Background:
Many external factors affect the condition of the oral cavity. Among them there are also substances with ability to generate free oxygen radicals. The imbalance between the formation of reactive oxygen species (ROS) and the body's antioxidant capacity is called oxidative stress. Organisms defend against the toxic effects of ROS with the help of the antioxidant system. Saliva is an important biological fluid in dental research and in the oral physiology. There are a lot of advantages of saliva sampling. The presence of dentures, especially large plate dentures and full dentures, can cause a pathological reaction of the body to the presence of a foreign body in various forms.

Aim:
The aim of the study was to evaluate the influence of the prosthetic restorations on the TAC and TOS concentration in the mixed saliva.

Material and methods:
Participants in this study were chosen from the patients of Academic Center of Stomatology in Bytom. Patients who wear complete dentures and removable partial dentures were recruited for this study. Then the saliva was collected by the absorption method. After sample collection the material was immediately centrifuged for 5 minutes at 2000 x g. The samples were then frozen at -80°C until further testing. The concentrations of oxidative stress markers were determined in centrifuged saliva.

Results:
Removable dentures significantly affect the level total oxidant status TOS, which is lower among patients wearing dentures, especially in total dentures users.

Conclusions:
The presence of removable dentures influences the antioxidant status of saliva.