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.