The American Dental Association asserts that a manual toothbrush used correctly is as effective as an electric toothbrush. That is theory. In reality the electric toothbrush delivers a superior cleaning. Manual brushes rely on the operator to maintain a consistent speed and brushing technique for the requisite two minutes. The electric toothbrush is capable of achieving this goal every time with bristles that move thousands of times per minute versus a few hundred times per minute with a manual toothbrush. In choosing an electric toothbrush consider the type of brush head movement for each variety. The rotating brush spins 360 degrees, round oscillating heads oscillate side to side, and sonic brushes vibrate side to side rapidly. Also, consider the costs in choosing which brush will be best for you. A battery operated brush is effective at brushing, but the action is a little more rough than an outlet charged model but it will cost significantly less. There is also the cost and variety of replacement heads to consider. The heads of an electric toothbrush are replaced at the same frequency as a manual toothbrush, approximately every two to three months. Additionally the outlet charged brushes have a few features not found on the battery operated models such as timers and speed adjustment.