The Oral Resistome: A Clinical Review of Antimicrobial Resistance and Stewardship in Dental Practice

Antimicrobial resistance (AMR) is a global crisis, and the oral cavity is increasingly recognized as a significant and often overlooked reservoir of antibiotic resistance genes (ARGs). The "oral resistome" is profoundly shaped by antibiotic prescribing practices in dentistry. This review synthesizes clinical and microbiological evidence on the oral resistome and the status of dental antimicrobial stewardship. The oral microbiome harbors a vast collection of ARGs in both healthy and diseased states. Over 150 unique ARGs conferring resistance to major antibiotic classes, including tetracyclines, macrolides, and beta-lactams, are widespread in oral biofilms and saliva. Dental practitioners contribute significantly to this selective pressure, as they prescribe 3–11% of all antibiotics used in human healthcare. In many settings, 50–90% of these prescriptions are unnecessary or non-guideline-concordant, driven by diagnostic uncertainty, patient pressure, and systemic barriers to treatment. This overprescribing drives the selection of clinically relevant resistant organisms, such as beta-lactamase-producing Prevotella species in odontogenic abscesses and multi-drug resistant pathogens such as Enterococcus faecalis and Methicillin-resistant Staphylococcus aureus (MRSA) in refractory endodontic and peri-implant infections. A critical data gap exists regarding both resistome composition and prescribing habits in low- and middle-income countries (LMICs), including the Middle East and North Africa (MENA) region, where over-the-counter access to antibiotics often exacerbates the problem. Effective antimicrobial stewardship (AMS), particularly interventions such as audits and feedback, is urgently needed but is sparsely implemented. Integrating dental AMS into national AMR action plans is a global public health imperative for preserving antibiotic efficacy.