Which immunoglobulin is the predominant one present in saliva?

Secretory IgA is the predominant immunoglobulin in saliva and other mucosal secretions, providing a first-line 'immune exclusion' defense against pathogens at mucosal surfaces — distinct from IgG (the main immunoglobulin in blood/systemic circulation), IgE (allergic/parasitic responses), and IgM (early systemic immune response).