Embodiments described herein may help to provide medical support via a fleet of unmanned aerial vehicles. This process makes the tooth more resistant to acid and better able to bond fluoride, thus requiring a lower concentration of fluoride. The water drain pipes passes up through a bore formed through the light coupler body, the coupler further having a light-transmissive portion coupling the lower portion with the upper portion. Some embodiment are also directed to changing the presentation of the wagering game content to 2D, and restoring the one or more portions to 3D based on a degree of player attentiveness after the player looks at the wagering game content again. The insulating projection defines the cavity. The light-to-heat conversion layer is contains at least one kind of polyurethane having at least one carboxyl group, and at least one light-to-heat conversion substance.