Antimicrobial Efficacy of a Novel Antibiotic-Eluting Injectable Platelet-Rich Fibrin Scaffold against a Dual-Species Biofilm in an Infected Immature Root Canal Model

Background and Aims. This study was aimed at evaluating the antibacterial property of an injectable platelet-rich fibrin (I-PRF) scaffold containing triple antibiotic mixture against an Actinomyces naeslundii (A. naeslundii) and Enterococcus faecalis (E. faecalis) biofilm in an infected immature root canal model. Methods. A dual-species biofilm was inoculated inside the root canals via a series of centrifugal cycles. The samples were allocated to three experimental groups (i.e., G1: triple antibiotic mixture, G2: I-PRF containing triple antibiotic mixture, and G3: antibiotic-free I-PRF scaffold) and two control groups (G4: seven-day biofilm untreated and G5: bacteria-free untreated). Results. Bacterial gene quantification change and the overall reduction of live bacteria were evaluated. The highest antibacterial activity against A. naeslundii belonged to G2. However, G1 and G2 had similar antibacterial property against E. faecalis (p value = 0.814). In general, experimental groups revealed higher levels of antibacterial activity against E. faecalis than against A. naeslundii (p value < 0.001). Notably, G2 could dramatically decrease the number of live bacteria up to near 92%. Conclusions. The current study provides insight into the antibacterial property of an antibiotic-eluting I-PRF scaffold against a dual-species biofilm colonized inside the root canal. The fabricated scaffold contains not only the antibiotics but also the growth factors, which favor the regeneration.