Medical and dental history will be obtained from all patients participating in this trial. Clinical and radiographic evaluation for each tooth included in this study will be recorded.~Clinical diagnosis of symptomatic apical periodontitis is to be confirmed.~After single-visit root canal treatment, eligible participants will be randomly assigned to one of the following groups: experimental group (taking oral tablet 1000 mg of Amoxicillin/ clavulanic acid combination) or control group (taking placebo tablet).~Each patient will receive a 7-day diary to record postoperative pain and swelling.In case of pain, the participant will be instructed to take an analgesic. Post-operative pain will be measured as a primary outcome on 11-point scale (NRS) at the following time points: 6, 12, 24, 48, 72 hours and 7 days. The occurrence of swelling will be reported by participant as a secondary outcome.
The aim of this prospective, randomized, placebo controlled study is to evaluate the effect of amoxicillin/clavulanic acid combination on post-operative pain and swelling in adult patient with symptomatic apical periodontitis.