The primary objective of this randomized clinical trial is to evaluate and compare the effectiveness of two natural, herbal-based intracanal medications-Propolis and Green Tea Polyphenolics (EGCG)-against the conventional Calcium Hydroxide in reducing postoperative pain and the incidence of flare-ups during non-surgical root canal retreatment.

Postoperative pain is a common complication in endodontics, particularly in retreatment cases where complex bacterial environments and procedural challenges increase the risk of discomfort and acute flare-ups. While Calcium Hydroxide is the traditional gold standard due to its antimicrobial properties, natural phytotherapeutics like Propolis and Green Tea are being investigated for their potent anti-inflammatory, antioxidant, and antibacterial benefits, which may offer superior biocompatibility and symptomatic relief.

Forty patients requiring endodontic retreatment of single-rooted teeth will be randomly assigned to one of three groups:

Group I (Control): Receives Calcium Hydroxide paste.

Group II: Receives Propolis-based medication.

Group III: Receives Green Tea Polyphenolic-based medication.

The study follows a two-visit protocol. During the first visit, the previous root canal filling is removed, the canal is cleaned and shaped, and the assigned medication is placed. Postoperative pain will be assessed using a Visual Analog Scale (VAS) at 6, 12, 24, 48, 72 hours, and 7 days. Flare-up incidence (sudden severe pain or swelling) will also be monitored. In the second visit, the medication is removed, and the canal is permanently sealed using a bioceramic sealer and gutta-percha. The results will help determine if these herbal alternatives can provide a more comfortable treatment experience for patients undergoing root canal retreatment.

Inclusion Criteria:

• Failed previously performed endodontic treatment of single-rooted teeth.
• Presence of a periapical lesion ranging from 1 mm to 2 mm in diameter.
• Teeth with complete root formation.
• Teeth without evidence of external or internal root resorption.

Exclusion Criteria:

• Pregnant females.
• Patients with uncontrolled systemic diseases.
• Patients currently under antibiotic or analgesic administration.
• Patients presenting with facial swelling.
• Teeth not indicated for endodontic retreatment (e.g., poor oral hygiene, mobile teeth, or recessed teeth).

Individual Participant Data (IPD) will not be shared due to privacy concerns and the limited scope of data use approved by the ethics committee. The study is designed for internal analysis only and does not include provisions for public data sharing