Inclusion Criteria:  all patients were systemically healthy stage III-IV grade B periodontitis A minimum of two non-adjacent teeth having sites with ≥ 5 mm interdental clinical attachment loss . Radiographic bone loss extending to middle third of root and beyond . All patients were heavy smokers i.e ≥ 20 cigarettes / day .  Exclusion Criteria:  patients who had received any periodontal or antibiotic treatment or vitamins supplementation during the last six months. pregnant or lactating women patients who refused to provide written informed consent