What role does Fusobacterium nucleatum play in dental biofilm formation?

Fusobacterium nucleatum is a KEY BRIDGING ORGANISM in dental biofilm. Early colonizers (Streptococcus species) bind to the pellicle. F. nucleatum serves as a BRIDGE — it co-aggregates with early colonizers AND facilitates the attachment of late colonizers (like Porphyromonas gingivalis, Treponema denticola) which are the major periodontal pathogens. It does NOT inhibit early colonizers (A wrong), it is very significant (C wrong), and it's not primarily cariogenic (D wrong). B is correct.