The goal of dental protection in airsoft is to prevent tooth trauma. This is done by placing a barrier between the teeth and bb’s. This can be done by wearing a mask or by using mouth guard. Mouth guards provide protection of the teeth from both bb tooth impact and head trauma. This is superior protection, but it means having to remove a saliva covered appliance when not playing. It also impairs verbal communication.
I have tested several face masks and found two of them to keep bb’s from passing through to the mouth. They are the Hakkotsu Iron Face mask and the Bitter End lower face mask. I have tested some other mesh style masks which allow bb fragments to pass, but do not allow whole bb’s to break through. They are the Brass Guard masks (Praetorian, BAT, and Stalker) and the Hero