Tissue Plasminogen Activator and Plasminogen Activator Inhibitor Type-1 Gene Expression will be evaluated clinically and histopathologically through Hematoxylin and eosin as well as by quantitative reverse transcription polymerase chain reaction in the gingival tissues of chronic periodontitis in an attempt to investigate whether the expression of these proteins could be involved in the disease pathogenesis or not, and to assess as well if their expression will be affected by the applied surgical periodontal treatment.

30 subjects were enrolled in this study and divided into: Group I (Control Group): 10 periodontally healthy volunteers, Group II (Chronic Periodontitis Group): 20 patients suffering severe CP and Group III (Treated Group): 20 patients who were scheduled for OFD. Gingival samples were collected from all subjects at baseline and at 3 months after OFD from the CP patients. Then, Hematoxylin and eosin (H&E) stained slides were examined and gene expression levels of t-PA and PAI-1 were measured in the gingiva through quantitative reverse transcription polymerase chain reaction (RT-PCR).

Inclusion Criteria:

• Patients with severe chronic periodontitis
• Pocket depth (PD) of ≥5 mm
• Clinical attachment level (CAL) ≥5 mm

Exclusion Criteria:

• Pregnant women
• Subjects taking any type of medication and/or antibiotic therapy during the 3 months before the study
• Subjects who received periodontal treatment within the past 6 months
• Smokers

Study population includes 30 subjects recruited from the outpatient clinic of Oral Medicine & Periodontology department, Faculty of Dentistry, Cairo University. Ages range from 30-50 years old.