My wife is a general dentist and these Dental Wedge Guards go between teeth when you are doing a cavity restoration so you can't nick an adjacent tooth if the drill slips. They are also useful for composite restorations since they are good light blocks and to preserve proper margin spacing between your teeth for proper clearance for flossing and to avoid contact decay.These are different from what she normally uses, but she's getting comfortable with them now. She'll likely purchase the other sizes as well!