Teach children that teeth are porous and certain foods and beverages can stain the enamel of the teeth. Hard-boil and cool enough white-shelled eggs for each class member. Prepare one cup per child of everyday tea from the grocery store and cool it to lukewarm. Pour all of the tea into a plastic bowl and let the children gently place their eggs into the bowl of tea. Let the eggs sit in the tea for an hour. Seat the class at a table, making sure they all can see, as you pull the eggs one at a time from the bowl. Explain that the tea has left a brown stain on the eggs. Give an egg and a new toothbrush to each child. Apply a dab of toothpaste to the toothbrushes and instruct the children to brush away the stains. Use plenty of paper towels to cushion the eggs and wipe up toothpaste while the children brush the tea stain from the eggs. When the activity is complete, discard the eggs and let the children rinse their toothbrushes well so that they can pop them into a zipper bag to take home.
Use a toothbrush as a paint brush for an art activity that reminds children to brush their teeth thoroughly. Cut tooth-shapes from 9-by-12 in. sheets of yellow construction paper. Draw a shape to use, or download and print a pattern---you can find one at the ABC Teach website (see Resources). Pass a paper tooth shape and a new toothbrush to each child. Squirt blobs of white tempera paint on paper plates and instruct your class to dip their brushes into the paint and apply it to the yellow paper teeth. Explain to the children that to turn the yellow teeth white, they must be sure to brush the paint on every bit of the paper tooth---and to fully clean their teeth as they brush them, they must brush each tooth thoroughly.
Invite a dentist or dental hygienist to visit your classroom to talk to the children about dental health. Learning about tooth care from a professional in the field provides your class with a fresh face to reinforce the message. Your visitor may bring free samples of toothbrushes and floss or other materials that children can take home.
During your regular circle-time, ask each child to name their family dentist and recount some experiences they have had at the dentist's office. Read books designed for preschoolers that deal with the subject of dental hygiene. Visit the library to borrow an assortment of fiction and non-fiction books about tooth care.