Evaluation of Postoperative Pain and Bacterial Load After Hyalone or Calcium Hydroxide Medication in Mandibular First Molars

This randomized controlled clinical trial aims to evaluate the effect of Hyalone hydrogel compared with calcium hydroxide as an intracanal medicament on postoperative pain and bacterial load reduction in mandibular first molars with necrotic pulp and symptomatic apical periodontitis. The rationale for the study is based on the important role of intracanal medicaments in reducing residual microorganisms between treatment appointments. Calcium hydroxide is widely used because of its antimicrobial activity and alkaline pH; however, it has limitations related to its distribution, adherence to canal walls, antimicrobial spectrum, and effectiveness against microorganisms in complex root canal anatomy. Hyaluronic acid hydrogel has demonstrated potential benefits in dentistry, including supporting tissue healing and reducing inflammation and pain, and may therefore represent a promising alternative intracanal medicament. The study will include 28 patients, equally divided into two groups of 14 participants. Patients will be recruited from the Endodontic Department outpatient clinic at the Faculty of Oral and Dental Medicine, Future University in Egypt. Eligible participants will be medically healthy patients aged 20-40 years, with mandibular first molars diagnosed with necrotic pulp and symptomatic apical periodontitis. Teeth should have closed apices, be restorable, be sensitive to percussion, and demonstrate slight widening of the lamina dura radiographically. Patients with systemic diseases, pregnancy or lactation, allergies to study medications, recent use of antibiotics or analgesics, swelling or acute apical abscess, open apices, vital pulp, periodontal mobility, previous root canal treatment, or abnormal/calcified canal anatomy will be excluded. All participants will receive standardized endodontic treatment over two visits. During the first visit, medical and dental histories, clinical examination, radiographic examination, and preoperative pain assessment using t