A number of markers show promise as sensitive measures of disease and the effectiveness of therapy. At this time, host-derived enzymes and other inflammatory mediators orginating from the gingival crevice appear to hold the greatest promise as salivary diagnostic tests for periodontal disease. Longer-term longitudinal studies, however, are required to establish the relationship between specific markers and progression of periodontal disease. Furthermore, analysis of saliva may offer a cost-effective approach to assessment of periodontal disease in large populations.