Antibacterial Effect and Bioactivity of Innovative and Currently Used Intracanal Medicaments in Regenerative Endodontics

The purpose of this study was to determine the antibacterial effect and bioactivity of triple antibiotic paste (TAP), calcium hydroxide (Ca[OH]2), and calcium hypochlorite (Ca[OCl]2). Root canals were infected with 3-week-old Enterococcus faecalis biofilm and then medicated for 7 days with TAP, Ca(OH)2, or Ca(OCl)2 (n = 10/group). Untreated and uninfected canals were used as positive and negative controls. The antibacterial effect was determined using colony-forming units and a Live/Dead bacterial viability kit. Dental pulp stem cells were seeded on medicated dentin surfaces for 7 days. Sodium thiosulfate and various concentrations of ascorbic acid (1%, 5%, and 10%) were also used to neutralize the samples treated with Ca(OCl)2 before cell seeding (n = 3 in triplicate). Cell viability and morphology were evaluated using a viability assay and Live/Dead cell analysis. Alkaline phosphatase (ALP) activity was also measured to determine the cells’ mineralization activity. All medicaments decreased the initial bacterial load (P