255 nm LED kills Enterococcus faecalis and induces the production of cellular biomarkers in HEPM cells and gingival fibroblasts

INTRODUCTION: Successful treatment of infected or inflamed endodontic tissues requires chemo-mechanical debridement of the canal spaces and proper sealing of the coronal and apical canal openings. Only a few methods are available to further disinfect areas or initiate regeneration of local tissues. In this study, we assessed the ability of 255 nm and 405 nm light emitting diode (LED) treatment to kill planktonic cultures of Enterococcus faecalis (E. faecalis) and induce the production of cellular biomarkers related to endodontic tissue regeneration. METHODS: We determined the antimicrobial effects of 255 nm and 405 nm LED treatment on E. faecalis and the effects of 255 nm and 405 nm LED treatment on the production of osteoinductive, angiogenic, proliferative, and proinflammatory biomarkers from human embryonic palatal mesenchyme (HEPM) cells and gingival fibroblasts. RESULTS: We demonstrated that 1) 255 nm LED, but not 405 nm LED, treatment killed E. faecalis, 2) 255 nm LED and sodium hypochlorite (NaOCl) more efficiently killed E. faecalis, 3) neither 255 nm nor 405 nm LED treatment affected the viability of HEPM cells and gingival fibroblasts, and 4) 255 nm LED treatment, alone or in combination with 405 nm LED treatment, of HEPM cells and gingival fibroblasts induced the production of biomarkers related to endodontic tissue regeneration. CONCLUSIONS: The results in this study suggest a new treatment modality using short periods of 255 nm LED treatment as an adjunct to chemo-mechanical debridement for the disinfection of inflamed sites and the production of biomarkers related to endodontic tissue regeneration.