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Post space preparation timing of root canals sealed with AH Plus sealer
Hae-Ri Kim1, Young Kyung Kim2, Tae-Yub Kwon3
1Department of Dental Science, Graduate School, Kyungpook National University, Daegu, Korea.
Objectives:
To determine the optimal timing for post space preparation of root canals sealed with epoxy resin-based AH Plus sealer in terms of its polymerization and influence on apical leakage.
Materials And Methods:
The epoxy polymerization of AH Plus (Dentsply DeTrey) as a function of time after mixing (8, 24, and 72 hours, and 1 week) was evaluated using Fourier transform infrared (FTIR) spectroscopy and microhardness measurements. The change in the glass transition temperature (T ) of the material with time was also investigated using differential scanning calorimetry (DSC). Fifty extracted human single-rooted premolars were filled with gutta-percha and AH Plus, and randomly separated into five groups (n = 10) based on post space preparation timing (immediately after root canal obturation and 8, 24, and 72 hours, and 1 week after root canal obturation). The extent of apical leakage (mm) of the five groups was compared using a dye leakage test. Each dataset was statistically analyzed by one-way analysis of variance and Tukey's post hoc test (α = 0.05).
Results:
Continuous epoxy polymerization of the material with time was observed. Although the T values of the material gradually increased with time, the specimens presented no clear T value at 1 week after mixing. When the post space was prepared 1 week after root canal obturation, the leakage was significantly higher than in the other groups (p < 0.05), among which there was no significant difference in leakage.
Conclusions:
Poor apical seal was detected when post space preparation was delayed until 1 week after root canal obturation.
