Department of Periodontology and Operative Dentistry, Westphalian Wilhelms-University, Münster, Germany.
Private Office, Kieferchirurgie Gera, Gera, Germany.
Int Endod J. 2020 May;53(5):690-697. doi: 10.1111/iej.13267. Epub 2020 Feb 11.
To gain information in a laboratory setting about the effect of thermal treatment of epoxy resin-based and zinc oxide-eugenol-based sealers.
AH Plus and Pulp Canal Sealer (PCS) were exposed to thermal treatment at 37, 47, 57, 67, 77, 87 and 97 °C for 30 s. According to clinically relevant considerations, intracanal sealer temperature is likely not to exceed 60 °C during warm vertical root canal filling. Heat application is recommended for less than 30 s during continuous wave technique, but might exceed this threshold in complex cases. Furthermore, heat treatment at 97 °C was performed for 60 and 180 s to simulate inappropriate implementation of warm vertical filling techniques. Specimens were heated inside 2-mL plastic tubes in a thermo-controlled water bath until the temperatures were reached and kept at this temperature for the determined period of time. Afterwards, specimens were cooled to body temperature and physical properties (setting time, flow, film thickness according to ISO 6876) were assessed. Chemical properties (Fourier transformed infrared spectroscopy) were assessed after complete setting of the specimens in an incubator at 37 °C and 100% humidity. Statistical analysis of physical properties was performed using Kruskal-Wallis test (P = 0.05).
The setting time of AH Plus and PCS decreased when temperature and duration of heat application increased. Whilst the setting time of AH Plus decreased from 622 min at 20 °C (for 30 s) to 381 min at 97 °C (for 180 s; P < 0.05), heat treatment of PCS at 97 °C for 180 s led to an immediate setting of the material. From 20 °C (for 30 s) to 97 °C (for 30 s), the setting time of PCS decreased from 80.1 to 41.0 h (P < 0.05). Film thickness and flow were not relevantly influenced by thermal treatment except for PCS at 97 °C for 180 s. FT-IR spectroscopy did not reveal any chemical changes of either sealer after thermal treatment.
Thermal treatment simulating clinically relevant temperature levels and heating times did not lead to any substantial physical or chemical changes at all temperature levels when heating did not exceed 60 s. AH Plus and Pulp Canal Sealer can be considered suitable for warm root filling techniques.
在实验室环境中获取关于热治疗环氧树脂基和氧化锌丁香酚基封闭剂的效果的信息。
将 AH Plus 和牙髓腔封闭剂（PCS）暴露于 37、47、57、67、77、87 和 97°C 的热治疗中 30 秒。根据临床相关考虑，在温热垂直根管充填过程中，根管内封闭剂温度不太可能超过 60°C。连续波技术中推荐加热时间小于 30 秒，但在复杂情况下可能超过此阈值。此外，对 97°C 进行 60 和 180 秒的热处理以模拟温热垂直充填技术的不当实施。将样本在控温水浴中的 2-mL 塑料管内加热，直到达到并保持在该温度下的确定时间段。之后，将样本冷却至体温，并评估物理性能（凝固时间、流动度、根据 ISO 6876 测量的薄膜厚度）。在 37°C 和 100%湿度的孵育箱中完全凝固后，评估化学性能（傅里叶变换红外光谱）。使用 Kruskal-Wallis 检验（P=0.05）对物理性能进行统计分析。
随着温度和加热时间的增加，AH Plus 和 PCS 的凝固时间缩短。虽然 AH Plus 的凝固时间从 20°C（30 秒）时的 622 分钟降低至 97°C（180 秒）时的 381 分钟（P<0.05），但 PCS 在 97°C 下加热 180 秒会导致材料立即凝固。从 20°C（30 秒）到 97°C（30 秒），PCS 的凝固时间从 80.1 小时缩短至 41.0 小时（P<0.05）。除了 PCS 在 97°C 加热 180 秒外，热治疗对薄膜厚度和流动度没有明显影响。傅里叶变换红外光谱显示热治疗后两种封闭剂均未发生任何化学变化。
在加热时间不超过 60 秒的情况下，模拟临床相关温度水平和加热时间的热治疗不会导致任何实质性的物理或化学变化。AH Plus 和牙髓腔封闭剂可用于温热根充技术。
