Within a period of time which a user can set, a user points inside of a tooth in order not to decay the tooth. A User can change a background colour, adjust a period of time to play, numbers of teeth to decay and a speed to decay teeth in the first page. When a user wants to play this application, just push the start button which is located on the left top side of the first page. When a user wants to quit this application, just push the stop button which is located below the first page. Please enjoy this game. Thank you.