Assessment of a Light-Curable Hydrogel to Be Used for Root Canal Obturation

Root canal obturation involves filling of the chemomechanically prepared root canal space. Despite reduced microbial load, residual bacteria can still lead to reinfection and treatment failure. Currently, obturation techniques use a combination of gutta-percha and sealer, which requires the preparation of the root canal to specific sizes and tapers to enable the fitting of customized cones. This study aims to characterize the physical, chemical, and antimicrobial properties of a new light-curable injectable material (OdneFill, Switzerland) used to obturate the root canal. Odnefill and 2 root canal sealers (AH Plus and BioRoot RCS) were characterized by scanning electron microscopy (SEM) and energy-dispersive spectroscopy following exposure to chlorhexidine, sodium hypochlorite, and water. The flow, film thickness, radiopacity, solubility, and contact angle were evaluated. The susceptibility to microbial degradation was assessed by weight changes after contact with bacterial enzymes (lipase and cholesterol esterase). A multispecies biofilm composed of Streptococcus mutans, Enterococcus faecalis, Fusobacterium nucleatum, and Veillonella dispar was used to assess changes to the material microstructure (SEM). Further, bacterial viability in contact with the materials was evaluated using live/dead staining and confocal microscopy. A direct contact assay was carried out, and the utilization of the materials as a carbon source for the bacterial biofilm was also assessed. Statistical analysis was performed using 1-way analysis of variance and Tukey post hoc tests (P = 0.05). OdneFill was composed of an organic matrix with zirconium oxide filler. It exhibited comparable physical properties to AH Plus and BioRoot RCS and was stable in contact with irrigating solutions and with the bacterial enzymes (cholesterol esterase and lipase). Its antimicrobial characteristics were better than those of AH Plus when placed in contact with a multispecies biofilm. Based on the findings, OdneFill presents itself as suitable root canal-filling material and warrants further clinical investigation.