FESEM evaluation of smear layer removal from conservatively shaped canals: laser activated irrigation (PIPS and SWEEPS) compared to sonic and passive ultrasonic activation—an ex vivo study

Abstract

Background Irrigation of the pulp space is a mandatory step to get rid of all its organic and inorganic content. Activation of the irrigants play a key role in the era of minimally invasive endodontics. The aim of this study was to assess the effectiveness of different irrigants activation methods in removing the smear layer at 1, 3, 5 and 8 mm from the apex from conservatively shaped canals. Methods Eighty-five human mandibular premolars were selected. Specimens were shaped to TruShape 25/.06 and divided into 5 groups (1 control and 4 test groups) according to the final activation technique (EndoActivator, EA), Ultrasonic (EndoUltra, PUI) and Laser (PIPS and SWEEPS). EDTA (Ethylenediaminetetraacetic acid) followed by NaOCl (Sodium Hypochlorite) and again EDTA were activated for each test group. Specimens were then split longitudinally and observed by Field Emission Scanning Electron Microscopy (FESEM). Blinded evaluation of the presence of smear layer was performed at 1000X magnification, according to a 5-score index system. Comparison between groups were analysed statistically using the Kruskal–Wallis non-parametric analysis of variance. Bonferroni multiple comparison tests were used. Results At 1 mm only PIPS and SWEEPS performed better than the control group. At 3, 5 and 8 mm from the apex, every activation technique showed statistically significant reduction of smear layer when compared to the control group. PIPS and SWEEPS obtained better cleanliness result compared to EA, while only PIPS was superior to PUI in terms of cleanliness. Conclusions PIPS and SWEEPS showed the best results in conservative canal preparations. Nowadays, contemporary rotary instruments allow fast and minimally invasive shaping of the endodontic space. In this scenario irrigants’ activation may be regarded as a mandatory step to a favourable clinical outcome.

Debris Removal by Activation of Endodontic Irrigants in Complex Root Canal Systems: A Standardized In-Vitro-Study

“…As a further development of the laser-based systems, SWEEPS showed even better results in hard tissue debris removal compared to PIPS [32]. Furthermore, SWEEPS seemed to be advantageous over sonic activation with EndoActivator in terms of smear layer removal [72].…”

Effectiveness of Different Final Irrigation Procedures on Enterococcus faecalis Infected Root Canals: An In Vitro Evaluation

“…These results are consistent with those of previous studies where no significant differences were observed between the removal of the smear layer and debris in the apical and medium thirds of the root canal after manual-dynamic irrigation and sonic activation [ 32 , 53 ]. However, it was also reported in the literature that smear layer removal using PUI was significantly superior to manual irrigation [ 32 ] and that laser-activated irrigation was superior to sonic and ultrasonic irrigation techniques [ 54 ]. Better cleaning of root canal walls was also observed for laser-activated irrigation in comparison with standard needle irrigation [ 14 ].…”

Efficacy of Photoinduced Photoacoustic Streaming and Diode Laser Irrigation Techniques on Smear Layer Removal, Sealer Penetration and Push-out Bond Strength

“…Such requirement was replaced by the photoacoustic shockwaves induced with the pulsed laser within the irrigant travelling throughout the root canal framework, allowing its 3-D movement without the requirement for intracanal tip insertion. 26,[32][33][34][35][36][37] PIPS is a laser agitation technique, which employs the Er: YAG laser at 2940 nm. This technology relies on the high wavelength absorption of the Er: YAG laser in the pulp chamber filled with water-based irritants.…”

“…Apical sealing was highly improved on utilizing lasers for irrigant activation before obturation. [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Further studies should be carried out to improve the effects of lasers and its combination with different irrigating solutions in eliminating the smear layer from the root canal walls. Further research on the diode laser for the practical use in endodontics is needed before it is clinically applied.…”