Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 12 3 2015 10 12 200 205 EN Farnaz Hajifattahi Assistant Professor, Department of Oral Medicine, Dental Branch Islamic Azad University, Tehran, Iran Maryam Hesari Dentist, General Practitioner, Tehran, Iran Homayoun Zojaji Associate Professor, Department of Gastroenterology, Shahid Beheshty University of Medical Sciences, Tehran, Iran Fatemeh Sarlati Associate Professor, Department of Periodontics, Dental Branch Islamic Azad University, Tehran, Iran 2015 10 11 2015 10 11 Objectives: Gastric infection with Helicobacter pylori may be one of the main causes of halitosis. This study was performed to evaluate the relationship of Heli- cobacter pylori infection with halitosis. Materials and Methods: This case control study was performed on 44 dyspeptic patients with a mean age of 34.29±13.71 years (range 17 to 76 years). The case group included 22 patients with halitosis and no signs of diabetes mellitus, renal or liver failure, upper respiratory tract infection, malignancies, deep carious teeth, severe  periodontitis,  coated  tongue,  dry  mouth  or poor  oral  hygiene.  Control group included 22 patients without halitosis and the same age, sex, systemic and oral conditions as the case group. Halitosis was evaluated using organoleptic test (OLT) and Helicobacter pylori infection was evaluated by Rapid Urease Test (RUT) during endoscopy. The data were statistically analyzed using chi square, Mann Whitney and t-tests. Results: Helicobacter pylori infection was detected in 20 (91%) out of 22 halitosis patients, and 7 control subjects (32%) (P<0.001). Conclusion: Helicobacter pylori gastric infection can be a cause of bad breath. Dentists should pay more attention to this infection and refer these patients to in- ternists to prevent further gastrointestinal (GI) complications and probable malig- nancies. https://fid.tums.ac.ir/index.php/fid/article/view/287 https://fid.tums.ac.ir/index.php/fid/article/download/287/272