[Possibilities and significance of immunological diagnosis for the differential diagnosis of periodontal diseases].

A clearer understanding of the aetiology of periodontal diseases can only be gained by further studies on the effects of plaques on the organism. Furthermore, the pathogenic plaque components must be assessed. It seems worth while maintaining the working hypothesis that periodontal disease is a plaque-induced clinical picture and that its various types are due to variations in the power of resistance of the organism. The better understanding of this changed reactivity and of the pathogenic plaque components must be aimed at.