This study is being conducted to find out which of two medications-Chlorhexidine Gel or Nitrofurantoin-works better in reducing pain between root canal treatment visits. Sometimes, patients with infected teeth (called symptomatic apical periodontitis) continue to feel pain between treatment appointments. To help with this, dentists use medications inside the cleaned tooth canal.

In this trial, 220 patients will be divided into two groups. One group will receive Chlorhexidine Gel, and the other will receive Nitrofurantoin paste inside their tooth during the first treatment visit. Pain levels will be recorded before treatment, and again after 24 and 48 hours using a pain scale from 0 (no pain) to 10 (severe pain). No pain medicine will be given unless the patient feels very uncomfortable.

The study is taking place at the Altamash Institute of Dental Medicine in Karachi, and will help dentists understand which medication helps patients feel better faster during root canal treatment.

This randomized controlled trial is designed to evaluate and compare the efficacy of two commonly used intracanal medicaments-2% Chlorhexidine Gel and Single Antibiotic Paste (Nitrofurantoin)-in reducing inter-appointment pain during root canal treatment of teeth diagnosed with symptomatic apical periodontitis.

Pain between root canal visits is a common concern. The persistence of microbial infection within the root canal system can lead to inflammation of the peri-radicular tissues, causing discomfort. Intracanal medicaments are placed after chemo-mechanical preparation to enhance disinfection, reduce microbial load, and minimize postoperative complications such as pain.

While Chlorhexidine has long been used due to its broad-spectrum antimicrobial activity and substantivity, Nitrofurantoin, a nitrofuran antibiotic, has shown promising results against resistant organisms and may offer similar or enhanced pain relief when used as a local medicament.

A total of 220 patients, aged 16 to 45 years, presenting with single-rooted permanent teeth requiring primary root canal treatment and diagnosed with pulp necrosis and symptomatic apical periodontitis, will be enrolled at the Department of Operative Dentistry and Endodontics, Altamash Institute of Dental Medicine, Karachi. Patients will be randomly allocated into two equal groups (n=110 per group) using the lottery method.

Group 1 will receive Chlorhexidine Gel as the intracanal medicament.

Group 2 will receive Nitrofurantoin Paste, prepared by mixing crushed Nitrofurantoin tablets with saline.

Pain intensity will be measured using the Visual Analogue Scale (VAS) at three time points: preoperatively, 24 hours, and 48 hours after the first treatment visit. Inter-appointment pain reduction will be calculated using the formula:

[(Pre-treatment VAS score - Post-treatment VAS score) / Pre-treatment VAS score] × 100

Standardized root canal procedures, including anesthesia, canal preparation, irrigation, medicament placement, and obturation, will be performed by a single postgraduate trainee to ensure consistency. No analgesics will be prescribed unless requested by the patient due to severe discomfort. If needed, ibuprofen 200 mg will be provided and documented.

Data will be analyzed using SPSS version 20. Continuous variables (e.g., pain scores) will be assessed for normality. Depending on distribution, t-tests or non-parametric equivalents will be used to compare groups. Stratification will be done for potential confounders such as age, gender, and type of tooth. A p-value < 0.05 will be considered statistically significant.

The study's goal is to provide evidence on whether Nitrofurantoin is more effective than Chlorhexidine Gel in reducing pain between appointments, potentially offering a new and effective intracanal medicament option in endodontic practice.

Inclusion Criteria:

• Patients with single rooted permanent teeth of both arches.
• Patients with a pulpal status of necrosis with or without periapical radiolucency, confirmed using Electric Pulp Test (EPT) and Cold Test.
• Male and female patients age of 16 to 45 yrs.
• Patients of both genders.

Exclusion Criteria:

• Patients with uncontrolled diabetes.
• Presence of periapical granuloma or cyst confirmed via radiographic evaluation.
• Patient is on any medication that affects pain, inflammation and infection like analgesic, antibiotics since last 7 days
• Patient requiring endodontic re-treatment.
• Patients with immature teeth with open apices.
• Patients with calcified canals.