Degree of Conversion of a Methacrylate-based Endodontic Sealer: A Micro-Raman Spectroscopic Study

Wu, Wan-Cui; Shrestha, Deepti; Wei, Xi; Ling, Jun-Qi; Zhang, Wei-Hong; Chen, Jian

doi:10.1016/j.joen.2009.10.015

« Previous Next »Journal of Endodontics
Volume 36, Issue 2 , Pages 329-333, February 2010

Degree of Conversion of a Methacrylate-based Endodontic Sealer: A Micro-Raman Spectroscopic Study

Wan-Cui Wu, MDS
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Department of Stomatology, Second Affiliated Hospital of Guangzhou Medical College, Guangzhou, Guangdong, China
Deepti Shrestha, MDS
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China
Xi Wei, MDS, PhD
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Address requests for reprints to Assoc. Prof. Xi Wei, Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou 510055, China.
Jun-Qi Ling, PhD
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China
Wei-Hong Zhang, BS
- Instrumentation Analysis and Research Center, Sun Yat-Sen University, Guangzhou, Guangdong, China
Jian Chen, PhD
- Instrumentation Analysis and Research Center, Sun Yat-Sen University, Guangzhou, Guangdong, China

published online 16 December 2009.

Abstract

Introduction

Recently, a methacrylate-based obturation system, Resilon/RealSeal SE, has been developed to replace gutta-percha and traditional sealers. As a resin-based material, degree of conversion (DC) is one of the most important characteristics. The aim of this study was to investigate the time-dependent change of DC of RealSeal SE as well as the influence of canal moisture and root canal depth on it.

Methods

DC of RealSeal SE, either self-cured or dual-cured (n = 8 in each group), was calculated according to the Raman spectra obtained at different times after mixing. Thirty extracted teeth with single canal were instrumented and divided randomly into 2 groups in terms of different canal drying methods. In the ethanol group, excess distilled water in root canal was removed with paper points followed by 95% ethanol. In the paper points group, root canals were blot-dried with paper points until the last one appeared dry. DC of RealSeal SE was calculated from serial cross sections (2, 5, and 8 mm from the apex) obtained 1 week after obturation with Resilon/RealSeal SE.

Results

Significant increase in DC of RealSeal SE was observed in 1 week (P < .01), with little change afterwards (P > .05). DC of sealer in ethanol group was significantly higher than in paper points group (P < .01). However, DCs of RealSeal SE at different levels of tooth sections were not significantly different (P > .05).

Conclusions

Both self-cured and dual-cured RealSeal SE achieved stable DC after 1 week. Root canal moisture was a critical factor in determining DC of RealSeal SE.

Key Words: Degree of conversion, micro-Raman spectroscopy, Resilon/RealSeal SE, root canal moisture