Studying the Effect of Four Postspace Preparation Techniques on the Apical Seal Integrity of the Root Canals Obturated With the Resilon/RealSeal System and the Lateral Condensation Technique.

Objectives: The objective of this study was to investigate the effect of different postspace preparation techniques on the apical seal of Resilon/RealSeal obturation system in root canals filled with the lateral condensation technique. Methods: A total of 92 maxillary central incisors were selected for this study, and their crowns were cut. The root canals were instrumented using a Reciproc file system and then filled with a Resilon/RealSeal obturation system, using the lateral condensation technique. Seventy-five samples were divided into five groups (n = 15) according to postspace preparation techniques: Group 1 (no postspace preparation), Group 2 (immediate/mechanical postspace preparation), Group 3 (immediate/thermal postspace preparation), Group 4 (delayed/mechanical postspace preparation), and Group 5 (delayed/thermal postspace preparation). The remaining 16 roots were allocated as follows: 10 roots were used as control groups, while seven roots were used for the preparation of blank solutions. The effectiveness of the apical seal of the obturation material was evaluated using the dye extraction method. The absorbance values of the extracted dye in different groups were measured using a spectrophotometer, and their concentrations (µg/mL) were calculated based on a preestablished calibration curve. Data were statistically analyzed for comparison among groups. Results: All experimental groups showed significant differences in apical leakage (p < 0.05). The lowest mean dye leakage was observed in Group 1 (0.127 ± 0.041 µg/mL) and Group 3 (0.174 ± 0.076 µg/mL). However, no significant difference was found between these two groups (p  > 0.05). Group 3 demonstrated significantly lower leakage compared to Groups 2, 4, and 5 (p  < 0.05). Conclusions: The Resilon/RealSeal system used with the lateral condensation technique demonstrated a reduction in apical dye leakage but failed to completely prevent it, especially when postspace preparation was not performed. Among the evaluated techniques, immediate/thermal postspace preparation proved to be the most effective in maintaining the integrity of the apical seal. In contrast, delayed/thermal, delayed/mechanical, and immediate/mechanical techniques significantly compromised the apical seal. Selecting an optimal postspace preparation technique is essential to preserve the apical seal and enhance the long-term success of endodontic treatments.