Skin prick test kit for the determination of the predisposition of an individual to develop marginal periodontitis, said kit comprising: (a) a first reagent containing a known quantity of a surface structure common to anaerobic Gram negative pathogens which is capable of triggering the inflammatory response associated with periodontitis and gingivitis; (b) a second reagent containing an agonist to said individual; (c) a negative control; and (d) instructions for the use of said kit; and a method for such determination of predisposition.
