Potential apply of hydrogel-carried chlorhexidine and metronidazole in root canal disinfection

Microorganisms may persist in the root canal system after root canal therapy (RCT). The purpose of this study was to explore the metronidazole (MTR)- and chlorhexidine (CHX)-loaded hydrogels as the potential application in intracanal medicaments for root canal disinfection. Ultraviolet cross-linked hydrogels (gGels) were synthesized by GelMA solution and photoinitiator, which were loaded with MTR (MTR@gGels) and CHX (CHX@gGels). gGels, MTR@gGels and CHX@gGels were characterized by scanning electron microscopy. The antimicrobial activity against E. faecalis, S. mutans and P. intermedia was assessed. Meanwhile, the biocompatibility of human dental pulp stem cells (hDPSCs) was evaluated. DCT, CCK-8, CFU and live/dead-stained biofilm results showed that the viability of E. faecalis, S. mutans and P. intermedia was significantly reduced in MTR@gGels and CHX@gGels in vitro. CCK-8 results showed considerable biocompatibility with hDPSCs. The filling and clearance of gGels in root canals were demonstrated in vivo. Therefore, MTR- and CHX-loaded hydrogels may be a potential application in intracanal medicaments for root canal disinfection.