An oral treatment device, comprising: a thin, flexible, moisture-resistant barrier layer in the shape of a dental tray for protecting an oral treatment composition from saliva and moisture within a persons mouth during use, the barrier layer having a front side wall and a bottom wall that are contiguous so as to form a trough and an oral treatment composition within the trough of the barrier layer comprising an active agent and a tissue adhesion agent having a consistency in a range from a sticky, viscous gel to a solid composition, said oral treatment composition acting as an endoskeleton that prevents the front sidewall and the bottom wall from collapsing together and/or spreading apart prior to use, said oral treatment composition being sticky and adhesive during use so as to cause said barrier layer to at least partially conform to a persons tooth surfaces during use.
