Antimicrobial effect of 2.5% sodium hypochlorite irradiated with the 445 Nm diode laser against bacterial biofilms in root canal - in vitro pilot study.

AIMS: This research investigates the efficacy of a novel blue diode laser (445 nm wavelength) in enhancing the antimicrobial action of 2.5% sodium hypochlorite against biofilms of two prevalent microbial species found in root canals- in vitro. The research also includes a comparative analysis with a more established diode laser protocol (970 nm), assessing their respective effectiveness in eliminating root canal pathogens.

METHODOLOGY: 62 extracted single-rooted human teeth were prepared with rotary endodontic instruments, sterilized, contaminated with a combination of two microbial cultures (E. faecalis, C. albicans) and incubated for 14 days at 37 ◦C. The samples were randomly distributed into 4 groups: G1- negative control, G2-2.5% NaOCl rinse, G3-445 nm laser boosted 2.5% NaOCl rinse, G4-970 nm laser boosted 2.5% NaOCl rinse. SEM imaging was done to visualize effects in each group. The number of viable microbes in each sample was determined by the colony forming unit count technique (CFU).

RESULTS: A statistically significant reduction of microbial numbers after all treatments was observed (Mann-Whitney U test, significance level set to 5%). G3 and G4 showed similar results, both better than G2.

CONCLUSIONS: The 445 nm diode laser NaOCl irradiation protocol has improved antimicrobial effectiveness when compared to sole 2.5% NaOCl rinse and equal effectiveness as the 970 nm NaOCl irradiation protocol, ex vivo.