The aim of the research will be to evaluate the effects of NSPT on clinical periodontal parameters, level of antioxidants in unstimulated saliva and the levels of biomarkers (VEGF, TGF-β, IL-17) in the GCF in SSc patients in comparison with systemically healthy controls. Twenty systemic sclerosis patients with periodontitis (SS group) and twenty systemically healthy periodontitis patients (P group) will be enrolled in the present study. The results may indicate higher periodontal destruction and antioxidant perturbations in unstimulated saliva of systemic sclerosis patients with periodontitis compared to systemically healthy periodontitis patients.