Numerous studies investigating oxidative stress in saliva in relation to dental caries and dental treatment focus on parameters such as total antioxidant capacity and malondialdehyde. This study is the first to utilize 8-isoprostane as a salivary biomarker to assess oxidative stress in relation to both caries and dental treatment. Salivary properties are also evaluated. The innovation of this study lies in its unique approach: although these salivary parameters have been examined individually in past research, this is the first study to evaluate them in conjunction with oxidative stress. A total of 26 children with caries and 20 caries-free children aged between 4 and 12 years old were included in this study. From both groups, stimulated saliva was collected and used to assess salivary properties and the 8-isoprostane level. For the caries group, the same measurements were also conducted after dental treatment. Children with caries had significantly lower levels of pH, and conductivity compared to caries-free children. The concentration of 8-isoprostane did not differ significantly between the two groups. In the caries group, dental treatment led to an increase in salivary conductivity and buffer capacity, along with a decrease in 8-isoprostane levels
