In periodontics and implant dentistry, traditional clinical criteria are often insufficient for determining sites of active disease, for monitoring quantitatively the response to therapy or for measuring the degree of susceptibility to future disease progression. Saliva as a mirror of oral and systemic health is a valuable source for clinically relevant information because it contains biomarkers specific for the unique physiological aspects of periodontal/periimplant disease, and qualitative changes in the composition of these biomarkers could have diagnostic value by identifying patients with enhanced disease susceptibility, identifying sites with active disease, predicting sites that will have active disease in the future and/or serving as surrogate end points for monitoring the effectiveness of therapy. Although the diagnostic value of saliva has been recognized for some time (50, 51) and potential biomarkers of periodontal/peri-implant disease have been identified in saliva (39, 67, 74), most work carried out to date has failed to provide reliable aids to the clinician. However, the availability of more sophisticated analytic techniques give cause for optimism that saliva will eventually become the tool needed for more precise treatment planning.