Graduate Dental Research, 81 Dental Squadron, 606 Fisher Street, Keesler Air Force Base, Biloxi, MS, 39534, USA.
Advanced Education in Endodontics, 81 Dental Squadron, Keesler Air Force Base, Biloxi, MS, USA.
Clin Oral Investig. 2017 Nov;21(8):2589-2602. doi: 10.1007/s00784-017-2059-5. Epub 2017 Feb 10.
The purpose of this study was to evaluate the thermal stability of 23 commercially-available endodontic obturation materials.
Specimens (n = 10) were sealed in aluminum differential scanning calorimetry (DSC) crucibles and subjected to thermal scan series consisting of a 25 to 70 °C at 5 °C/min followed by a rapid increase to 230 °C, followed by a second scan from 25 to 70 °C at 5 °C/min. The first scan evaluated the materials as-received followed by a worse-case-scenario thermal challenge simulating temperatures involved with warm vertical condensation obturation techniques. The second thermal scan observed any phase changes from the high temperature challenge. This two-scan process was repeated twice to observe changes encountered by repeat high heat exposure during obturation. Mean thermal enthalpies were analyzed with Kruskal-Wallis and Games-Howell post-hoc test. (p = 0.05).
Thermal behavior was material dependent. During the first thermal scan, materials typically demonstrated broad endothermic enthalpy curves suggesting either a gutta-percha phase mixture and/or an alpha crystalline phase. The first high-heat challenge produced definitive alpha/beta thermal phase signatures usually associated with gutta-percha. Changes in beta-phase enthalpies were noted with Therarmafil Plus and UltraFil Firmset while increase in alpha-phases was observed with GuttaCore, K3, Lexicon, and Schein Accessory Points.
Commercial endodontic gutta-percha obturation materials displayed thermal characteristics that were material dependent. However, all demonstrated stability at temperatures in excess to that experienced during warm vertical condensation techniques.
The gutta-percha obturation materials evaluated in this evaluation can be used successfully in warm vertical condensation techniques without fear of degradation.
本研究旨在评估 23 种市售根管充填材料的热稳定性。
将样本（n=10）密封在铝质差示扫描量热法（DSC）坩埚中，并进行热扫描系列，包括 25 至 70°C 的 5°C/min 升温，然后快速升温至 230°C，随后以 5°C/min 的速度进行第二次从 25 至 70°C 的扫描。第一次扫描评估了收到的材料，然后模拟了与热垂直加压技术相关的温度的最坏情况热挑战。第二次热扫描观察了高温挑战后的任何相变。重复两次该两扫描过程，以观察在根管充填过程中反复高温暴露所遇到的变化。用 Kruskal-Wallis 和 Games-Howell 事后检验分析平均热焓。（p=0.05）。
热行为取决于材料。在第一次热扫描中，材料通常表现出宽的吸热焓曲线，这表明存在一种牙胶相混合物和/或α晶相。第一次高温挑战产生了通常与牙胶相关的明确的α/β热相特征。Therarmafil Plus 和 UltraFil Firmset 中观察到β相焓的变化，而 GuttaCore、K3、Lexicon 和 Schein Accessory Points 中观察到α相的增加。
商业根管牙胶充填材料表现出与材料相关的热特性。然而，所有材料在高于热垂直加压技术所经历的温度下都表现出稳定性。
在这项评估中评估的牙胶充填材料可以在热垂直加压技术中成功使用，而不必担心降解。
