So, you’ve just finished suturing an uncomplicated laceration and you think to yourself: should I apply antibiotic ointment or just cover with a bandage with good return precautions?
Answer: There is some limited evidence to support antibiotic ointment use.
A study by Dire et al. in 1995 enrolled 465 patients with uncomplicated ED lacerations (including those that had absorbable subcutaneous sutures) to antibiotic ointment or petrolatum ointment with application 3times a day until patients returned for suture removal. The risk of infection of those treated with antibiotic ointment was 4.5-5.5% (depending on the type of antibiotic ointment) vs. 17.6% in those with petrolatum. This gives you a NNT of ~8.
Anna L. Waterbrook et. al. “Do Topical Antibiotics Help Prevent Infection in Minor Traumatic Uncomplicated Soft Tissue Wounds?”. Ann Emerg Medicine. 2013; 61: 86-88.
Dire DJ, Coppola M, Dwyer DA, et al. Prospective evaluation of topical antibiotics for preventing infections in uncomplicated soft-tissue wounds repaired in the ED. Acad Emerg Med. 1995; 2:4-10