An applicator for oral treatment preparations comprises a membrane covered core having an arched vertical panel and a lateral panel with a generally "L" shaped transverse cross section. The core is formed of a modeling material such as wax, which is soft and pliable and which conforms to the contours of oral surfaces against which it manipulated. The vertical panel is pressed against buccal dentition surfaces to be treated. The lateral panel is then manually bent around occlusal surfaces and pressed against lingual dentition surfaces. The oral treatment preparation for administration may be coated on the membrane prior to fitting or microencapsulated within the core to pass through the membrane for administration. Alternately the applicator is removed after initial shaping or fitting, the oral treatment preparation is applied to the membrane and the applicator is then reinserted.