Background and Aim: At present, there are various methods for performing diagnostic tests. Due to the fact that SALIVA is easily available compared to other body fluids, it can be collected from patients in a noninvasive way and there is no risk of cross-infection because of it, so its use has become more common. Also, the analysis of substances in SALIVA can be a reflection of a person's oral and systemic conditions. Despite its advantages as a diagnostic fluid, the lack of sufficient information about the methods of collecting and storing samples prevents the repeated use of SALIVA. In this article, it has been tried to collect the most standard methods of SALIVA collection, required conditions and supplies, and how to maintain, and provide them to users. Material and Methods: In this review article, data were collected by searching articles which were published between year 2000 and 2020 in domestic and foreign journals, using databases such as: PubMed, PubMed Central, Medline, EBSCO, Google Scholar and Embase with keywords: SALIVA, Dry Mouth, Xerostomia, SALIVAry Determination and SALIVA Estimation. Among the relevant authorities, the articles that were cited many times and were more up-to-date, were selected. Conclusion: It seems like using SALIVA in modern diagnostic tests, makes the diagnosis of many diseases easier, faster and more accurate. The standard methods of SALIVA collection in this article can be used as a guide for laboratory-clinical researchs by researchers.

Statement of the Problem: Systemic conditions can affect the SALIVAry glands and oral health. Hypertension induces xerostomia. Because the function of SALIVA is related to its quality and quantity, therefore, any changes in SALIVA can lead to diminished quality of pa-tient’ s life. Purpose: The aim of this study was to determine the relationship between pH and viscosity of cumulative unstimulated SALIVA and hypertension in adults with sustained hypertension. Materials and Method: This cross sectional study took place on patients referred to oral medicine faculty of Shahid Sadoughi University of Medical Science. The patients’ blood pressure was measured and the 135 patients fitting the inclusion criteria participated in the study. Their unstimulated cumulative SALIVA was collected by spitting method and pH of the samples was measured by digital pH-meter set. The viscosity of the samples was measured by comparing the amount of SALIVA displacement in the thistle tube with control fluids at mm/10 seconds. The data was analyzed by SPSS version 20 software and ANOVA tests and Tukey multiple comparison and their nonparametric equivalent (p≤ 0. 005). Results: The results of this study showed that there was a significant relationship between pH and viscosity of unstimulated SALIVA of normotensive and borderline hypertensive pa-tients (p<. 0001and p<. 005, respectively) and between normotensive and stage I hyperten-sive patients (p<. 0001, p<0. 000). Therefore, hypertension had a direct and significant rela-tionship with SALIVA viscosity but a reverse relationship with SALIVA pH. Conclusion: Hypertension can reduce the pH and increase the SALIVAry viscosity in hyper-tensive patients, which subsequently lead to changes in quality and quantity of secreted SALIVA and influence the oral health and quality of the patient’ s life.