en عمومى General پژوهشي Research Introduction and objectives: Oxidative stress plays a crucial role in the onset and also the progression of vascular and neurological complications of diabetes. The present study was aimed to determine and compare the antioxidant capacity of saliva in patients with type 1 diabetes compared with those do not have diabetic.<br> Materials and methods: In this case-control study, the patients aged 20-40 years referred to Imam Khomeini Hospital in Ardabil were categorized into two groups including 30 patients with type 1 diabetes as a case group and 30 non-diabetics as a control group. These two groups were compared in terms of TAC levels in saliva. The TAC of saliva the patients measured by 2,2&prime;-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) method. The analysis of data was carried out through t-test statistic using &quot;SPSS Statistics Version 24&quot; at a significant level of P <0.05.<br> Results: Based on the data achieved from the present study, the mean and standard deviation of TAC of saliva in patients with type 1 diabetes was 0.380 &plusmn; 0.120 (&mu;mol / l) and in non-diabetics was 0.306 &plusmn; 0.122 (&mu;mol / l). The increment of TAC of saliva in the case group compared to the control group was significant based on T-test (p = 0.003).<br> Conclusion: Since there is a significant increment in the level of TAC of saliva in patients with type 1 diabetes compared to non-diabetics, the determination of the level of TAC of saliva in patients with type 1 diabetic can be used as an alternative method for early diagnosis of diabetes.<br> &nbsp; Diabetes, Antioxidants, Oxidative stress, Saliva, Total antioxidant capacity (TAC) of saliva 183 190 http://intjmi.com/browse.php?a_code=A-10-1-474&slc_lang=en&sid=1 Hamed Zandian 10031947532846005120 0000000212845823 Yes –Social Determinants Of Health Research Center, Ardabil University Of Medical Sciences, Ardabil, Iran Abnoos Mokhtari Ardekani 10031947532846005121 10031947532846005121 No Endocrinology And Metabolism Research Center, Institute Of Basic And Clinical Physiology Science, & Physiology  Research Center, Kerman University Of Medical Sciences, Kerman, I.R. Iran Ulduz Zamaniahari 10031947532846005122 10031947532846005122 No Department Of Oral Medicine , School Of Dentistry , Ardabil University Of Medical Sciences , Ardabil , Iran