Zaric 2009.

Methods	Randomized clinical trial
Participants	Country: Serbia Sample size: 66 individuals were selected in this study, but only 43 patients were included for this review. 43 patients with both gastric and oral H. pylori infection, all patients with periodontitis (intervention, 21; control, 22). Sex (M/F): 29/37 Age: 19 to 78 years H. pylori testing: PCR Oral H. pylori status: H. pylori positive
Interventions	Intervention group: H. pylori eradication and periodontal treatment for 7 days Control group: H. pylori eradication for 7 days only H. pylori eradication: amoxicillin 2.0 g, clarithromycin 1.0 g, pantoprazole 80 mg, once a day for 7 days Periodontal treatment: oral hygiene orientation, ultrasonic scaling and root planing for removing plaque and calculus, irrigation of periodontal pockets with 0.12% chlorhexidine‐gluconate (during triple therapy)
Outcomes	Eradication rate of gastric H. pylori eradication rates (3 months after eradication)
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Block randomization method was performed for treatment allocations (author correspondence)
Allocation concealment (selection bias)	Unclear risk	Not described in article
Blinding (performance bias and detection bias) All outcomes	Low risk	Single blind (blinding of outcome assessment): the examiner who was responsible for H. pylori detection was blinded
Incomplete outcome data (attrition bias) All outcomes	High risk	From both groups, a number of patients did not complete the study due to different reasons, but the authors did not report the exact number or the reasons (author correspondence).
Selective reporting (reporting bias)	Low risk	All pre‐defined outcomes were reported
Other bias	Low risk	—

ITT: intention‐to‐treat; PCR: polymerase chain reaction; PPI: proton pump inhibitor.