Is there evidence that suggests that your teeth will be more healthy if you brush them multiple times per day than when you brush them once per day?
As with just about any instance regarding human physiology/biology: It depends.
Brushing has been shown to remove food particles that will lead to decay. However, brushing can also damage your teeth and gums if you use a brush that has stiff bristles, or brush too vigorously.
The general consensus from dentists seems to indicate that you should gently brush after eating. Although toothpaste is not required for all sessions. And if you have eaten anything acidic, it is best to wait.
According to Peter Heasman, a professor of periodontology at Newcastle University’s School of Dental Sciences, two minutes twice a day brushing with a pressure of 150 grams – equivalent to holding an orange – is correct practice.
In addition, regular dental care (and the associated benefits that are well documented by the entire field of dentistry) can lead to better heart health.