Basic Research| Volume 36, ISSUE 2, P329-333, February 2010

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

Published:December 16, 2009DOI:



      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.


      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.


      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).


      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.

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