“What happens if antibiotics don't work for a tooth infection?”

I feel like I should change my name to "Dr. It All Depends." Because it does depend on what type of infection you're experiencing. If it is a severely infected tooth that needs definitive treatment like extraction or root canal, then the antibiotics will not clear up the infection until the cause of the infection is addressed. If it is infection following an extraction or root canal, then different antibiotics may be needed or new treatment such as more oral surgery.

Dr. Conrad (Dr. IAD):)

Antibiotics by themselves will not correct a dental infection.A dentist will have options to correct dental problem.

If the 1st antibiotic doesn't work, the infection can be cultured to determine a more effective antibiotic for you. Seeking care as soon as you know that the infection is worsening is very important.

Sometimes a dental infection can be a Penecillin resistant bacteria. Amoxicillin is often used to treat an acute dental infection. It takes about 24 hours for an antibiotic to start working and another 24 hours to begin feeling relief. If it persists it is best to reach the doctor who prescribed the antibiotic to consider a different, broader spectrum antibiotic. If facial swelling occurs, especially up under the eye, it is critical to seek immediate care, and if your dentist is unavailable, to visit ER.