The precise relationship between dental hygiene and cardiac health has long been a subject of medical debate. While people with cleaner mouths tend to have healthier hearts, does the first influence the second — or are both the result of general tendencies to be healthy (or unhealthy)?

Now, an American Heart Association study has added new fuel to the argument for a direct link.

Lead researcher Shogo Matsui states in the conclusion of the study that “decreased frequency and duration of tooth brushing is associated with higher risk of cardiovascular events.”

The study evaluated 682 people’s tooth-brushing habits; adjusted for several factors (such as age, sex, and cardiovascular risk); and determined that those who brushed less than twice a day for less than two minutes each time were at three times the risk of dangerous heart events.

Poor dental habits can lead to periodontal disease, which the National Institute of Dental and Craniofacial Research defines as “an infection of the tissues that hold your teeth in place” and is caused by bacteria that inflames the gums.

Yet some researchers are skeptical about a cause-and-effect relationship between the two.

Gum disease and heart disease can be linked in numerous ways, and Harvard Health Publishingmentions studies that may link the bacteria associated with periodontal disease with other ailments such as rheumatoid arthritis and pancreatic cancer.

Yet despite evidence of a connection, some researchers have been skeptical about a cause-and-effect relationship between the two. The Mayo Clinic provides details on why, and reinforces them with some basic reminders about healthy dental habits.

While future studies will continue to shed new light on the relationship between mouths and hearts, doctors agree that daily brushing is a healthy choice — and one that extends beyond your teeth and gums.