Basically, both the manual and the electric brush are good, if you use it correctly. That is, starting with the internal surfaces, then the external ones and then the chewing surfaces. Oh, and do not forget the back teeth!
You should use a short circular motion from the gums, three times on each tooth.
Another advantage of the manual brush is its size, easy to carry on trips and not as expensive as electric ones.
The disadvantage is that manual brushes are for people with limited manual dexterity.
Clinical studies show that electric brushes are better than manual brushes. They perform the brushing movements automatically and more effectively, as long as we give them enough time to brush their teeth – at least 30 seconds per quadrant. It is important to brush your teeth without moving the brush a lot; let him do his job. There are extra soft brushes for sensitive teeth. Some electric brushes have sensors that indicate if a lot of pressure is being applied. Those who have an orthodontic appliance can use a special interdental device. Interdental brushes can also help clean between the teeth.
Even if you choose an electric brush or a manual brush, do not forget to change it every three months or even earlier, if the bristles look worn.