Abstract
CONTEXT: Antimicrobial resistance represents a global health crisis, with the oral microbiome serving as a significant reservoir for resistance genes. Despite guidelines discouraging antibiotic use for irreversible pulpitis, empirical prescription remains common in endodontic practice. This study aimed to evaluate the prevalence of β-lactam and tetracycline resistance genes in acute and chronic irreversible pulpitis. SUBJECTS AND METHODS: Pulp tissue samples were collected from 24 patients (12 acute and 12 chronic irreversible pulpitis) meeting strict inclusion criteria. Following DNA extraction, polymerase chain reaction amplification was performed to detect tetracycline resistance determinants (tetA and tetB) and β-lactamase genes (blaTEM and blaCTX). Amplicons were analyzed by gel electrophoresis. RESULTS: Antibiotic resistance genes were detected in 54.2% of samples, with higher prevalence in acute (66.7%) versus chronic pulpitis (41.7%). The blaTEM gene was detected in 25.0% of samples from both acute and chronic cases, while tetA was more prevalent in acute (41.7%) than chronic pulpitis (16.7%). Co-occurrence of both resistance genes was observed exclusively in acute pulpitis (25.0%, P = 0.043). Sequence analysis confirmed the functionality of detected resistance genes with >98% homology to reference sequences. CONCLUSION: The present analysis demonstrates the concerning prevalence of antibiotic resistance genes in pulpal infections, particularly in acute irreversible pulpitis. The higher prevalence of tetA and co-occurrence of multiple resistance genes in acute cases provide molecular evidence supporting clinical guidelines against routine antibiotic prescriptions for irreversible pulpitis. The findings reinforce the significance of implementing robust antibiotic stewardship protocols within endodontic practice and underscore the imperative for continuous surveillance of antimicrobial resistance patterns.