Sealing ability and marginal adaptation of premixed versus manually mixed bioceramic root-end filling materials: a systematic review and meta-analysis

BACKGROUND: Premixed bioceramic root-end filling materials have been introduced as an alternative to manually mixed formulations, with the aim of improving handling properties and reducing operator-dependent variability. This systematic review and meta-analysis compared the sealing ability and marginal adaptation of premixed versus manually mixed bioceramic materials used for root-end filling. METHODS: This review was conducted in accordance with PRISMA 2020 guidelines. Six electronic databases and relevant grey literature sources were systematically searched. Laboratory-based studies comparing premixed and manually mixed bioceramic root-end filling materials were included. Random-effects meta-analyses were performed using standardized mean differences (SMDs) or mean differences (MDs), each reported with 95% confidence intervals (CIs). RESULTS: Twelve studies met the inclusion criteria. Eight studies contributed data to the sealing ability meta-analysis, and six studies contributed to the marginal adaptation meta-analysis. No statistically significant difference in sealing ability was observed between premixed and manually mixed materials (SMD = - 0.12; 95% CI: -0.46 to 0.22; p = 0.48; I² = 58%). In contrast, premixed bioceramic materials demonstrated significantly superior marginal adaptation, reflected by smaller interfacial gaps (MD = - 1.84 μm; 95% CI: -3.20 to - 0.49; p = 0.007; I² = 62%). Heterogeneity across outcomes ranged from moderate to substantial. CONCLUSIONS: Within the limitations of laboratory-based evidence, premixed bioceramic root-end filling materials exhibit superior marginal adaptation compared with manually mixed materials, while sealing ability appears comparable between the two groups. Further well-designed laboratory investigations and clinical studies are required to determine whether improved marginal adaptation translates into superior long-term clinical outcomes.