Aside from the obvious social implications, getting a bit lax on brushing your teeth can lead to more than just cavities. The same bacteria that causes tooth decay's been linked straight to heart disease, or even stroke, and it's more than just coincidence that "plaque" is used to describe both the stuff in your mouth, and the stuff clogging in your arteries.
It may not be severe enough to really notice, but lax brushing can cause inflammation of the gums, which usually tends to result in bleeding as well. If there's bleeding, then there's a route for bacteria to take into your bloodstream, and people who are already at risk for heart conditions or arthritis could be making things worse for themselves later on by not brushing well enough.
Brushing regularly and well helps keep plaque and bacteria off teeth, but, as Deepak Chopra notes, "teeth make up only about 20% of the surface area in your mouth"—so people who think that brushing alone is enough are sorely mistaken. It really is important to both floss, as well as use some sort of antibacterial rinse, because that other 80% of your mouth can quickly dwarf the freshly cleaned 20%, and reverse any progress made there. Photo by Rodrigo Amorim.
Weekly Health Tip: New Reasons to Brush and Floss | Aol Healthy Living