Based on the thickness of bristles of tooth brush, it is divided into three types. soft, medium& hard. Usually bristles are made up of nylon.
We should select tooth brush with soft bristles.
Method of brushing
Hold the tooth brush 45degree angle to the gums,brisltles slightly under the gumline.Genlty move the brush back and fro motion and slight circular motion. Brush all the surfaces of teeth including chewing surfaces of backmost teeth and brush the surface of teeth above the tongue.
Proper brushing should be with in two minutes with gentle pressure. Using much pressure more then two minutes can cause loss of tooth structure-abrasion and gum irritation.
Use of interdental aids like interdental brush, floss or water floss to reach narrow areas.