Analysis of Conventional and Enhanced-Biocompatibility ZnO/Ag Heterojunction Nanorod-Based Advanced Root Canal Sealers

This investigation aims to evaluate the biocompatibility and assess the cytotoxicity of synthesized ZnO/Ag heterojunction nanorods with commercially available root canal sealers in India. Among the commercially available root canal sealers, zinc oxide (ZnO) eugenol-based sealers are widely utilized as per Grossmann's requirements. However, these ZnO eugenol-based sealers often experience solubility issues and tissue reactions in contact with periapical tissues. To overcome the inexplicable reactivity of ZnO eugenol-based sealers, nano ZnO and nano ZnO/Ag heterojunction materials have been developed via a wet-chemical approach and studied to assess their biocompatibility and cytotoxicity. The findings of our study revealed that nano ZnO/Ag heterojunction material possesses a higher degree of biocompatibility and low cytotoxicity as compared to conventional ZnO eugenol-based sealers, attributed to its high surface-to-volume ratio, the enhanced penetration of nanosized sealers into dentinal tubules, and the synergistic spillover sensitization effect of nano ZnO combined with Ag nanoclusters. From this comparative evaluation of root canal sealers, the usage of nano ZnO/Ag heterojunction materials was found to be significantly advantageous over commercial zinc oxide eugenol-based sealers and may find profound usage with a long shelf-life.