Background: Diabetes mellitus is quite prevalent and causes many complications in different parts of the body. It also affects the quality of life by causing many complications in the oral cavity. This study examined a simple intervention to improve oral and periodontal tissue health and investigate its effect on the patient›s salivary characteristics and blood sugar control. Methods: This double-blind clinical trial was performed on 40 patients with type 2 diabetes. Fasting blood sugar (FBS), glycated hemoglobin (HbA1C), salivary glucose, amylase, total protein, viscosity, and pH were evaluated before and after scaling and oral hygiene instructions. The obtained data were entered into SPSS 17 statistical software and analyzed using the t-test, MannWhitney, and chi-square tests. Results: After the intervention, the FBS results in both groups (P value=0.015 in the case group and P value=0.017 in the control group) and HbA1C in the case group (P value=0.006) decreased significantly. Also, the difference in salivary viscosity, pH, and glucose between the case group and the control group was significant (P value=0.005, 0.008, and 0.021, respectively). Conclusion: Based on the results of the present study, scaling, and oral hygiene instructions reduce FBS and HbA1C, salivary glucose and amylase and oral conditions, leading to good blood sugar control.