With crowns in the mouth ,maintaining oral hygeine is very important. You should brush your teeth twice a day and use the dental floss. For application of gum paint take a drop or two of gum paint in your hand and with finger you can massage the gums using clockwise and anticlockwise motion of the finger. The gum paint is very effective if used after doing the warm saline rinses. For more info on oral hygeine you can visit the following link.........http://www.identalhub.com/articlecategory-oral-hygiene-63.aspx