Laminin functionalization of zirconia abutments modulates early oral biofilm formation in vitro.

BACKGROUND: Surface properties of dental implant abutment materials critically influence supragingival biofilm formation by determining the outcome of the early 'race for the surface', in which gingival epithelial cells and fibroblasts compete with bacteria for initial adhesion. This study hypothesized that biofunctionalization with extracellular matrix (ECM) proteins fibronectin (FN) or laminin (LN) modulates early oral biofilm formation on titanium alloy (Ti6Al4V) and yttria-stabilized zirconia (Y-TZP) abutments. METHODS: Saliva-derived microcosm biofilms were grown on control and biofunctionalized discs. Biofilm biomass, viability, structure, microbial community composition and metabolic activity were assessed using microscopy-based methods, impedance flow cytometry, 16S rRNA sequencing and short-chain fatty acid analysis. RESULTS: Laminin-functionalized Y-TZP showed the most pronounced delay in early biofilm formation. Biofilm accumulation was delayed during the first three days and was associated with the lowest number of viable cells on day 4, minimal extracellular polymeric substance formation, reduced Veillonella abundance (~9% on day 1) and decreased short-chain fatty acid production. CONCLUSION: ECM-based coatings do not exert bactericidal effects but transiently reshape early oral biofilm formation. Laminin-functionalized zirconia may act as a biologically selective interface that favors beneficial early host-microbe interactions, potentially creating a microbial environment more compatible with peri-implant soft-tissue health.