Look, teeth. Now give us your money.
3. The more you brush your teeth, the merrier.
This common misconception lies in the concept of "if you clean something twice, it'll be cleaner than if you cleaned it once." While true to a limited aspect, brushing your teeth rigorously eight times a day or every time until you can taste your natural saliva again is not generally a good idea. The thing about brushing your teeth is that it's not a magical wand that you can simply wave at your teeth and only expect positive things. Think of this analogy, if you keep mopping your brand new wood floor, your floor is eventually going to collapse.
And everyone you've ever known will die. This is shaping up to be a bad analogy.
The thing is, excessive brushing can lead to other, more serious oral complications. For example, by brushing your teeth religiously, you risk irritating your gums to the point of exposing the roots of your teeth. Along with that, by brushing like a crazed manic, you also risk destroying your teeth enamel, and therefore your teeth itself. Everyone knows that your teeth are among the strongest bones in your body, most if not all of that strength comes from the enamel. By continuing a practice of excessively hard brushing, you could scrape away at the enamel like a waxed floor in a congressman's living room.
2. Brushing your teeth after eating is a good idea
The idea behind this ruse is that if you brush your teeth after eating all your nasty food, you can probably clean away most of the leftover food and avoid having them cling on your teeth, collecting diseases. While this makes perfect sense in a perfect world, there're actually some unforeseen consequences when brushing immediately after eating.
Spontaneous combustion.
In reality, your body has an important duty to carry out after you finish eating, something that you don't help by brushing your teeth. The thing is, every time you eat something that contains acid, your teeth enamel becomes slightly worn down, and by brushing them at this time, you risk damaging your teeth enamel at it's soften state.
Along with this, you're likely to remove the excess saliva in your mouth, (since you salivate more when you eat) which is vital to neutralizing the pH levels surrounding your teeth and naturally removing the food particles in your mouth. By allowing the natural process to continue, you allow your teeth to re-harden and heal. Back to other analogy, it would be similar to sweeping a waxed floor that hasn't dried yet; it's just not a good idea.
1. If my teeth are white, then they are healthy
Putting all these compulsive behaviors aside, lets talk health. A common misconception about teeth in general is that if your teeth are white, then they're healthy and if your teeth are yellow/any color other than brilliant white, they're unhealthy. The problem with this misconception is that it allows people to ignore other diseases that can manifest simply on the basis that their teeth are opal white. Regardless of the color of your teeth, complications such as gum disease, gum regression, tooth decay, and other such diseases are just as possible as with a person with perfectly colored teeth and slightly off colored teeth.
Now you know that your dentist doesn't simply have a sick obsession with drilling away at your teeth.
Using the floor analogy again, it would be comparable to a beautifully waxed floor, with rotten maggot-eaten floor tiles six millimeters below the surface. While your teeth may look glowing white in appearance, you would never know if plaque and tooth decay was be lurking behind your teeth if you ignore the actual health of your teeth in exchange for the vain appearance. Remember that white teeth are a byproduct of a healthy mouth, not the other way around, and unless you plan on getting a nice pair of dentures when you're a old man/woman, be sure to take care of your teeth.
Alternatively, you can remove your teeth now and put them back on when you're older and wiser later.
Tip: Instead of starting the same place when you brush your teeth everyday, try beginning at different locations to ensure that you don't get lazy at a specific point too long. This will ensure that you get every awkward angle, and so that you don't end up two shining front teeth and a pair of yellow fangs.