As a diagnostic fluid, saliva offers superiority over serum due to both aninexpensive n noninvasive collection method by specially trained persons and a cost-effective approach for screening of large populations. These noninvasive tests offer advantages over other tests that involve invasive techniques such as sampling of the subgingival flora or taking a blood sample. Collection of saliva offers a reduced risk of infection compared to the collection of serum. Moreover, obtaining saliva samples from infant, disabled or anxious patients, is much easier than obtaining other samples. There is a lot of useful components-changing information in saliva when a person is in sick. Therefore, we define these changing components as “biomarkers”. As better diagnosissaves lives, utilization of biomarkers as early predictors for clinical disease not only contributes to the effective prevention and treatment of diseases, but also enhances the assessment of potential health risk.