Curcumin—A Natural Medicament for Root Canal Disinfection: Effects of Irrigation, Drug Release, and Photoactivation

Abstract

Introduction Curcumin incorporation into polymeric fibers was tested for its antimicrobial properties and potential use in root canal disinfection. Methods Curcumin-modified fibers were processed via electrospinning and tested against a 7-day old established Actinomyces naeslundii (An) biofilm. The medicaments tested were as follows: curcumin-modified fibers at 2.5 and 5.0 mg/mL, curcumin-based irrigant at 2.5 and 5.0 mg/mL, saline solution (negative control), and the following positive controls: 2% chlorhexidine, 1% NaOCl, and triple antibiotic paste (TAP, 1 mg/mL). All medicaments, except for the positive controls, were allocated according to the light exposure protocol: photoactivation with an LED every 30 s for 4 min or without photoactivation. After treatment, the medicaments were removed and 1 mL of saline solution was added; the biofilm was scraped from the well and used to prepare a 1:2000 dilution. Spiral plating was done using anaerobic blood agar plates. After 24 h, colony-forming units (CFU/mL, n=11/group) were counted to determine the antimicrobial effects. Results Data exhibited significant antimicrobial effects on positive control groups, followed by the curcumin irrigants, and lastly, the photoactivated curcumin-modified fibers. There was a significant reduction of viable bacteria in curcumin-based irrigants, which was greater than the TAP-treated group. Curcumin-free fibers, saline, and the non-photoactivated curcumin-modified fibers did not display antimicrobial activity. Conclusions Curcumin seems to be a potential alternative to TAP when controlling infection, but it requires a minimal concentration (2.5 mg/mL) to be effective. Photoactivation of curcumin-based medicaments seems to be essential to obtain greater antibiofilm activity.