Fotona Case Studies

Disinfection Efficacy of Photon-Induced Photoacoustic Streaming on Root Canals Infected with E. Faecalis

Written by National Dental Innovations | Jun 10, 2025 7:12:39 PM

Explore how photon-induced photoacoustic streaming (PIPS) outperforms conventional needle irrigation (CNI) in disinfecting root canals infected with Enterococcus faecalis.

Authors: Olivi G, DiVito E, Peters O, Kaitsas V, Angiero F, Signore A, Benedicenti S

Journal: Journal of the American Dental Association (JADA)

Objective

To evaluate and compare the disinfection efficacy of photon-induced photoacoustic streaming (PIPS) using an Er:YAG laser with conventional needle irrigation (CNI) in root canals infected with Enterococcus faecalis.

By exploring the effectiveness of PIPS, the study sought to contribute to the ongoing efforts to improve root canal disinfection techniques, especially in narrow and minimally prepared canals where traditional methods may fall short.

Materials and Methods

The authors prepared 26 human anterior teeth to size 25/06, sterilized and infected them with Enterococcus faecalis, and incubated them for four weeks. Two irrigation protocols were tested: Group A received two 30-second cycles of 5% NaOCl and one 30-second cycle of 17% EDTA, all activated with an Er:YAG laser (20 mJ, 15 Hz, 50 µs pulse, 600 µm PIPS tip). Group B received the same solutions passively via syringe and 25-gauge needle.

Key Results

  • The authors found that group A had significantly better disinfection compared with group B (P < .05). The results of cultures obtained after 48 hours showed that disinfection was maintained better in group A compared with group B (P < .0001). Scanning electron microscopic images showed absence of bacterial biofilm remaining after LAI using PIPS.
  • PIPS achieved significantly greater bacterial reduction than conventional needle irrigation, both for planktonic E. faecalis and biofilm forms.
  • PIPS was especially effective in narrow and minimally prepared canals, delivering better disinfection without requiring enlargement of the apical area.

Conclusion

Er:YAG laser activation of 5% NAOCl and 17% EDTA was more effective than conventional irrigation for eradicating E. faecalis and preventing new bacterial growth ex-vivo.
 
Photon-induced photoacoustic streaming (PIPS) is more effective than conventional needle irrigation for disinfecting root canals infected with E. faecalis, particularly in minimally prepared canals. This technique enhances root canal disinfection while preserving tooth structure.
 
Additional clinical studies are needed to clarify the effect on endodontic treatment outcomes.
 

 
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