Evaluation of pushout bond strength and marginal adaptation of pullulan-modified mineral trioxide aggregate as root-end filling material – In vitro analysis

ABSTRACT Aim: The aim of this study was to optimize a root-end filling material comprising phosphorylated pullulan (PPL) incorporated mineral trioxide aggregate (MTA) and to evaluate its marginal adaptation and pushout bond strength in vitro . Methods: Forty extracted human maxillary central incisors were decoronated and standardized to 16 mm. Root canals were prepared using WaveOne Gold #45.06 files, irrigated with saline, and obturated with gutta-percha by lateral condensation. After 1 week at 37°C and 100% humidity, 3 mm root-end resections and cavities were prepared ultrasonically. Samples were divided into two groups: Group I (MTA) and Group II (PPL with MTA [P-MTA]). Pushout bond strength was measured using an INSTRON Universal Testing Machine, and marginal adaptation was analyzed using scanning electron microscopy (SEM). Results: Pushout bond strength analysis demonstrated that P-MTA exhibited significantly greater bond strength (2.14 ± 0.73 MPa) than conventional MTA (0.68 ± 0.57 MPa) ( P < 0.05). SEM analysis revealed a significantly higher mean marginal distance in the MTA group (13.29 ± 9.59 µm) compared to the P-MTA group (10.09 ± 8.87 µm), indicating superior marginal adaptation of P-MTA ( P < 0.05). Conclusion: P-MTA demonstrated superior marginal adaptation and pushout bond strength compared to conventional MTA. Further in vitro and clinical studies are required to validate these findings.