Eur Endod J. Ahead of Print: EEJ-60565

Investigating the Effect of PIPS Technique by Using Er,Cr: YSGG Irradiation for Sealer Removal in Endodontic Retreatment

Sara Sami, Hussein Ali Jawad
Institute of Laser for Postgraduate Studies, University of Baghdad, Baghdad, Iraq

Objective: This study aimed to evaluate the effectiveness of the Er,Cr: YSGG 2780 nm laser pulse duration
during root canal retreatment using the laser-activated irrigation method (PIPS).
Methods: The study investigated the cleanliness of root canal walls in single-rooted premolars using PIPS.
Teeth were initially instrumented, filled with bioceramic (BC) sealer and gutta-percha, and then retreated using
nickel-titanium (NiTi) retreatment rotary files. The teeth were randomly assigned to four equal groups:
control (manual irrigation), ultrasonic irrigation (UI), laser-activated irrigation with a 60 μs pulse duration, and
laser-activated irrigation with a 700 μs pulse duration. Irrigation solutions consisted of 17% EDTA and 2.5%
sodium hypochlorite. Statistical analysis was performed using SPSS version 21.0. Normality was checked using
the Kolmogorov–Smirnov and Shapiro–Wilk tests. Group comparisons were conducted using Dunnett’s t-test
and the LSD test, with a significance level set at p≤0.05.
Results: Statistical analysis of scanning electron microscopy (SEM) images revealed superior cleaning efficiency
in both laser groups, with a significant improvement in cleanliness rates compared to the other groups.
Group 4 (700 μs) achieved the highest percentage of open dentinal tubules (>75%) in the coronal and middle
thirds, while Group 3 (60 μs) showed 50– 75% tubule openness. Groups 1 and 2 showed significantly lower
cleaning effectiveness, particularly in the apical third.
Conclusion: The pulse duration plays a crucial role in the activation of laser irrigants during root canal retreatment.
The 700 μs PIPS activation resulted in better cleaning outcomes compared to the 60 μs laser activation.

Keywords: Er,Cr: YSGG laser, laser-activated irrigation, photoacoustic streaming, root canal irrigants, root canal retreatment, scanning electron microscopy, smear layer removal, ultrasonic irrigation

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