Impact of EDTA Formulations and Activation Methods on Stem Cell Response, Antimicrobial Activity and Dentine Integrity: An In Vitro Study.

This study evaluated the effects of 17% trisodium EDTA and 15% disodium EDTA (EDTAd), with or without activation, on SCAP response, antimicrobial activity and dentine chemical alterations. SCAP viability (Live/Dead) and metabolic activity (Alamar Blue) were assessed, along with antibiofilm and intratubular disinfection against Enterococcus faecalis and Streptococcus mutans, after irrigation with EDTA or EDTAd delivered by conventional irrigation (CI), ultrasonic activation (UA) or diode laser activation (LA). Dentine alterations were analysed by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). EDTA preserved higher SCAP metabolic activity, particularly at early time points (p < 0.05), while cytotoxicity did not differ among groups. Antibiofilm and intratubular antimicrobial effects were similar across irrigants and activation methods (p > 0.05). EDTAd caused greater alterations in the amide III/phosphate ratio (p < 0.05), with increased smear-layer removal and surface irregularities. EDTA showed greater biological compatibility and fewer dentine alterations, whereas EDTAd induced more pronounced structural changes without antimicrobial differences.