ARCIMS 26
in
Sunday 2025-10-19 18:42
Comparison of 10 600 nm CO2 Laser, Sodium Hypochlorite and Chlorhexidine Irrigants against Enterococcus faecalis in Human Permanent Premolar Root Canals: an in-vitro study
Parham Jabbari Moradlou 1, Danyal Azish 2, Seyyed Amir Seyyedi 3 ©, Amir Ardalan Abdollahi 4, Mohammad Karimpour 2 ℗
Abstract
Introduction: Enterococcus faecalis (E.fecalis) is a Gram-positive, facultative anaerobic bacterium, naturally inhabits the gastrointestinal tract and implicated in up to 38% of persistent endodontic infections and can survive conventional chemomechanical preparation. Laser irradiation that penetrates dentinal tubules might serve as an adjunct. This in vitro study evaluated the antimicrobial efficacy of a 10 600 nm CO2 laser, 5.25 % NaOCl, 2 % CHX and normal saline. Methods: sixty-five single rooted permanent premolars were instrumented with the step back K file technique to size 40 and irrigated with 5.25 % NaOCl, 17 % EDTA and saline, then autoclaved. After triple contamination for 7 days with E. faecalis (ATCC 29212), teeth were randomly allocated (n = 15) to: (1) CO2 laser (10 600 nm, 248 W peak, 10 µs pulse width, 250 µs interval, 15 pulses per canal, spiral withdrawal at 2 mm s⁻¹); (2) 5.25 % NaOCl; (3) 2 % CHX; (4) saline. Three positive and two negative controls were included. Colony forming units (CFU mL⁻¹) were counted before and 24 h after treatment. Data were analyzed with the Kruskal–Wallis and Mann–Whitney U tests (α = 0.05). Results: Baseline contamination was comparable among groups (p 0.05). Percentage mean CFU reduction percentages were: CHX 99.49 %, NaOCl 99.25 %, CO2 laser 88.99 %, saline 5.90 %. All treatment groups differed significantly from baseline (p 0.001). NaOCl and CHX were statistically equivalent (p = 0.646) and superior to the laser (p 0.001). The laser was significantly more effective than saline (p 0.001). Conclusion: The 10 600 nm CO2 laser produced a clinically relevant (≈ 89 %) reduction of E. faecalis. It was significantly less effective than standard NaOCl and CHX irrigation. Within this in vitro model, CO2 laser irradiation may be considered an adjunct rather than a substitute for conventional irrigants; its translation to the clinical setting requires in vivo studies.
Keywords: Enterococcus faecalis; CO2 laser; sodium hypochlorite; chlorhexidine; in vitro
