加热时间和温度对环氧树脂和硅酸钙基根管封闭剂的影响。

The Effect of Heating Time and Temperature on Epoxy Resin and Calcium Silicate-based Endodontic Sealers.

机构信息

Department of Restorative Dental Sciences, College of Dentistry, University of Dammam, Dammam, Kingdom of Saudi Arabia.

出版信息

J Endod. 2017 Dec;43(12):2112-2118. doi: 10.1016/j.joen.2017.08.008. Epub 2017 Oct 21.

DOI:10.1016/j.joen.2017.08.008

PMID:29033089

Abstract

INTRODUCTION

With the growing use of warm obturation techniques during endodontic treatment, more interest is directed toward sealers' compatibility with heat. This study aimed to evaluate the effect of heat application duration and temperature on epoxy resin- and calcium silicate-based sealers using chemical and thermogravimetric analyses.

METHODS

Freshly mixed samples (n = 5/group) of each sealer were heated at 200°C or 250°C for 30 or 60 seconds. Additional 2 sets of samples were examined directly after mixing or after setting without heat exposure. Raman spectroscopy was used to identify changes in the chemical structure, and a 2-way analysis of variance was performed to compare values of measurable peaks that exhibited changes. Additionally, Thermogravimetric Analysis (TGA) was used to evaluate the effect of heat on mass change where sealers were heated to 250°C at a rate of 20°C/min (11-minute duration) or maintained at 37°C for 8 hours.

RESULTS

No differences were detected among all the spectra of calcium silicate samples of different groups, while TGA revealed 15% and 18% weight loss upon heating at 250°C and 37°C, respectively. For the resin sealer, significant differences were detected when samples were heated for 60 seconds, involving bonds of benzene rings and aromatic amines in the uncured resin. TGA revealed minimal changes in the sealer mass (1.2% and 1.8%) on heating at 250°C and 37°C, respectively.

CONCLUSIONS

Heat application duration and temperature can affect the chemical structure of epoxy resin sealers. The consideration of endodontic sealer compatibility as well as the duration of heat application is essential when warm vertical obturation is used.

摘要

简介

随着根管治疗中温热封闭技术的应用越来越广泛，人们对密封剂与热的相容性的关注度也越来越高。本研究旨在通过化学和热重分析评估热应用时间和温度对基于环氧树脂和硅酸钙的密封剂的影响。

方法

将新鲜混合的各密封剂样本（每组 n=5）分别加热至 200°C 或 250°C，加热时间为 30 秒或 60 秒。另外两组样本直接在混合后或不进行热暴露的情况下凝固后进行检查。拉曼光谱用于鉴定化学结构的变化，采用双向方差分析比较表现出变化的可测量峰的数值。此外，热重分析（TGA）用于评估热对质量变化的影响，密封剂以 20°C/min 的速率加热至 250°C（持续 11 分钟）或在 37°C 下保持 8 小时。

结果

不同组的硅酸钙样本的所有光谱之间均未检测到差异，而 TGA 显示在 250°C 和 37°C 加热时分别损失 15%和 18%的重量。对于树脂密封剂，当加热 60 秒时，检测到明显的差异，涉及未固化树脂中苯环和芳香胺的键。TGA 显示在 250°C 和 37°C 加热时，密封剂质量的变化很小（分别为 1.2%和 1.8%）。