Antibiotics for Cleaning Teeth After Hip Replacement?

April 1, 2013 6:00 am Last Updated: April 3, 2013 8:50 pm

What should you do if a dentist or dental hygienist says, “I won’t clean your teeth unless you agree to take antibiotics following surgical hip or knee replacement”?

Today, over 1 million hip and knee replacements are done every year in North America. It’s estimated that by the year 2030 this number will escalate to 4 million annually. But should dentists paint every joint-implant patient with the same brush?

The American Academy of Orthopedic Surgeons (ACOS) is adamant about this question. They claim that during the last 20 years, the number of postoperative hip and knee infections has markedly decreased due to the use of antibiotics during surgery and the immediate postoperative period.

Anyone scheduled for these procedures can shout “hallelujah” for this achievement. Infection was the one thing that concerned me in the days following my hip replacement. Postoperative infection is a serious problem requiring long-term antibiotic treatment and sometimes further surgery.

It’s been aptly said that if you are hunting a lion, be sure to kill him. Going after a wounded one is always more hazardous. Similarly, reoperating on an infected joint is never as easy as the initial surgery. So why not use every precaution to prevent this complication? But, as usual, there’s another side to the story.

A report from the Cleveland Clinic states, “We believe the available evidence does not support routine antibiotic prophylaxis before dental procedures in patients who have undergone total joint replacement even though the practice is very common and even though professional societies recommend it in patients at high risk or even in all patients.”

What evidence do they have to back up this statement? Researchers point out that the germ called Staphylococcus aureus is the main culprit in causing postoperative joint infections. But this organism is rarely present in the oral cavity. Moreover, it is also rarely found in the bloodstream following dental procedures.

Rather, it’s the viridans-group streptococci bacteria that are the primary inhabitants of the mouth. These bacteria commonly enter the bloodstream temporarily following dental trauma to the gums. But they only account for a mere 2 percent of postoperative joint infections.

The Cleveland report cites other evidence. In one study, 1,000 patients who had total joint replacement were followed for the next six years. Of this group, 226 underwent dental procedures without receiving antibiotic therapy, and none developed a prosthetic joint infection.

Possibly their best argument is old-fashioned horse sense. Transient, low-grade bacterial invasion of the blood not only occurs with a dental procedure, but also with daily common activities such as chewing, brushing teeth, and flossing. Moreover, this cumulative exposure to transient bacterial invasion of the blood is several times higher than the single exposure patients receive during teeth cleaning.

It’s also good to consider the role played by dental hygiene. I’ve examined thousands of mouths over the years and some people get “zero” for mouth care. They are either too lazy or too busy to brush their teeth after every meal.

Nor have they learned the simple fact that, unless they use Stim-U-Dents or floss, food and bacteria are always left between the teeth. This results in bad breath or sets the stage for dental disease.

So who is right? Unfortunately, there’s no ultimate answer. But this debate reminds me of the time when it was heresy if patients with a floppy heart valve were not given antibiotics before teeth cleaning. The fear was that without antibiotics, bacteria would infect these valves, causing bacterial endocarditis. Now, experts say this precaution is no longer needed.

It would seem prudent to give antibiotics to those who have had previous joint infections, Type 1 diabetes, or inflammatory disease, and those who are immunosuppressed, HIV infected, or have other high-risk conditions.

But to subject those who have always had sound dental hygiene to antibiotics may be using an elephant gun to kill a mouse. Particularly when antibiotics can cause complications and when we are trying to decrease the use of antibiotics to prevent antibiotic resistance.

I called several dental offices. Ninety percent said antibiotics were required for teeth cleaning.

Dr. Gifford-Jones is a medical journalist with a private medical practice in Toronto. His website is He may be contacted at [email protected].