Human diseases having global impact include cancer, cardiovascular, metabolic, and neurological diseases. Diagnosing these disease conditions is becoming challenging and thus requires supplementing clinical evaluation with laboratory testing . Salivary diagnostics holds great promise as an effective modality for the early diagnosis, prognostication, and monitoring posttherapy status. Whole saliva is a mixture of the secretions of the major and minor salivary glands, mucosal transudations, gingival crevicular fluid, serum and blood derivatives from oral wounds, desquamated epithelial cells, expectorated bronchial and nasal secretions, bacteria and bacterial products, viruses and fungi,other cellular components, and food debris. It is a complex fluid containing an entire library of hormones, proteins, enzymes, antibodies, antimicrobial constituents, and cytokines . The mechanism of entry of these constituents from the blood into the saliva is by transcellular, passive intracellular diffusion and active transport, or paracellular routes by extracellular ultrafiltration within the salivary glands or through the gingival crevice . The many advantages of saliva as a clinical tool over serum and tissues are noninvasive collection of sample, smaller sample aliquots, good cooperation with patients, cost effectiveness, easy storage and transportation, greater sensitivity, and correlation with levels in blood.