Purchase a tooth blackout wax online or at a costume shop.
Brush your teeth before you begin to apply the wax.
Open the top of the wax container and take out a piece about the size of a pencil eraser, using a tongue depressor. Place the wax onto your work surface.
Form the wax into a square or rectangle shape, using your fingers and the tongue depressor. Look at the tooth you'll be covering in a mirror for reference. Work until you're satisfied with the shape.
Place the wax onto your tooth as you look into the mirror. Form it around the tooth, and use the paintbrush to gently push the wax into the grooves of your teeth. Repeat these steps on other teeth if you want your pirate to have fewer teeth.