A quercetin loaded root canal sealer based on polyphosphate coacervate composite with anti-inflammatory and mineralization promoting properties.

OBJECTIVES

This study aimed to develop a root canal sealer based on quercetin-loaded polyphosphate coacervate composite (CMQ) and systematically evaluate its physicochemical properties, sealing performance, and biological activity.

METHODS

The sealer was synthesized via loading the quercetin in the injectable and self-setting polyphosphate coacervate composite. The structural characteristics, quercetin release behavior, biological activities, and sealing performance of CMQ were evaluated. The selected physicochemical properties, including film thickness, flowability and solubility, were assessed with reference to ISO 6876:2025. In vitro antioxidant activity was assessed using a free radical scavenging assay. Biocompatibility was evaluated using cytological assays and a rat subcutaneous implantation model. The antioxidant and anti-inflammatory activities, as well as the effects on human periodontal ligament cells (hPDLCs) migration and osteogenic differentiation, were further investigated.

RESULTS

The sealer showed appropriate setting characteristics without an observable heating effect or structural collapse and favorable dimensional stability after setting, with only limited dimensional changes observed, followed by sustained quercetin release over a 21-day observation period. The post-setting sealer exhibited a uniform microstructure, with the tested parameters of film thickness, flow and solubility met the specified requirements. Furthermore, it demonstrated favorable biocompatibility, promoted hPDLC adhesion and migration, reduced intracellular reactive oxygen species (ROS), modulated inflammatory factor expression, and enhanced osteogenic activity. In vivo implantation elicited only mild inflammation, with no evidence of abnormal tissue lesions.

SIGNIFICANCE: The polyphosphate coacervate-based CMQ sealer demonstrated suitable physicochemical properties, reliable sealing performance, and favorable biocompatibility, together with antioxidant, anti-inflammatory, and osteogenic activity, suggesting its potential as a bioactive material for endodontic applications.