Bacterial Profiles in Primary Apical Periodontitis Using 16S rRNA PCR

This pilot randomized clinical study aims to compare bacterial profiles in symptomatic and asymptomatic primary apical periodontitis using 16S rRNA polymerase chain reaction sequencing. Twenty-four mandibular first molars requiring endodontic treatment will be selected from patients attending the Conservative Dentistry Clinic at the Dental and Oral Hospital of Hasanuddin University. The samples will be divided into two diagnostic groups: symptomatic primary apical periodontitis and asymptomatic primary apical periodontitis. Each diagnostic group will then be allocated into two irrigation groups using either 3% or 5.25% sodium hypochlorite. Microbial samples will be collected from the distal root canal at three time points: before root canal treatment, after chemomechanical preparation and sodium hypochlorite irrigation with ultrasonic activation, and two weeks after intracanal calcium hydroxide medication. Root canal samples will be subjected to bacterial DNA extraction, 16S rRNA PCR amplification, sequencing, and taxonomic identification. The primary outcome is the presence or absence of detectable bacterial DNA at each sampling stage. Secondary outcomes include the bacterial taxa identified in symptomatic and asymptomatic primary apical periodontitis and changes in bacterial profiles after sodium hypochlorite irrigation and calcium hydroxide medication. The study is designed to provide preliminary clinical-molecular evidence on bacterial profile changes during endodontic treatment of primary apical periodontitis.

Inclusion Criteria: * Adult patients who are mentally and physically healthy, aged 18-40 years. Mature permanent molar teeth diagnosed with symptomatic or asymptomatic apical periodontitis, determined based on: Patient history; Intraoral clinical examination; For symptomatic apical periodontitis: negative pulp vitality test, negative palpation test, positive percussion test, with or without widening of the periodontal ligament space; For asymptomatic apical periodontitis: negative pulp vitality test, negative palpation test, percussion test findings, and radiographic assessment using a periapical index score of less than 5 based on periapical radiographs. Teeth with straight root canals. Teeth that are restorable after root canal treatment. Patients who are willing to participate in the study and have signed the informed consent form after receiving an explanation of the study. Exclusion Criteria: * Participants will be excluded if the tooth or patient presents with any of the following conditions: Patients who have taken antibiotics within 7 days before sample collection. Advanced tooth mobility greater than grade 2. Periodontal pockets greater than 4 mm. Teeth with previous endodontic treatment. Root fracture or fracture occurring during root canal treatment. Teeth showing internal or external resorption. Teeth with open apices. Teeth with calcified or obliterated root canals. Patients with systemically compromised conditions requiring antibiotic coverage for routine dental treatment or patients with systemic diseases.