Efficacy of photon induced photoacoustic streaming (PIPS) on root canals infected with Enterococcus faecalis: A pilot study

Eradication of microorganisms from an infected root canal before obturation is a primary focus of endodontic treatment, as well as the best predictor for the long-term success of the endodontic therapy. The purpose of this in vitro laboratory study was to evaluate the efficacy of a new tapered and stripped Er:YAG laser tip using PIPS (Photon Induced Photoacoustic Streaming) in root canals infected with Enterococcus faecalis (ATCC4082). Methods: Twenty-four freshly extracted single-rooted human teeth were collected and inoculated with E. faecalis. After 4 weeks, the teeth were divided in four groups, two experimental, one positive, and one negative group. Laser treatment was performed for a period of 20 seconds with 6% sodium hypochlorite in groups 1 and 2, while PBS was used for group 3 and 4. Furthermore, dentin debris was produced, and colony-forming units were determined. Results: The combinations of 20 seconds laser activated irrigation with Er:YAG Laser and 6% sodium hypochlorite showed 100% inhibition using PIPS of growth of E. faecalis compared to 50% inhibition with the combination of Er:YAG Laser and PBS. Conclusions: The PIPS technology is efficient tool in elimination of Enterococcus faecalis from infected root canals. Introduction Many clinical approaches have been evaluated for disinfection and control of the root canal biofilm during endodontic treatment1,2. The presence of bacteria in root canals has been considered to be responsible for endodontic treatment failure1,3. Eradication of microorganisms from an infected root canal before obturation is a primary focus of endodontic treatment3,4 as well as the best predictor for the long-term success of the endodontic therapy5. Location, harboring, and multiplication of bacteria within root canals are the factors most cited for making disinfection of this anatomical structure a clinical problem. Bacteria can colonize and survive in dentinal tubules, lateral canal ramifications, canal isthmuses, and other irregularities in the root canal1,3, thus making the mechanical instrumentation approach limited in its effectiveness, unless supplemented with antimicrobial solutions that help in reducing the bacterial load6,7. Enterococcus faecalis, a gram-positive facultative anaerobe is able to resist and adapt to the harshest environmental conditions; this explains its presence and survival in endodontic infections and periradicular lesions8. Traditional therapeutic solutions such as sodium hypochlorite and chlorhexidine (either gel or liquid) or combinations of different irrigation vehicles have been shown to be effective in eliminating or reducing the presence of E. faecalis from root canals and dentinal tubules9. Different techniques have been proposed to improve the efficacy of irrigation solutions, including changes of concentration, temperature, surfactant, and agitation10. Despite the fact that traditional chemomechanical cleansing measures have shown acceptable results in endodontic outcomes, several literature reports have suggested that the additional use of lasers can be a valuable addition in removing bacterial load in areas Efficacy of photon induced photoacoustic streaming (PIPS) on root canals infected with Enterococcus faecalis: A pilot study Drs. David E. Jaramillo, Raydolfo M. Aprecio, Nikola Angelov, Enrico DiVito, and Thomas V. McClammy explore whether the Er:YAG laser tip is an efficient tool in elimination of Enterococcus faecalis from infected root canals Educational aims and objectives The purpose of this article is to: Explore whether additional use of lasers can be a valuable addition in removing bacterial load in areas where traditional methods may fail to succeed. Expected outcomes Correctly answering the questions on page 33, worth 2 hours of CE, will demonstrate that you can: evaluated for disinfection and control of the root canal biofilm during endodontic treatment. canals infected with Enteroccocus faecalis. mechanical cleansing measures have shown acceptable results in endodontic outcomes, the additional use of lasers can be a valuable addition in removing bacterial load in areas where traditional methods may fail to succeed. where traditional methods may fail to succeed1,11,12. The use of Photo Dynamic Therapy (PDT) added to conventional endodontic treatment leads to a further major reduction of microbial load, proving that PDT is an efficient treatment to kill multi-drug resistant microorganisms13. Studies have shown that combined treatments, such as the use of sodium hypochlorite, citric acid, and diode laser energy together have a synergistic effect, increasing treatment efficacy and leading to significantly better decontamination of the root canal14. Er:YAG laser is effective in removing debris and smear layer from root canal walls15. Standardized instrumentation, followed by a final Er:YAG laser irradiation in wet canals with EDTA irrigation can result in more cleaning of the root canal walls and a higher quantity of open tubules in comparison with the traditional irrigation method16. Noetzel et al, evaluated the efficacy of the CaOH2, Er:YAG laser and gaseous ozone in root canal disinfection either alone or combined with mechanical instrumentation and different antimicrobial solutions in canals inoculated with E. faecalis3. Within the limitation of their study, the authors concluded that Er:YAG laser irradiation does not provide satisfactory reduction of E. faecalis-infected root canals when compared to CaOH2 and gaseous ozone, both of which demonstrated higher efficacy. They also reported that the use of antimicrobial solutions such as 1% sodium hypochlorite and 0.2% chlorhexidine showed increased antibacterial efficacy3. In addition, Yavari et al, also suggested that even though 1% sodium hypochlorite solution had a more significant antibacterial effect on the microbiological flora present in infected root canals, the use of laser (Er,Cr:YSGG) also showed noticeable antimicrobial effects on the E. faecalis12. Conversely, De Moor et al, showed that