[SYLWAN., 163(11)]. ISI Indexed 236 Article The effect of irrigating solutions on postoperative pain and intensity of bacteremia following single visit root canal treatment Eyad A. Elbattawy 1 , Jealan M. El-Shafei 2 , Nayra Mehanna 1 , Geraldine M. Ahmed 2 , Ahmed Ghareeb 3* and Karim Montasser 4* 1 National Research Center, Cairo, Egypt; Eyadelbatawi@hotmail.com (E.E), Mehanna2006@hotmail.com (N.M) 2 Endodontic department Faculty of Oral and Dental Medicine, Cairo University, Egypt; dr_jealan@yahoo.com (J.E), Geraldine.ahmed@dentistry.cu.edu.eg (G.A) 3 Microbiology department, faculty of science, Cairo University, Egypt; ahmed.ghareeb@med.asu.edu.eg (A.G) 4 Department of Clinical Pathology Faculty of Medicine, Helwan University, Cairo, Egypt; karim.montasser@med.helwan.edu.eg (K.M) * Correspondence: ahmed.ghareeb@med.asu.edu.eg (A.G); Eyadelbatawi@hotmail.com(E.E), Tel.: +20-10-638-11225 (A.G); Tel.: +20-10-613-88884 (E.E) Abstract: Infective endocarditis might occur due to the colonization of microorganisms on the endothelial surface of the heart. This characteristic vegetation consists of amorphous masses of platelets and fibrin with microorganisms and inflammatory cells. Until now, Infective endocarditis is still responsible for high rates of mortality and morbidity. Therefore susceptible patients should be evaluated for antibiotic prophylaxis whenever they undergo any dental procedures that might cause bacteremia as root canal therapy. If bacteremia occurs, root canal treatment might increase the risk of infective endocarditis occurrences in patients with predisposing valvular diseases. Elimination of intracanal bacterial flora is crucial for healing following root canal therapy. Some antibacterial and chelating substances have been suggested to clean and shape root canals. The present clinical study aimed to evaluate postoperative pain, evaluate bacterial reduction from the root canals and assess the intensity of bacteremia after chemomechanical preparation using three types of irrigation protocols (MTAD irrigation protocol, NaOCl irrigation protocol, Saline as a positive control group). A total of 60 medically free patients of both sexes with single necrotic canals were selected for this study. Patients were classified into three groups. The first group was treated with sodium hypochlorite (1.3% followed by MTAD for minutes, the second group was treated with NaOCL (5.25%) and 17 % EDTA for 1 minute, while the third group was treated with saline then treatment was completed as in the second group. The difference between the groups was not statistically significant.