的体积收缩率（VSR）。用体积法直接测定VSR，验证DSC的结果。用DSC法计算的GP点的VSR约为2%，与直接用体积膨胀仪测定的结果一致。GP点的体积收缩由两个因素驱动，一个是GP的结晶相变，其贡献了GP点的VSR的约99%，另一个是导热填料的冷收缩，其贡献率仅为约1%，可以完全忽略。这对了解GP点材料的体积收缩行为，减少体积收缩对临床治疗的不良影响具有重要意义。
The mechanism of the volume shrinkage of gutta-percha (GP) point was investigated from the viewpoints of crystalline phase transition of GP and thermal expansion and contraction of thermal-conductive filler. Differential scanning calorimetry (DSC) was employed to calculate the volume shrinkage rate (VSR) of GP point indirectly by determining enthalpy changes that were caused by the crystalline phase transition. Volume dilatometer was utilized to determine the VSR directly to verify the result of DSC. The VSR of GP point calculated by DSC was approximately 2%, which was in good consistence with the result of volume dilatometer tested directly. The volume shrinkage of GP point was driven by two factors, one was the crystalline phase transition of GP that contributed to approximately 99% of the VSR of GP point, and the other was the cold contraction of thermal-conductive filler that could be ignored completely because its contribution rate was only approximately 1%. It was valuable to understand the volume shrinkage behavior of GP point materials and decrease the adverse effect of volume shrinkage in clinical therapy.