By Saumya Joseph

(Reuters Health) – More than three-quarters of antibiotic prescriptions written by dentists before dental procedures are unnecessary and might do more harm than good, a new U.S. study found.

Dentists write one of every ten antibiotic prescriptions in the United States, and despite national declines, antibiotic prescribing by dentists has held steady over the years, researchers wrote.

Dentists need to be included in the public health conversation regarding appropriate antibiotic use and antimicrobial resistance, lead author Katie Suda of the University of Illinois, Chicago, told Reuters Health by phone.

Antibiotics before dental procedures are recommended for a small subset of patients with certain medical conditions, to prevent a serious heart infection that might arise from the release of oral bacteria into the bloodstream during the procedures. The infection, endocarditis, is an inflammation of the lining of the heart’s chambers and valves.

To see if antibiotics are being prescribed for dental patients according to established guidelines, Suda and her team used an insurance database to analyze prescriptions written during 168,000 dental visits from 2011 to 2015.

They found that 80.9% of prescriptions for antibiotics to be taken before procedures were unnecessary.

Among the 91,438 patients in the study, only 20.9% had a cardiac condition that put them at the highest risk of developing endocarditis and warranted an antibiotic prescription.

Patients with artificial joint implants had more than double the odds of receiving unnecessary antibiotic prescriptions compared with patients who did not have the implants. This is despite the fact that the American Academy of Orthopaedic Surgeons and the American Dental Association now say people with prosthetic joint devices do not need antibiotics before dental procedures.

In particular, the antibiotic clindamycin was highly likely to be unnecessarily prescribed. Clindamycin has been linked with a severe form of diarrhea known as Clostridium difficile (C. diff). A single dose of clindamycin carries the same risk of C. diff infection as a prolonged course of the antibiotic, the researchers wrote, making it all the more alarming that clindamycin was among the overused antibiotics.

Misuse and overuse of antibiotics encourages bacteria to evolve and find ways to resist the medicines. The World Health Organization has called antibiotic resistance a global health emergency.

Why is there so much over-prescribing by dentists? Experts say dentists may face pressure from patients or patients’ cardiologists and orthopedic surgeons, who insist on antibiotics.

“Dentists feel like they are in a really tough position,” said Dr. Emily Spivak of the University of Utah School of Medicine, who wrote an editorial that was published with the study.

“They’re not physicians and they feel like they have to give (antibiotics) because they will be held accountable from the surgeon or the cardiologist if the patient gets an infection,” she told Reuters Health.

Other factors driving unnecessary prescribing may include dentists’ lack of awareness of the most recent guidelines, lack of agreement with these guidelines and the practice of ‘defensive medicine,’ experts said.

Spivak, however, believes the current study may over-inflate the numbers as it includes only commercially insured patients.

The ‘worried well’ or those who suffer from health anxiety may be driving some of this prescribing, she added.

Experts say patients should feel empowered to ask questions when their dentists prescribe antibiotics, and they shouldn’t pressure dentists to provide them with the drugs.

“An informed patient who asks questions can allow for a discussion between the dentist and the patient to truly understand whether they need an antibiotic,” Dr. Salim Virani of the Baylor College of Medicine, told Reuters Health by email.

SOURCE: and JAMA Network Open, online May 31, 2019