Purpose: The purpose of this randomized controlled trial was to compare the surgical site infection rate with short (24 hours) vs extended (7 days) antibiotic prophylaxis for maxillary sinus floor augmentation surgery.

Materials and methods: Eighty-five patients who were candidates for unilateral or bilateral maxillary sinus floor augmentation surgery were randomly assigned to short or extended antibiotic prophylaxis. Patients were evaluated on days 7, 14, 30, 60, and 180 after surgery for symptoms and signs of infection. The primary study endpoint was the development of surgical site infection up to day 180 postoperatively.

Results: Patients underwent a total of 117 maxillary sinus floor augmentation surgeries, 62 in the short prophylaxis arm and 55 in the extended prophylaxis arm. Fifty-three patients (62%) had unilateral surgery, and 32 (38%) had bilateral surgery. Three patients developed a surgical site infection by 180 days postsurgery (overall rate, 2.6%): one patient (1.6%) in the 24-hour arm and two (3.6%) in the extended prophylaxis arm. All three patients received antibiotic treatment, and the infections resolved entirely.

Conclusion: A low rate of surgical site infection was observed after maxillary sinus floor augmentation, and there was no apparent advantage to extended (7 days) vs short (24 hours) duration of antibiotic prophylaxis. The findings do not support the use of extended postprocedural chemoprophylaxis for patients undergoing maxillary sinus floor augmentation.