Horizontal, circular, or vertical brushing? Should you brush for 30 seconds, or over a minute? How much toothpaste should you use, and should you rinse with water afterwards?

We brush our teeth daily, but probably rarely think about the “correct” way to complete this mundane routine. The fact is, nobody really knows what the best way to brush your teeth is — not even dental professionals themselves. That’s what the authors of a new study out of the University College London state, at least.

Published in the British Dental Journal, the study reviewed various dental professionals’ advice on how to brush your teeth — across ten countries. The researchers reviewed what dental associations and dental textbooks all had to say. The consensus was that there seemed to be a lot of conflicting information about brushing teeth, often leaving consumers and patients confused. “The public needs to have sound information on the best method to brush their teeth,” Aubrey Sheiham, Emeritus Professor of Dental Public Health at University College London and senior author of the study, said. “If people hear one thing from a dental association, another from a toothbrush company and something else from their dentist, no wonder they are confused about how to brush. In this study we found an unacceptably inconsistent array of advice from different sources.” Sheiham argues that dental associations need to be more consistent about which method works best.

In the study, the researchers found a variety of recommendations — some dentists advised brushing twice a day, while others said it should be three times. Some recommended to brush at a 45 degree angle, while others said that vertical movements rather than horizontal ones were most effective. As for the length of time, some dentists suggested to brush for two minutes; others claimed three minutes was optimal.

There’s no evidence that complicated methods work any better than a “simple gentle scrub,” Sheiham says. Overall, research is lacking on which technique is best — which is most likely why so many people disagree over the topic. Sheiham recommends to “brush gently with a simple horizontal scrubbing motion, with the brush at a forty-five degree angle to get to the dental plaque. To avoid brushing too hard, hold the brush with a pencil grip rather than a fist. This simple method is perfectly effective at keeping your gums healthy.”

Other dentists, like Dr. John Wainwright, another co-author of the study, suggests “to focus [your] brushing on areas where plaque is most likely to collect — the biting surfaces and where the teeth and gums meet — and to use a gentle scrubbing motion.”

Until a solid study is completed to identify the most effective brushing method, it appears that for the most part it’s a “to each his own” case. Brush for longer than a minute, brush gently and consistently, at least twice a day, and target plaque-y areas — and you should be good.