The efficacy of ultrasonic and PIPS (photon-induced acoustic streaming) irrigation to remove artificially placed dentine debris plugs out of an artificial and natural root model

  • Christoph Kurzmann
  • Maarten A. Meire
  • Stefan Lettner
  • Eleftherios Terry R. Farmakis
  • Andreas Moritz
  • Roeland J. G. De MoorEmail author
Original Article


The aim was to validate an artificial resin ‘root canal wall groove model’ (RCWGM) mimicking the situation of natural roots with a groove of identical dimensions on debris removal out of these grooves, and to evaluate Erbium ‘laser-activated irrigation’ (LAI) with two conical tips at PIPS (photon-induced photoacoustic streaming) settings, with different activation times and different root canal positions on debris removal out of the grooves. A split RCWGM was used (resin blocks and roots of maxillary canines) with a canal size 40/0.06. The grooves in the apical third were filled with stained dentinal debris. Seventeen irrigation protocols (n = 20) were used: syringe-needle irrigation (3× 20 s), manual dynamic activation (1× 60 s), ultrasonically activated irrigation (UAI) with 25/25 Irrisafe (3× 20 s) and LAI (2940 nm Er:YAG) with X-Pulse or PIPS tips at PIPS settings (20 mJ, 50 μs, 20 Hz) and with the fibre (IN) or (OUT) the canal: IN during 1× 20 s, and OUT during 1× 20 s, 2× 20 s, 3× 20 s, 30 s, 2× 30 s and 1× 60 s. The quantity of remaining dentine debris in the groove was evaluated on a numerical scale. Statistical analysis was performed by means of proportional odds logistic regression, equivalence testing and Wald tests. The level of significance was set at 0.05. Resin models and the RCWGM with natural teeth can be called equivalent (log odds ratio 0.185). There were mostly no statistically significant differences for debris removal between UAI and LAI (p > 0.05) and between LAI with PIPS and X-Pulse (p > 0.05). Although not statistically different, the numbers of completely cleaned grooves were higher with LAI than with UAI for a 1-min activation, confirming findings from other studies. There is no difference in cleaning efficacy between X-Pulse and PIPS tips at PIPS settings.


Root canal debridement Erbium laser Irrigant activation Laser-activated irrigation PIPS Ultrasonically activated irrigation Ultrasonic 



The authors thank Mr. Ahmed Basran for his skilful contribution and support in data acquisition.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

The authors declare that the protocol of this article was approved by the Ghent University Hospital Ethical Committee, EC/2014/0578.

Informed consent

Informed consent was obtained from 20 patients whose teeth were extracted as part of a dental procedure at the Ghent University Hospital Dental Clinic. The informed consent document was approved by the Ghent University Hospital Ethical Committee, EC/2014/0578.


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Copyright information

© Springer-Verlag London Ltd., part of Springer Nature 2019

Authors and Affiliations

  1. 1.Division of Conservative Dentistry and Periodontology, University Clinic of DentistryMedical University of ViennaViennaAustria
  2. 2.Austrian Cluster for Tissue RegenerationViennaAustria
  3. 3.Department of Endodontology, Dental SchoolGhent UniversityGentBelgium
  4. 4.Karl Donath Laboratory for Hard Tissue and Biomaterial Research, Division of Oral Surgery, University Clinic of DentistryMedical University of ViennaViennaAustria
  5. 5.Department of Endodontics, Dental SchoolNational and Kapodistrian University of AthensPeaniaGreece
  6. 6.MOND LatemGhent Dental Laser CentreSint-Martens-LatemBelgium

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