---
title: Enhanced Removal of E. faecalis Biofilms in the Root Canal Using NaOCl Plus PIPS
description: Discover the groundbreaking effectiveness of using Sodium Hypochlorite combined with Photon-Induced Photoacoustic Streaming (PIPS) in eradicating stubborn E. faecalis biofilms from root canals.
---

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# [Enhanced Removal of E. faecalis Biofilms in the Root Canal Using NaOCl Plus PIPS](https://www.nationaldental.com/fotona-case-studies/enhanced-removal-of-e.-faecalis-biofilms-in-the-root-canal-using-sodium-hypochlorite-plus-pips)

 Written by [National Dental Innovations](https://www.nationaldental.com/fotona-case-studies/author/national-dental-innovations) | Jun 10, 2025 7:12:34 PM

*Discover the groundbreaking effectiveness of using Sodium Hypochlorite combined with Photon-Induced Photoacoustic Streaming (PIPS) in eradicating stubborn E. faecalis biofilms from root canals.  
*

**Authors: **Mohammed Al Shahrani, Enrico DiVito, Christopher V. Hughes, Dan Nathanson, George T-J Huang

**Journal: **Photomedicine and Laser Surgery (2014)

Objective

To determine the effectiveness of photon-induced photoacoustic streaming (PIPS) using Er:YAG laser energy, in combination with sodium hypochlorite (NaOCl), for decontaminating root canal systems heavily colonized with *Enterococcus faecalis* biofilms, in vitro.

Materials and Methods

- **Sample:**  
  60 extracted single-rooted human teeth, mechanically and chemically prepared, sterilized, and inoculated with *E. faecalis* for 3 weeks to establish biofilms.
- **Groups (n=15 each):**
  
    - **Group I:** Control (no decontamination)
    - **Group II:** PIPS + 6% NaOCl
    - **Group III:** PIPS + saline
    - **Group IV:** 6% NaOCl (needle irrigation, no PIPS)
- **Irrigation Protocol:**
  
    - PIPS settings: 50 μsec pulse, 20 mJ, 15 Hz (0.3 W), applied in three 30-second intervals (90 sec total), with the PIPS tip positioned in the coronal pulp chamber.
    - NaOCl (6%) and saline used as irrigants, with a total volume of 21 mL NaOCl per sample for relevant groups.
- **Assessment:**
  
    - Remaining live bacteria quantified by colony-forming unit (CFU) counts.
    - Root canal surfaces examined by scanning electron microscopy (SEM) and confocal laser microscopy (CLM) to visualize biofilm presence and viability.

Key Results

- **CFU Counts (Mean ± SE):**
  
    - **Group I (Control):** 336.8 ± 1.8
    - **Group II (PIPS + NaOCl):** 0.27 ± 0.21
    - **Group III (PIPS + Saline):** 225.0 ± 21
    - **Group IV (NaOCl only):** 46.9 ± 20.3
- **Statistical Analysis:**
  
    - Group II (PIPS + NaOCl) had significantly fewer CFUs than all other groups (*p* < 0.05).
    - PIPS + NaOCl was significantly more effective than NaOCl alone or PIPS with saline.
- **Imaging:**
  
    - SEM and CLM confirmed the near-complete removal of biofilm in the PIPS + NaOCl group, with minimal remaining bacteria, while other groups showed more residual biofilm.

Conclusions

- The combination of PIPS and 6% NaOCl resulted in the most efficient eradication of *E. faecalis* biofilms from the root canal system.
- PIPS alone (with saline) was not as effective, highlighting the importance of NaOCl as the irrigant.
- Laser-activated irrigation with PIPS greatly enhances the disinfection potential of NaOCl, compared to conventional needle irrigation.
- These findings support the use of PIPS with NaOCl for improved root canal disinfection, especially in cases of persistent biofilm.

[ACCESS FULL ARTICLE HERE](https://pmc.ncbi.nlm.nih.gov/articles/PMC4010178/)

 

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