And here's where it gets complicated: Revised state guidelines tell dentists they can now perform nonemergency work -- but they can't "generate aerosols." In other words, nothing that might send patients' saliva out of their mouths and into the air.
The exception: " ... as a last resort when clinically necessary," according to Pennsylvania guidelines.
But in dentistry, aerosolization is virtually unavoidable.
"If there's a patient in the chair and you do anything that gags them or they have allergies and they cough in your chair, there can be aerosols that can be produced even if you are not using a drill or an ultrasonic cleaner," said dentist Michael Barnes, who owns a practice in South Philadelphia.
Lisa Maisonet, a hygienist who helps run 22 Philadelphia-area dental practices, put it bluntly: "Everything we do creates aerosols. Everything," she said. "It's like the state said, 'Here's a swimming pool, jump in, but please don't get wet.'"
Adding to the confusion, the Health Department says dentists should "apply their clinical judgment" when deciding what is safe. They should go ahead with treatment if not doing so would cause "irreversible damage to the patient."
Barnes said some of the Health Department guidelines directly contradict other parts. That creates a heavy burden on dentists to determine the right thing to do in uncharted terrain.
For now, he's decided not to perform routine cleanings, deeming them too risky. But he would use a drill, which can create aerosols, for "a few seconds" to smooth "a sharp edge of a broken tooth that is cutting into the patient's tongue or cheek," as long as he's wearing adequate personal protective equipment, he said.
"I do have concerns that some dentists may swing too far in either direction," Barnes said. "Some may try to get back to normal volume too quickly and risk the spread of the virus. Others may be too conservative and risk leaving their patients with difficulty in accessing urgent dental care."
The vast majority of dentists in Pennsylvania and New Jersey work in privately owned solo or group practices. They remain both medical provider and small-business owner -- a dual identity that requires them to consider the health of their employees and patients, as well as the health of their business.