This randomized controlled clinical trial aimed to evaluate the effect of different integrated electronic apex locator (EAL) modes on postoperative pain following nonsurgical endodontic retreatment. A total of 144 patients requiring retreatment of mandibular premolar teeth with periapical lesions were randomly assigned to four groups.
In the control group, working length was determined using a conventional electronic apex locator. In the experimental groups, an integrated EAL motor was used with three different modes: apical reverse, apical slow down, and apical stop.
All procedures were performed under standardized conditions. Postoperative pain was assessed using a numeric rating scale (NRS) at 6 and 12 hours and on days 1, 2, 3, 5, and 7 after treatment.
The study aimed to determine whether simultaneous working length control using integrated EAL modes influences postoperative pain compared with conventional working length determination.
Who can participate
Age range
18 Years – 65 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Systemically healthy patients aged between 18 and 65 years
* Patients requiring nonsurgical endodontic retreatment
* Single-rooted, single-canal mandibular premolar teeth
* Diagnosis of asymptomatic apical periodontitis
* Presence of a well-defined periapical radiolucency (PAI \> 4)
* Teeth with previous root canal treatment performed at least 4 years prior
* Root canal fillings extending to at least the apical third without overfilling
Exclusion Criteria:
* Patients with symptoms such as pain, swelling, or sinus tract
* Patients with a history of smoking or alcohol use
* Teeth with open apices or root resorption
* Teeth with intraradicular posts
* Teeth with insufficient coronal tooth structure
* Teeth with perforation, instrument fracture, or overfilled canals
* Teeth with root curvature greater than 30 degrees
* Teeth with periodontal disease or probing depth \>3 mm
* Cases not suitable for single-visit retreatment
* Patients who used analgesics within 12 hours prior to treatment
* Patients who used antibiotics within the last month
* Patients with cognitive impairment or psychological disorders
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Primary Outcome Measure
Timeframe: 6 hours, 12 hours, and days 1, 2, 3, 5, and 7 after treatment