Assessment of Postoperative Pain and Antibacterial Efficacy After Root Canal Irrigation With Curcumin Versus Sodium Hypochlorite in Patients With Necrotic Mandibular Molars: Randomized Clinical Trial

patients with necrotic mandibular molars will be selected

1. Diagnostic procedures:

• Personal information (name, age, gender, address and phone number), full medical and dental histories using schematic charts will be obtained from all patients participating in this research.
• History of chief complaint will be obtained in the dental history chart.
• Clinical and radiographic evaluation for each tooth included in this study will be recorded. The tooth will be examined for presence of extensive caries or pulp exposures. Soft tissue examination and tooth mobility evaluation will be done by percussion and palpation.
• Extraoral examination will be performed by visual inspection of the face and neck and palpation for any swollen lymph nodes.
• Each tooth will be evaluated for sensitivity using electric pulp tester. Diagnosis will also be confirmed by the absence of bleeding after access cavity preparation.
• Final Diagnosis: Mature mandibular asymptomatic necrotic molars with normal periapical radiographic appearance.
• The operator will explicitly explain the trial steps to the patients, and an informed consent will be signed by patients who accept enrollment.
• Pain scale chart will be given to each patient to rate his /her pain level before endodontic treatment as preoperative reading using a Numerical Rating Scale (NRS).

2. Endodontic procedures:

• All the performed steps of root canal treatment will be included in the chart of endodontic procedures.
• The tooth will be isolated with rubber dam to maintain aseptic field, after isolation the tooth and surrounding field will be disinfected by a protocol using 3% hydrogen peroxide and 2.5% sodium hypochlorite before and after coronal access cavity preparation.
• The initial sample S1 will be collected from root canals before preparation using sterile paper points. Each root canal will be dried with 3 sterile paper points ISO# 15 which will be left inside the root canal for 1 minute each with pumping movements to generate a suspension with bacteria of the main pulpal area.
• The paper points will be immediately placed in sterile test tubes containing reduced transport medium of thioglycolate and sent to the Microbiology Laboratory, Faculty of Medicine, Cairo University for microbiologic processing to be cultured within one hour.
• Root canals will be mechanically prepared in a crown-down approach using ProTaper Universal NiTi files in an X-Smart endodontic motor according to the manufacture instructions.
• The canals will be thoroughly irrigated between every two subsequent files using 2 ml of 2.5% NaOCl using a side vented needle (gauge 29) to control the possibility of irrigant apical extrusion.
• After complete root canal preparation all canals will be flushed with 17 % EDTA followed by sterile saline.

3. Random allocation:

• According to the randomization sequence, after complete root canal preparation patients will be assigned to one of 2 groups: