Updated AAOS guidelines found no evidence that routine antibiotic prophylaxis or preoperative dental screening prevents periprosthetic joint infection (PJI) in total hip or knee arthroplasty. The recommendations—developed with orthopedic, dental, and infectious disease experts—include two limited-evidence and three consensus statements. Antibiotics and antiseptic rinses are not routinely indicated, and dental procedures should be timed by invasiveness. Exceptions may apply for high-risk patients, including those immunocompromised or with prior PJIs. With PJI rates of 1%–2% and projected costs nearing $1.85 billion by 2030, the guideline underscores individualized, evidence-based, shared decision-making.